JURUSAN TEKNIK MESIN FAKULTAS TEKNIK UNIVERSITAS MUHAMMADIYAH SURAKARTA

TUGAS AKHIR

STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157

Disusun: LUDI HARTANTO NIM : D 200 020 185

JURUSAN TEKNIK MESIN FAKULTAS TEKNIK UNIVERSITAS MUHAMMADIYAH SURAKARTA

JULI 2009

PERNYATAAN KEASLIAN SKRIPSI

Saya menyatakan dengan sesungguhnya bahwa skripsi dengan judul : “STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157” Yang dibuat untuk memenuhi sebagai syarat memperoleh derajat sarjana S1

pada

Jurusan

Teknik

Mesin

Fakultas

Teknik

Universitas

Muhammadiyah Surakarta, sejauh yang saya ketahui bukan merupakan tiruan atau duplikasi dari skripsi yang sudah dipublikasikan dan pernah dipakai untuk mendapatkan gelar kesarjanaan di lingkungan Universitas Muhammadiyah Surakarta atau instansi manapun, kecuali bagian yang sumber informasinya saya cantumkan sebagaimana mestinya.

Surakarta, 7 Juli 2009 Yang menyatakan,

Ludi Hartanto

ii

HALAMAN PERSETUJUAN

Tugas Akhir berjudul “STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK

KOMPOSIT

BERPENGUAT

SERAT

RAMI

BERMATRIK

POLYESTER BQTN 157”, telah disetujui oleh Pembimbing dan diterima untuk memenuhi sebagai persyaratan memperoleh gelar sarjana S1 pada Jurusan Teknik Mesin Fakultas Teknik Universitas Muhammadiyah Surakarta.

Dipersiapkan oleh : Nama

: LUDI HARTANTO

NIM

: D200 020 185

Disetujui pada Hari

:............................

Tanggal

:............................

Pembimbing Utama

Pembimbing Pendamping

Ir. Agus Hariyanto, MT

Agus Yulianto, ST,MT

iii

HALAMAN PENGESAHAN Tugas Akhir berjudul : “STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK

KOMPOSIT

BERPENGUAT

SERAT

RAMI

BERMATRIK

POLYESTER BQTN 157”. telah dipertahankan di hadapan Tim Penguji dan telah dinyatakan sah untuk memenuhi sebagai syarat memperoleh derajat sarjana S1 pada Jurusan Teknik Mesin Fakultas Teknik Universitas Muhammadiyah Surakarta.

Dipersiapkan oleh :

Nama NIM

: LUDI HARTANTO : D200 020 185

Disahkan pada : Hari :......................... Tanggal :…...................... Tim Penguji : Ketua

: Ir. Agus Hariyanto, MT

………………….

Anggota 1

: Agus Yulianto, ST, MT

..........................

Anggota 2

: Dr.Kuncoro Diharjo, ST,MT ..........................

Dekan,

Ketua Jurusan,

Ir. H Sri Widodo, MT

Marwan Effendy, ST., MT

iv

v

MOTTO

”Jadikanlah sabaar dan shalat sebagai penolongmu. Dan sesungguhnya yang demikian itu sungguh berat, kecuali bagi orang-orang yang khusyu” (Q.S Al Baqarah : 45) ”karena sesungguhnya sesudah kesulitan itu ada kemudahan, maka apabila kamu telah selesai dari sesuatu urusan, kerjakanlah dengan sungguh-sungguh urusan yang lain. Dan hanya kepada Tuhanmulah hendaknya kamu berharap” (Q.S Alam Nasyarah : 6-8) ”Yang paling banyak menjatuhkan orang, itu adalah tidak seimbangnyaantara perkataan dan perbuatan” (Abdullah Gymnastiar) ”Hidup adalah belajar, kehidupan adalah pelajaran. Mati adalah misteri, penentuan dan akherat adalah prestasi hidup. Maka janganlah kamu hidup dengan mimpi-mimpi, tapi hidupkanlah mimpi-mimpimu” (Abdullah Gymnastiar) ”Tak ada pengorbanan maka tak ada kemenangan dan tak ada usaha maka tak akan ada keberhasilan” (Penulis)

vi

PERSEMBAHAN

Sujud syukurku pada-Mu Illahi Robbi yang senantiasa memberikan kemudahan bagi hamba-Nya yang mau berusaha. Petunjuk dan bimbingan-Mu selama hamba menuntut ilmu diperantauan berbuah karya sederhana ini yang kupersembahkan kepada :  Agamaku yang telah mengenalkan aku kepada ALLAH SWT serta Rosul-Nya danmengarahkan jalan dari gelap-gulita menuju terang benderang, terimakasih ALLAH atas ridhonya hingga saya dapat menyelesaikan tugas akhir ini, walaupun kadang keluar dari jalan yang Engkau tetapkan. (“Engkau yang mendengar do’aku dan mengabulkan jerih payahku”).  Ayah dan Ibu tercinta, dengan do’a dan kasih sayang tulusnya selalu senantiasa memberikan kekuatan dalam setiap langkah ananda, terima kasih atas semua pengorbanan yang tidak ternilai harganya.  Saudara-saudaraku yang selalu memberikanku do’a, inpirasi maupun dukungan kepadaku.  Seseorang yang kelak kan menjadi pendampingku, yang telah memberikanku inspirasi, motivasi, dan kesetiaan.  Almamater Fakultas Teknik UMS.

vii

ABSTRAKSI

STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157 Ludi Hartanto., Agus Hariyanto, Agus Yulianto. Teknik Mesin Universitas Muhammadiyah Surakarta JL. A. Yani Pabelan Kartasura Tromol Pos I Sukoharjo

ABSTRAKSI Tujuan dari penelitian ini adalah untuk mengetahui kekuatan bending,tarik dan impak yang optimal dari komposit serat rami pada fraksi volume 20%, 30%, 40%, 50% dengan variasi ketebalan 1mm hingga 5mm,dengan perlakuan alkali serta mengetahui jenis patahan dengan pengamatan makro pada specimen yang memiliki harga optimal dari pengujian bending,tarik dan impak. Pada penelitian ini bahan yang dipergunakan adalah serat ramie yang disusunan acak dengan fraksi volume 20%, 30%, 40%, 50%, dengan variasi tebal 1mm hingga 5mm, menggunakan Polyester BQTN 157 sebagai matriknya. Pembuatan dengan cara press mold, pengujian bending yang dilakukan dengan acuan standar ASTM D 790-02,tarik dengan standart ASTM 638-02 dan Impak charpy dengan acuan standart ASTM D 256-00. Hasil pengujian didapat pengaruh alkali 2,4,6,dan 8 jam pada fraksi volume 20%, 30%, 40%, 50%, dengan variasi tebal 1mm hingga 5mm. Pada pengujian bending optimal rata-rata pada vf 40% dengan ketebalan 3mm dan paling optimal pada alkali 2 jam,Pada uji tarik optimal pada vf 50% ketebalan 5mm dan paling optimal pada alkali 2 jam,dan Pada uji Impak optimal rata-rata pada vf 40% dan 50% pada ketebalan 5mm dan paling optimal pada vf 50% alkali 6 jam. Pengamatan struktur makro didapatkan jenis patahan broken fiber. Kata kunci : Serat Rami, Polyester, Kekuatan, Alkali.

viii

KATA PENGANTAR

Assalamu’alaikum Wr. Wb. Syukur Alhamdulillah, penulis panjatkan kehadirat Allah SWT atas berkah dan rahmat-Nya sehingga penyusun laporan penelitian ini dapat terselesaikan. Tugas Akhir berjudul ”STUDY PERLAKUAN ALKALI DAN FRAKSI VOLUME SERAT TERHADAP KEKUATAN BENDING, TARIK, DAN IMPAK KOMPOSIT BERPENGUAT SERAT RAMI BERMATRIK POLYESTER BQTN 157”, dapat terselesaikan atas dukungan dari pihak. Untuk itu pada kesempatan ini, penulis dengan segala ketulusan dan keikhlasan hati ingin menyampaikan rasa terima kasih dan penghargaan yang sebesar-besarnya kepada : 1. Bapak Ir. H. Sri Widodo, MT, selaku Dekan Fakultas Teknik Universitas Muhammadiyah Surakarta. 2. Bapak Marwan Effendy, ST, MT, selaku Ketua Jurusan Teknik Mesin Fakultas Teknik Universitas Muhammadiyah Surakarta. 3. Bapak Ir. Agus Hariyanto, MT selaku Dosen Pembimbing I yang telah membimbing, mengarahkan, memberikan petunjuk dalam penyusunan Tugas Akhir ini dengan sangat perhatian, baik, sabar dan ramah. 4. Bapak Agus Yulianto, ST, MT, selaku Dosen Pembimbing II yang telah membimbing, mengarahkan, memberikan petunjuk dalam penyusunan Tugas Akhir ini dengan sangat perhatian, baik, sabar dan ramah. 5. Dosen Jurusan Teknik Mesin Universitas Muhammadiyah Surakarta yang telah memberikan ilmu pengetahuan kepada penulis selama mengikuti kegiatan kuliah. 6. Bapak dan Ibu tercinta yang setiap malam selalu mendoakan, memberikan semangat dan dorongan, serta terima kasih atas semua nasehat, bimbingan, dan pengorbanan mu selama ini sehingga penulis

ix

terpacu untuk menyelesaikan skripsi ini. Semua do’a dan kasih sayang yang tulus ini akan selalu mengiringi langkahku” 7. Kakak dan adikku yang slalu memberikan semangat,bantuan dan pengertiannya selama ini. 8. Teman-teman kontrakan Utopia, terima kasih atas segala suka duka yang mewarnai sebagian hari-hari penulis, semoga persaudaraan ini bisa berlangsung lebih lama lagi. Amien. Penulis menyadari bahwa laporan ini masih jauh dari sempurna, oleh karena itu kritik dan saran yang bersifat membangun dari pembaca akan penulis terima dengan senang hati. Wassalamu’alaikum Wr. Wb

Surakarta, 7 Juli 2009

Penulis

x

DAFTAR ISI

HALAMAN JUDUL............................................................................... i PERNYATAAN KEASLIAN SKRIPSI.....................................................ii HALAMAN PERSETUJUAN .............................................................. iii HALAMAN PENGESAHAN ................................................................. iv LEMBAR SOAL TUGAS AKHIR...............................................................v MOTTO ................... ........................................................................... vi ABSTRAKSI.................... ...................................................................... vii KATA PENGANTAR............................................................................ viii DAFTAR ISI .............. ........................................................................... x DAFTAR GAMBAR ....... ...................................................................... xiii DAFTAR TABEL ............ ................................................................. xvii DAFTAR NOTASI............................................................................... xviii DAFTAR LAMPIRAN.......................................................................... xix BAB I PENDAHULUAN 1.1. Latar Belakang Masalah .................................................. 1 1.2. Tujuan Penelitian ............................................................. 2 1.3. Manfaat Penelitian .................................................. 3 1.4. Perumusan masalah........................................................... 4 1.5. Batasan Masalah ................................................................ 4 1.6. Sistem Penulisan Laporan .................................................. 5 BAB II TINJAUAN PUSTAKA DAN LANDASAN TEORI 2.1. Kajian Pustaka ................................................................. 7 2.2. Landasan Teori ............................................................... 9 2.2.1. Definisi Komposit ................................................... 9 2.2.2. Klasifikasi

Material

komposit

berdasarkan

bentuk

komponen strukturalnya ....................................... 11 2.2.3. Unsur-unsur Utama Pembentuk komposit FRP ... 15 2.2.4. Aspek Geometri ................................................... 22 2.2.5. Perpatahan (Frature) ........................................... 33

xi

BAB III METODOLOGI PENELITIAN 3.1. Persiapan Bahan dan Alat.................................................................. 35 3.1.1. Penyiapan Bahan .................................................... 35 3.1.2. Penyiapan Alat ........................................................ 37 3.2. Diagram Alir..................................................................... . . 40 3.2.1. Survey Lapangan dan study literature .................... 41 3.2.2. Penyiapan Bahan .................................................. 41 3.2.3. Pembuatan Komposit.............................................. 41 3.2.4. Pengujian Komposit ................................................ 45 BAB IV DATA HASIL PENELITIAN DAN PEMBAHASAN 4.1. Pengujian Bending ………………………………………..... 53 4.1.1. Data Hasil Pengujian Bending Alkali 2 jam ……... 53 4.1.1.1. Pembahasan Pengujian bending Alkali 2 jam.. 58 4.1.2. Data Hasil Pengujian Bending Alkali 4 jam …….. 60 4.1.2.1. Pembahasan Pengujian bending Alkali 4 jam... 65 4.1.3. Data Hasil Pengujian Bending Alkali 6 jam……... 67 4.1.3.1. Pembahasan Pengujian bending Alkali 6 jam.. 72 4.1.4. Data Hasil Pengujian Bending Alkali 8 jam …….. 74 4.1.4.1. Pembahasan Pengujian bending Alkali 8 jam... 79 4.2. Pengujian Tarik …………………………………………….. 81 4.2.1. Data Hasil Pengujian Tarik Alkali 2 jam ………… 81 4.2.1.1. Pembahasan Pengujian Tarik Alkali 2 jam …… 83 4.2.2. Data Hasil Pengujian Tarik Alkali 4 jam ………... 84 4.2.2.1. Pembahasan Pengujian Tarik Alkali 4 jam …… 86 4.2.3. Data Hasil Pengujian Tarik Alkali 6 jam…………. 87 4.2.3.1. Pembahasan Pengujian Tarik Alkali 6 jam……. 89 4.2.4. Data Hasil Pengujian Tarik Alkali 8 jam ………… 90 4.2.4.1. Pembahasan Pengujian Tarik Alkali 8 jam……. 92 4.3. Pengujian IMPAK …………………………………………... 93 4.3.1. Data Hasil Pengujian Impak Alkali 2 jam ……… 93 4.3.1.1. Pembahasan Pengujian Impak Alkali 2 jam .... 95 4.3.2. Data Hasil Pengujian Impak Alkali 4 jam …….... 96

xii

4.3.2.1. Pembahasan Pengujian Impak Alkali 4 jam .... 98 4.3.3. Data Hasil Pengujian Impak Alkali 6 jam ……...... 99 4.3.3.1. Pembahasan Pengujian Impak Alkali 6 jam..... 101 4.3.4. Data Hasil Pengujian Impak Alkali 8 jam …….... 102 4.3.4.1. Pembahasan Pengujian Impak Alkali 6 jam .... 104 4.4. Pengamatan Struktur makro ………………………………. 105 4.4.1. Pembahasan Foto Makro ……………………….... 107 BAB V KESIMPULAN DAN SARAN 5.1.

Kesimpulan...................................................................... 109

5.2. Saran................................................................................ 111 DAFTAR PUSTAKA LAMPIRAN

xiii

DAFTAR GAMBAR Gambar 2.1 Continous fiber composite .............................................. 11 Gambar 2.2 Woven fiber composite ................................................... 13 Gambar 2.3 Chopped fiber composite ................................................. 14 Gambar 2.4 Hybrid composite ........................................................... 15 Gambar 2.5 Particulate Composite ...................................................... 16 Gambar 2.6 Laminated Composites .................................................... 17 Gambar 2.7 Skema Uji Densitas (Goerge, N B and Brian R. 2003). . 29 Gambar 2.8 Penampang Uji bending (Standart ASTM D 790-02)….. 26 Gambar 2.9 Spesimen dan peralatan uji Impak.................................. 63 Gambar 3.1 Serat rami sebelum diacak ............................................. 85 Gambar 3.2 serat rami setelah diacak ............................................... 86 Gambar 3.3 Resin Polyester Yucalac tipe 157 dan katalis ................. 86 Gambar 3.4 Larutan NaOH................................................................. 87 Gambar 3.5 Timbangan Digital ......................................................... 87 Gambar 3.6. wood moisture meter ..................................................... 88 Gambar 3.7 Cetakan untuk benda uji ................................................. 88 Gambar 3.8. Alat Pengepres Cetakan ................................................ 89 Gambar 3.9 Alat bantu lain ................................................................. 89 Gambar 3.10. Diagram alir penelitian ..................................................40 Gambar 3.11 Hasil cetakan komposit serat Ramie dengan matrik polyester ..................................................................... 90 Gambar 3.12 Spesimen uji tarik komposit serat rami. ....................... 91 Gambar 3.13 Spesimen uji bending komposit serat ramie ................. 91 Gambar 3.14 Spesimen uji Impak komposit serat ramie ................... 92 Gambar 3.15 Dimensi pengujian bending Standar ASTM D 790-02. 46 Gambar 3.16. Mesin Pengujian Bending ............................................ 93 Gambar 3.17 Mesin pengujian Impak charpy .................................... 94 Gambar 3.18 Dimensi Impak ASTM D 5942-96 ................................ 94 Gambar 3.19 Dimensi benda pengujian tarik...................................... 94 Gambar 3.20 Mesin pengujian tarik ................................................... 95

xiv

Gambar 4.1 Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposit …………………………. 55 Gambar 4.2 Grafik hubungan tegangan bending rata-rata dengan fraksi volume terhadap tebal komposit ……………………….. 56 Gambar 4.3 Grafik hubungan defleksi bending rata-rata dengan fraksi volume terhadap tebal komposit ………………………… 56 Gambar 4.4 Grafik hubungan modulus elastisitas bending rata-rata dengan fraksi volume terhadap tebal komposit………. 57 Gambar 4.5 Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit ………………………. 57 Gambar 4.6 Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposit ..................................... 62 Gambar 4.7 Grafik hubungan tegangan bending rata-rata dengan fraksi volume terhadap tebal komposit……………………….. 63 Gambar 4.8 Grafik hubungan defleksi bending rata-rata dengan fraksi volume terhadap tebal komposit……………………….. 63 Gambar 4.9 Grafik hubungan modulus elastisitas bending rata-rata dengan fraksi volume terhadap tebal komposit………. 64 Gambar 4.10 Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit………………………. 64 Gambar 4.11 Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposit………………………. 69 Gambar 4.12 Grafik hubungan tegangan bending rata-rata dengan fraksi volume terhadap tebal komposit………………………. 70 Gambar 4.13 Grafik hubungan defleksi bending rata-rata dengan fraksi volume terhadap tebal komposit……………………… 70 Gambar 4.14 Grafik hubungan modulus elastisitas bending rata-rata dengan fraksi volume terhadap tebal komposit………. 71 Gambar 4.15 Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit……………………… 71 Gambar 4.16 Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposit……………………… 76

xv

Gambar 4.17 Grafik hubungan tegangan bending rata-rata dengan fraksi volume terhadap tebal komposit……………………… 77 Gambar 4.18 Grafik hubungan defleksi bending rata-rata dengan fraksi volume terhadap tebal komposit……………………… 77 Gambar 4.19 Grafik hubungan modulus elastisitas bending rata-rata dengan fraksi volume terhadap tebal komposit…….. 78 Gambar 4.20 Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit……………………… 78 Gambar 4.21 Grafik hubungan modulus elastisitas tarik rata-rata dengan fraksi volume terhadap tebal komposit………………. 82 Gambar 4.22 Grafik hubungan kekuatan tarik rata-rata dengan fraksi volume terhadap tebal komposit……………………… 82 Gambar 4.23 Grafik hubungan modulus elastisitas tarik rata-rata dengan fraksi volume terhadap tebal komposit……………… 85 Gambar 4.24 Grafik hubungan kekuatan tarik rata-rata dengan fraksi volume terhadap tebal komposit………………………85 Gambar 4.25 Grafik hubungan modulus elastisitas tarik rata-rata dengan fraksi volume terhadap tebal komposit……………… 88 Gambar 4.26 Grafik hubungan kekuatan tarik rata-rata dengan fraksi volume terhadap tebal komposit………………………88 Gambar 4.27 Grafik hubungan modulus elastisitas tarik rata-rata dengan fraksi volume terhadap tebal komposit……………… 91 Gambar 4.28 Grafik hubungan kekuatan tarik rata-rata dengan fraksi volume terhadap tebal komposit………………………91 Gambar 4.29 Grafik hubungan Harga Impak rata-rata dengan fraksi volume terhadap tebal komposit……………………… 94 Gambar 4.30 Grafik Hubungan Energi Serap Impak Rata-rata dengan Fraksi Volume Terhadap Tebal Komposit…………… 94

Gambar 4.31 Grafik hubungan Harga Impak rata-rata dengan fraksi volume terhadap tebal komposit…………………….. 97

xvi

Gambar 4.32 Grafik Hubungan Energi Serap ImpakRata-rata dengan Fraksi Volume Terhadap Tebal Komposit……………97 Gambar 4.33 Grafik hubungan Harga Impak rata-rata dengan fraksi volume terhadap tebal komposit……………………… 100 Gambar 4.34 Grafik Hubungan Energi Serap ImpakRata-rata dengan Fraksi Volume Terhadap Tebal Komposit…………… 100 Gambar 4.35 Grafik hubungan Harga Impak rata-rata dengan fraksi volume terhadap tebal komposit……………………… 103 Gambar 4.36 Grafik Hubungan Energi Serap Impak Rata-rata dengan Fraksi Volume Terhadap Tebal Komposit…………… 103 Gambar 4.37 Contoh Patahan Spesimen pada Uji Bending dengan perbedaan waktu alkali………………………………... 105 Gambar 4.38 Contoh Patahan spesimen pada Uji Impak dengan perbedaan waktu alkali………………………………… 106 Gambar 4.39 Contoh Patahan spesimen pada Uji Tarik dengan perbedaan waktu alkali………………………………… 107

xvii

DAFTAR TABEL

Tabel 2.1 Sifat mekanik dari beberapa jenis serat....................................17 Tabel 4.1 Data hasil pengujian bending rata-rata pada tebal 1mm.........53 Tabel 4.2 Data hasil pengujian bending rata-rata pada tebal 2mm.........53 Tabel 4.3 Data hasil pengujian bending rata-rata pada tebal 3mm…….54 Tabel 4.4 Data hasil pengujian bending rata-rata pada tebal 4mm…….54 Tabel 4.5 Data hasil pengujian bending rata-rata pada tebal 5mm…….55 Tabel 4.6 Data hasil pengujian bending rata-rata pada tebal 1mm…….60 Tabel 4.7 Data hasil pengujian bending rata-rata pada tebal 2mm……..60 Tabel 4.8 Data hasil pengujian bending rata-rata pada tebal 3mm……..61 Tabel 4.9 Data hasil pengujian bending rata-rata pada tebal 4mm……..61 Tabel 4.10 Data hasil pengujian bending rata-rata pada tebal 5mm……62 Tabel 4.11 Data hasil pengujian bending rata-rata pada tebal 1mm……67 Tabel 4.12 Data hasil pengujian bending rata-rata pada tebal 2mm……67 Tabel 4.13 Data hasil pengujian bending rata-rata pada tebal 3mm……68 Tabel 4.14 Data hasil pengujian bending rata-rata pada tebal 4mm……68 Tabel 4.15 Data hasil pengujian bending rata-rata pada tebal 5mm……69 Tabel 4.16 Data hasil pengujian bending rata-rata pada tebal 1mm……74 Tabel 4.17 Data hasil pengujian bending rata-rata pada tebal 2mm……74 Tabel 4.18 Data hasil pengujian bending rata-rata pada tebal 3mm……75 Tabel 4.19 Data hasil pengujian bending rata-rata pada tebal 4mm……75 Tabel 4.20 Data hasil pengujian bending rata-rata pada tebal 5mm……76 Tabel 4.21 Hasil Data Pengujian Tarik Alkali 2 Jam……………………..81 Tabel 4.22 Hasil Data Pengujian Tarik Alkali 4 Jam……………………..84 Tabel 4.23 Hasil Data Pengujian Tarik Alkali 6 Jam……………………..87 Tabel 4.24 Hasil Data Pengujian Tarik Alkali 8 Jam……………………..90 Tabel 4.25 Hasil Data Pengujian Impak Alkali 2 Jam…………………..93 Tabel 4.26 Hasil Data Pengujian Impak Alkali 4 Jam…………………..96 Tabel 4.27 Hasil Data Pengujian Impak Alkali 6 Jam…………………..99 Tabel 4.28 Hasil Data Pengujian Impak Alkali 8 Jam…………………..102

xviii

DAFTAR NOTASI

A

= Luas Penampang

E

= Modulus Elastisitas

Eserap

= Energi Yang Terserap

Is

= Kekuatan Impak

L

= Jarak antara tumpuan

P

= Beban Tekan

Vc

= Volume Komposit

Vf

= Fraksi Volume

mu

= Berat Specimen Di udara

ma

= Berat Specimen Dalam air

ρair

= Densitas air

σ

= Tegangan tarik

ΔL

= Deformasi/pemanjangan

xix

DAFTAR LAMPIRAN

Lampiran 1. Annual Book of ASTM Lampiran 2. Data hasil pengujian bending,tarik,dan Impak Lampiran 3. Analisis perhitungan pengujian bending,tarik,dan Impak Lampiran 4. Tabel mechanical properties fiber dan resin Lampiran 5. Uji Density serat rami dengan kadar air 10% Lampiran 6. Analisis perhitungan fraksi volume Lampiran 7. Konversi Satuan Lampiran 8. Gambar mesin pengolahan serat rami

xx

1

BAB I PENDAHULUAN

1.1. Latar Belakang Masalah Penggunaan material komposit dengan filler serat alam mulai banyak dikenal dalam industri manufaktur. Material yang ramah lingkungan, mampu didaur ulang, serta mampu dihancurkan sendiri oleh alam merupakan tuntutan teknologi sekarang ini. Salah satu material yang diharapkan mampu memenuhi hal tersebut adalah material komposit dengan material pengisi (filler) serat alam. Keunggulan yang dimiliki oleh serat alam antara lain : non-abbrasive, densitas rendah, harga lebih murah, ramah lingkungan, dan tidak membahayakan bagi kesehatan. Penggunaan serat alam sebagai filler dalam komposit tersebut terutama untuk lebih menurunkan biaya bahan baku dan peningkatan nilai salah satu produk pertanian. (Fajar, 2008). Serat alam dapat menjadi filler dalam komposit karena kandungan selulosa beberapa serat alam yang memiliki selulosa antara lain kenaf, cantalu, tebu, jagung, abaca, padi, ramie dan lainlain. Tanaman ramie ( Boehmeria Nivea ) adalah sumber bahan baku serat tekstil alam tumbuh-tumbuhan, sebagaimana halnya dengan serat kapas, linen (flax) dan sejenisnya. Sejak jaman dahulu rami digunakan untuk bahan pembuat pakaian dan juga sebagai baju

1

2

perang karena keuletan rami mampu menahan sabetan pedang, bahkan sekarang serat rami diteliti oleh pihak militer untuk bahan pembuatan baju anti peluru (Jamasri, 2008). Dalam penelitian ini menggunakan filler serat ramie, jenis pengikat yang digunakan adalah resin polyester. Resin polyester merupakan salah satu resin termoset yang mudah diperoleh dan digunakan masyarakat umum maupun industri skala kecil maupun besar. Resin polyester ini juga mempunyai kemampuan berikatan dengan serat alam tanpa menimbulkan reaksi dan gas, oleh karena itu resin polyester digunakan dalam penelitian ini. Untuk meningkatkan fungsi guna dari serat ramie yang biasa digunakan untuk bahan tekstil dan kerajinan rakyat menjadi material teknik, maka perlu diteliti dan dikembangkan sebagai bahan komposit yang sesuai sifat fisis dan mekanisnya, sehingga akan tercipta bahan komposit baru.

1.2. Tujuan Penelitian Tujuan penelitian ini adalah : 1. Mengetahui kekuatan bending yang paling optimal dari komposit serat ramie pada fraksi volume serat 20%, 30%, 40%, dan 50% dengan variasi tebal komposit 1 mm, 2 mm, 3 mm, 4 mm, dan 5 mm, dan perlakuan alkali 2 jam , 4 jam , 6 jam , 8 jam ,bermatrik resin poliester tipe BQTN 157.

3

2. Mengetahui kekuatan impak yang paling optimal dari komposit serat ramie pada fraksi volume serat 20%, 30%, 40%, dan 50% dengan variasi tebal komposit 1 mm, 2 mm, 3 mm, 4 mm, dan 5 mm, dan perlakuan alkali 2 jam , 4 jam , 6 jam , 8 jam ,bermatrik resin poliester tipe BQTN 157. 3. Mengetahui kekuatan tarik yang paling optimal dari komposit serat ramie pada fraksi volume serat 20%, 30%, 40%, dan 50% dengan variasi tebal komposit 1 mm, 2 mm ,3 mm, 4 mm, dan 5 mm, dan perlakuan alkali 2 jam, 4 jam, 6 jam, 8 jam ,bermatrik resin poliester tipe BQTN 157. 4.

Mengetahui jenis patahan pengujian bending , impak dan tarik dengan foto makro.

1.3. Manfaat Penelitian Manfat dari penelitian ini adalah sebagai berikut: 1. Bagi peneliti adalah untuk menambah pengetahuan, wawasan dan pengalaman tentang penelitian material komposit. 2. Bagi akademik, penelitian ini dapat digunakan sebagai referensi tambahan untuk penelitian tentang komposit serat alam (natural fibrous composite). 3. Bagi industry dapat digunakan sebagai acua atau pedoman dalam pembuatan komposit yang terbuat dari serat alam, khusunya serat

4

ramie sehingga meningkatkan nilai jual serat ramie sekaligus meningkatkan pendapatan masyarakat khususnya petani ramie.

1.4. Rumusan Masalah Komposit Penguatan Serat (Fibrous Composite) menggunakan serat ramie yang disusun secara acak dan matrik resin polyester sebagai pembentuk material komposit, dengan adanya penambahan fraksi volume dan penambahan variasi tebal, serta perlakuan alkali bagaimanakah performasi dari bahan serat komposit ini? Bagaimana jenis patahan specimen hasil pengujian bendin, impak dan tarik? Permasalahan-permasalahan tersebut akan menjadi topik utama penelitian ini.

1.5. Pembatasan Masalah Agar masalah tidak melebar dari pembahasan utama, maka permasalahan hanya dibatasi pada: 1. Pengujian komposit pada serat ramie yang disusun acak dengan fraksi volume serat 20%, 30%, 40%, dan 50% dan dengan variasi tebal komposit 1mm, 2mm, 3mm, 4mm, dan5 mm, dan perlakuan alkali 2 jam, 4 jam, 6 jam, 8 jam dengan matrik resin polyester tipe BQTN 157. 2. Jenis komposit yang dijadikan sebagai bahan penelitian pada tugas akhir ini adalah jenis fibrous komposit (komposit serat).

5

3. Pengujian komposit berupa uji kekuatan bending (Standart ASTM D 790-02), uji impak (Standart ASTM D 256-00) dan uji tarik (Standart ASTM D 638-02). 4. Benda uji dibuat dengan cara press mold dan menggunakan kaca sebagai cetakan. 5. Serat dengan perlakuan Alkali 2 jam, 4 jam, 6 jam, dan 8 jam.

1.6. Sistematika Penulisan Laporan Laporan penulisan Tugas Akhir ini disusun dengan sistematika sebagai berikut: BAB I PENDAHULUAN Berisi tentang latar belakang, tujuan penelitian, manfaat penelitian,

perumusan

masalah,

pembatasan

masalah,

dan

sistematika penulisan laporan. BAB II TINJAUAN PUSTAKA DAN LANDASAN TEORI Bab ini berisi tentang tinjauan pustaka dan dasar teori. Tinjauan pustaka memuat uraian sistematis tentang hasil-hasil riset yang didapat oleh peneliti terdahulu dan berhubungan dengan penelitian ini. Dasar teori ini dijadikan sebagai penuntun untuk memecahkan masalah yang berbentuk uraian kualitatif atau model matematis.

6

BAB III PELAKSANAAN PENGUJIAN Bab ini berisi tentang diagram alur penelitian, penyiapan benda uji, pembuatan benda uji, serta pengujian mekanis komposit. BAB IV HASIL PENELITIAN DAN PEMBAHASAN Bab ini berisi tentang hasil dan pembahasan pengujian bending, impak, dan tarik dan pengamatan foto makro, serta analisis perhitungan. BAB V KESIMPULAN DAN SARAN Bab ini berisi tentang kesimpulan dan saran. DAFTAR PUSTAKA LAMPIRAN

7

BAB II LANDASAN TEORI

2.1. Tinjauan pustaka Nurkholis (2008), meneliti kekuatan tarik dan impak komposit berpenguat serat rami dengan perlakuan alkali (NaOH) selama 2, 4, 6 dan 8 jam dengan fraksi volume serat 10% dan 90% bermatrik poliester BQTN 157, pembuatan komposit dilakukan dengan pencetakan metode hand lay up menggunakan kaca sebagai cetakannya dan perlakuan post cure 600 selama 4jam, diperoleh kekuatan tarik tertinggi dimiliki oleh komposit serat rami dengan perlakuan alkali 8 jam yaitu sebesar 41,9 MPa dengan modulus elastisitas 2743,15 MPa pada perlakuan alkali 2jam, harga impak tertinggi terjadi pada perlakuan alkali 4 jam yaitu sebesar 0,0725 J/mm2. Fajar (2008), meneliti kekuatan bending dan impak komposit serat rami susun acak dengan matrik polyester BQTN 157 tanpa perlakuan alkali, pembuatan komposit dilakukan dengan metode pres mold. Dari hasil pengujian diperoleh sebagai berikut : pengujian bending didapat nilai tegangan bending rata-rata tertinggi dimiliki oleh komposit dengan Vf 50% pada tebal 5mm sebesar 95,33 MPa dan terendah pada komposit dengan Vf 20% pada tebal 4mm sebesar 44,52 MPa, modulus elastisitas bending rata-rata tertinggi dimiliki oleh komposit dengan Vf 40% pada tebal 1mm sebesar 5462,93 MPa dan

7

8

terendah pada komposit dengan Vf 20% pada tebal 4mm. Untuk harga impak rata-rata tertinggi dimiliki oleh komposit dengan Vf 20% pada tebal 1mm sebesar 0,119 J/mm2 dan terendah pada komposit dengan Vf 40% pada tebal 5mm sebesar 0,024 J/mm2. Junaedi (2008), menguji kekuatan tarik dan impak komposit berpenguat serat rami dengan variasi panjang serat 25mm, 50mm dan 100mm dengan fraksi volume 90% matrik poliester BQTN 157 dan 10% serat rami, pembuatan komposit dengan cara prees mold. Diperoleh kekuatan tarik tertinggi pada komposit dengan panjang serat 100mm yaitu 52,483 MPa, dengan modulus elastisitas 5577,213 MPa, harga impak tertinggi dimiliki oleh komposit dengan panjang serat 50mm yaitu 0,087 J/mm2. Ditinjau dari penelitian yang telah dilakukan diatas, maka dapat disimpulkan bahwa kekuatan bending, impak dan tarik dipengaruhi oleh adanya variasi fraksi volume (Vf) semakin tinggi fraksi volumenya maka semakin tinggi pula kekuatannya. Maka dari itu penulis mencoba meneliti komposit berpenguat serat rami acak dengan perlakuan alkali 2jam, 4jam, 6jam dan 8jam, dengan variasi fraksi volume serat (Vf) 20%, 30%, 40% dan 50% bermatrik polyester BQTN 157, terhadap variasi tebal komposit 1mm, 2mm, 3mm, 4mm dan 5mm.

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2.2. Landasan Teori 2.2.1. Definisi Komposit Kata komposit berasal dari kata “to compose” yang berarti menyusun atau menggabung. Secara sederhana bahan komposit berarti bahan gabungan dari dua atau lebih bahan yang berlainan. Jadi komposit adalah suatu bahan yang merupakan gabungan atau campuran dari dua material atau lebih pada skala makroskopis untuk membentuk material ketiga yang lebih bermanfaat. Komposit dan alloy memiliki perbedaan dari cara penggabungannya yaitu apabila komposit digabung secara makroskopis sehingga masih kelihatan serat maupun matriknya (komposit serat) sedangkan pada alloy / paduan digabung secara

mikroskopis

sehingga

tidak

kelihatan

lagi

unsur-unsur

pendukungnya ( Jones, 1975). Sesungguhnya ribuan tahun lalu material komposit telah dipergunakan dengan memanfaatkannya serat alam sebagai penguat. Dinding bangunan tua di Mesir yang telah berumur lebih dari 3000 tahun ternyata terbuat dari tanah liat yang diperkuat jerami (Jamasri, 2008). Seorang petani memperkuat tanah liat dengan jerami, para pengrajin besi membuat pedang secara berlapis dan beton bertulang merupakan beberapa jenis komposit yang sudah lama kita kenal. Komposit dibentuk dari dua jenis material yang berbeda, yaitu: 1. Penguat (reinforcement), yang mempunyai sifat kurang ductile tetapi lebih rigid serta lebih kuat.

10

2. Matrik, umumnya lebih ductile tetapi mempunyai kekuatan dan rigiditas yang lebih rendah. Pada material komposit sifat unsur pendukungnya masih terlihat dengan jelas, sedangkan pada alloy / paduan sudah tidak kelihatan lagi unsur-unsur pendukungnya. Salah satu keunggulan dari material komposit

bila

dibandingkan

dengan

material

lainnya

adalah

penggabungan unsur-unsur yang unggul dari masing-masing unsur pembentuknya tersebut. Sifat material hasil penggabungan ini diharapkan dapat saling melengkapi kelemahan-kelemahan yang ada pada masing-masing material penyusunnya. Sifat-sifat yang dapat diperbaharui (Jones,1975) antara lain : Sifat-sifat yang dapat diperbaiki antara lain: a. kekuatan (Strength) b. kekakuan (Stiffness) c. ketahanan korosi (Corrosion resistance) d. ketahanan gesek/aus (Wear resistance) e. berat (Weight) f. ketahanan lelah (Fatigue life) g. Meningkatkan konduktivitas panas h. Tahan lama Secara alami kemampuan tersebut diatas tidak ada semua pada waktu yang bersamaan (Jones, 1975). Sekarang ini perkembangan teknologi komposit mulai berkembang dengan pesat. Komposit

11

sekarang ini digunakan dalam berbagai variasi komponen antara lain untuk otomotif, pesawat terbang, pesawat luar angkasa, kapal dan alatalat olah raga seperti ski, golf, raket tenis dan lain-lain.

2.2.2. Klasifikasi

Material

Komposit

Berdasarkan

bentuk

komponen strukturalnya Secara garis besar komposit diklasifikasikan menjadi tiga macam (Jones, 1975), yaitu: 1. Komposit serat (Fibrous Composites) 2. Komposit partikel (Particulate Composites) 3. Komposit lapis (Laminates Composites) 2.2.2.1. Komposit serat (Fibrous Composites) Komposit serat adalah komposit yang terdiri dari fiber dalam matriks. Secara alami serat yang panjang mempunyai kekuatan yang lebih dibanding serat yang berbentuk curah (bulk). Merupakan jenis komposit yang hanya terdiri dari satu lamina atau satu lapisan yang menggunakan penguat berupa serat / fiber. Fiber yang digunakan bisa berupa fibers glass, carbon fibers, aramid fibers (poly aramide), dan sebagainya. Fiber ini bisa disusun secara acak maupun dengan orientasi tertentu bahkan bisa juga dalam bentuk yang lebih kompleks seperti anyaman. Serat merupakan material yang mempunyai perbandingan panjang terhadap diameter sangat tinggi serta

12

diameternya

berukuran

mendekati

kristal.

serat

juga

mempunyai kekuatan dan kekakuan terhadap densitas yang besar (Jones, 1975). Kebutuhan akan penempatan serat dan arah serat yang berbeda menjadikan komposit diperkuat serat dibedakan lagi menjadi beberapa bagian diantaranya: 1) Continous fiber composite (komposit diperkuat dengan serat kontinue).

Gambar 2.1. Continous fiber composite (Gibson, 1994) 2) Woven fiber composite (komposit diperkuat dengan serat anyaman).

Gambar 2.2. Woven fiber composite (Gibson, 1994) 3) Chopped fiber composite (komposit diperkuat serat pendek/acak)

13

Gambar 2.3. Chopped fiber composite (Gibson, 1994) 4) Hybrid composite (komposit diperkuat serat kontinyu dan serat acak).

Gambar 2.4. Hybrid composite (Gibson, 1994)

2.2.2.2. Komposit Partikel (Particulate Composites) Merupakan komposit yang menggunakan partikel serbuk sebagai penguatnya

dan terdistribusi secara merata dalam

matriknya.

Gambar 2.5. Particulate Composite (www.kemahasiswaan.its.ac.id) Komposit ini biasanya mempunyai bahan penguat yang dimensinya kurang lebih sama, seperti bulat serpih, balok, serta bentuk-bentuk lainnya yang memiliki sumbu hampir

14

sama, yang kerap disebut partikel, dan bisa terbuat dari satu atau lebih material yang dibenamkan dalam suatu matriks dengan material yang berbeda. Partikelnya bisa logam atau non logam, seperti halnya matriks. Selain itu adapula polimer yang mengandung partikel yang hanya dimaksudkan untuk memperbesar volume material dan bukan untuk kepentingan sebagai bahan penguat (Jones, 1975). 2.2.2.3. Komposit Lapis (Laminates Composites) Merupakan jenis komposit terdiri dari dua lapis atau lebih yang digabung menjadi satu dan setiap lapisnya memiliki karakteristik sifat sendiri.

Gambar 2.6. Laminated Composites (www.kemahasiswaan.its.ac.id) Komposit ini terdiri dari bermacam-macam lapisan material dalam satu matriks. Bentuk nyata dari komposit lamina adalah:( Jones, 1999) 1. Bimetal Bimetal adalah lapis dari dua buah logam yang mempunyai koefisien ekspansi thermal yang berbeda. Bimetal akan

15

melengkung seiring dengan berubahnya suhu sesuai dengan perancangan, sehingga jenis ini sangat cocok untuk alat ukur suhu. 2. Pelapisan logam Pelapisan logam yang satu dengan yang lain dilakukan untuk mendapatkan sifat terbaik dari keduanya. 3. Kaca yang dilapisi Konsep ini sama dengan pelapisan logam. Kaca yang dilapisi akan lebih tahan terhadap cuaca. 4. Komposit lapis serat Dalam hal ini lapisan dibentuk dari komposit serat dan disusun dalam berbagai orientasi serat. Komposit jenis ini biasa digunakan untuk panel sayap pesawat dan badan pesawat.

2.2.3. Unsur-unsur Utama Pembentuk Komposit FRP FRP (Fiber Reinforced Plastics) mempunyai dua unsur bahan yaitu serat (fiber) dan bahan pengikat serat yang disebut dengan matriks. Unsur utama dari bahan komposit adalah serat, serat inilah yang menentukan karakteristik suatu bahan seperti kekuatan, keuletan, kekakuan dan sifat mekanik yang lain. Serat menahan sebagian besar gaya yang bekerja pada material komposit,

16

sedangkan

matriks

mengikat

serat,

melindungi

dan

meneruskan gaya antar serat (Van Vlack, 2005) Secara

prinsip,

komposit

dapat

tersusun

dari

berbagai kombinasi dua atau lebih bahan, baik bahan logam, bahan organik, maupun bahan non organik. Namun demikian bentuk dari unsur-unsur pokok bahan komposit adalah fibers, particles, leminae or layers, flakes fillers and matrix. Matrik sering disebut unsur pokok body, karena sebagian besar terdiri dari matriks yang melengkapi komposit (Van vlack, 2005).

2.2.3.1. Serat Serat atau fiber dalam bahan komposit berperan sebagai bagian utama yang menahan beban, sehingga besar kecilnya kekuatan bahan komposit sangat tergantung dari kekuatan serat pembentuknya. Semakin kecil bahan (diameter serat mendekati ukuran kristal) maka semakin kuat bahan tersebut, karena minimnya cacat pada material (Triyono,& Diharjo k, 2000). Selain itu serat (fiber) juga merupakan unsur yang terpenting, karena seratlah nantinya yang akan menentukan sifat mekanik komposit tersebut seperti kekakuan, keuletan, kekuatan dsb. Fungsi utama dari serat adalah:

17



Sebagai pembawa beban. Dalam struktur komposit 70% 90% beban dibawa oleh serat.



Memberikan sifat kekakuan, kekuatan, stabilitas panas dan sifat-sifat lain dalam komposit.



Memberikan

insulasi

kelistrikan

(konduktivitas)

pada

komposit, tetapi ini tergantung dari serat yang digunakan. Tabel 2.1. Sifat mekanik dari beberapa jenis serat.( Dieter H. Mueller ) Cotton

Flax

Jute

Kenaf

E-Glass

Ramie

Sisal

Diameter

mm

-

11–33

200

200

5–25

40–80

50– 200

Panjang

mm

10–60

10–40

1–5

2–6

-

60–260

1–5

Kekuatan tarik

MPa

930

1800

400– 1050

GPa

26.5

53.0

69.0– 73.0

61.5

Massa jenis

g/cm3

345– 1035 27.6– 45.0 1.43– 1.52

393– 773

Modulus elastisitas

330– 585 4.5– 12.6 1.5– 1.54

1.5

2.5

1.5–1.6

1.6

2.5–3.0

3.6–3.8

511– 635 9.4– 15.8 1.16– 1.5 2.0– 2.5

Regangan maksimum Spesifik kekuatan tarik Spesifik kekakuan

1.44– 1.50 1.5– 2.7–3.2 1.8

%

7.0–8.0

km

39.2

73.8

52.5

63.2

73.4

71.4

43.2

km

0.85

3.21

1.80

3.60

2.98

4.18

1.07

2.2.3.1.

Matrik

Menurut Gibson (1994), bahwa matrik dalam struktur komposit dapat berasal dari bahan polimer, logam, maupun keramik. Syarat pokok matrik yang digunakan dalam komposit adalah matrik harus bisa meneruskan beban, sehinga serat harus bisa melekat pada matrik dan kompatibel antara serat

18

dan

matrik.

Umumnya

matrik

dipilih

yang

mempunyai

ketahanan panas yang tinggi (Triyono & Diharjo, 2000). Matrik yang digunakan dalam komposit adalah harus mampu meneruskan beban sehingga serat harus bisa melekat pada matrik dan kompatibel antara serat dan matrik artinya tidak ada reaksi yang mengganggu. Menurut Diharjo (1999) pada bahan komposit matrik mempunyai kegunaan yaitu sebagai berikut :  Matrik memegang dan mempertahankan serat pada posisinya.  Pada

saat

pembebanan,

merubah

bentuk

dan

mendistribusikan tegangan ke unsur utamanya yaitu serat.  Memberikan sifat tertentu, misalnya ductility, toughness dan electrical insulation. Menurut Diharjo (1999), bahan matrik yang sering digunakan dalam komposit antara lain : a. Polimer. Polimer merupakan bahan matrik yang paling sering digunakan. Adapun jenis polimer yaitu: 

Thermoset, adalah plastik atau resin yang tidak bisa berubah karena panas (tidak bisa di daur ulang). Misalnya : epoxy, polyester, phenotic.

19



Termoplastik, adalah plastik atau resin yang dapat dilunakkan terus menerus dengan pemanasan atau dikeraskan dengan pendinginan dan bisa berubah karena panas (bisa didaur ulang).

Misalnya :

Polyamid, nylon, polysurface, polyether. b. Keramik. Pembuatan komposit dengan bahan keramik yaitu Keramik dituangkan pada serat yang telah diatur orientasinya dan merupakan matrik yang tahan pada temperatur tinggi. Misalnya :SiC dan SiN yang sampai tahan pada temperatur 1650 C. c. Karet. Karet adalah polimer bersistem cross linked yang mempunyai kondisi semi kristalin dibawah temperatur kamar. d. Matrik logam Matrik cair dialirkan kesekeliling sistem fiber, yang telah diatur dengan perekatan difusi atau pemanasan. e. Matrik karbon. Fiber yang direkatkan dengan karbon sehingga terjadi karbonisasi. Pemilihan matrik harus didasarkan pada kemampuan elongisasi saat patah yang lebih besar dibandingkan dengan

20

filler. Selain itu juga perlunya diperhatikan berat jenis, viskositas, kemampuan membasahi filler, tekanan dan suhu curring, penyusutan dan voids. Voids (kekosongan) yang terjadi pada matrik sangatlah berbahaya, karena pada bagian tersebut fiber tidak didukung oleh matriks, sedangkan fiber selalu akan mentransfer tegangan ke matriks. Hal seperti ini menjadi penyebab munculnya crack, sehingga komposit akan gagal lebih awal. Kekuatan komposit terkait dengan void adalah berbanding terbalik yaitu semakin banyak void maka komposit semakin rapuh dan apabila sedikit void komposit semakin kuat. Dalam pembuatan sebuah komposit, matriks berfungsi sebagai pengikat bahan penguat, dan juga sebagai pelindung partikel dari kerusakan oleh faktor lingkungan. Beberapa bahan matriks dapat memberikan sifat-sifat yang diperlukan sebagai keliatan dan ketangguhan. Pada penelitian ini matrik yang digunakan adalah polimer termoset dengan jenis resin polyester. Matriks polyester paling banyak digunakan

terutama

untuk aplikasi konstruksi ringan, selain itu harganya murah, resin ini mempunyai karakteristik yang khas yaitu dapat diwarnai, transparan, dapat dibuat kaku dan fleksibel, tahan air, tahan cuaca dan bahan kimia. Polyester dapat digunakan

21

pada suhu kerja mencapai 79 0C atau lebih tergantung partikel resin dan keperluannya (Schward, 1984). Keuntungan lain matriks polyester adalah mudah dikombinasikan dengan serat dan dapat digunakan untuk semua bentuk penguatan plastik.

2.2.3.2.

Perlakuan Alkali ( NaOH )

Sifat alami serat adalah Hyrophilic, yaitu suka terhadap air berbeda dari polimer yang hidrophilic.Pengaruh perlakuan alkali terhadap sifat permukaan serat alam selulosa telah diteliti dimana kandungan optimum air mampu direduksi sehingga sifat alami hidropholic serat dapat memberikan ikatan interfecial dengan matrik secra optimal (Bismarck dkk 2002). NaOH merupakan larutan basa yang tergolong mudah larut dalam air dan termasuk basa kuat yang dapat terionisasi dengan sempurna. Menurut teori arrhenius basa adalah zat yang dalam air menghasilkan ion OH negatif dan ion positif. Larutan basa memiliki rasa pahit, dan jika mengenai tangan terasa licin (seperti sabun). Sifat licin terhadap kulit itu disebut sifat kaustik basa. Salah satu indikator yang digunakan untuk menunjukkkan kebasaan

adalah

lakmus

merah.

Bila

lakmus

merah

22

dimasukkan ke dalam larutan basa maka berubah menjadi biru.

2.2.4. Aspek Geometri 2.2.4.1.

Pengujian Kadar Air

Pengujian ini adalah untuk mengetahui jumlah kadar air yang terdapat pada serat rami. Uji ini bertujuan untuk menjaga agar serat rami tetap terjaga kadar airnya yaitu 10%. Pengujian ini menggunakan alat digital wood moisture contain. Pengujian ini mempunyai dua fungsi utama yaitu (standar ASTM D 570-98) : 1. Sebagai panduan mengenai proporsi air yang diserap oleh sebuah bahan. 2. Sebagai tes control mengenai keseragaman sebuah produk. 2.2.4.2.

Fraksi Volume Jumlah kandungan serat dalam komposit, merupakan hal

yang menjadi perhatian khusus pada komposit berpenguat serat. Untuk memperoleh komposit berkekuatan tinggi, distribusi serat dengan matrik harus merata pada proses pencampuran agar mengurangi timbulnya void. Untuk menghitung fraksi volume, parameter yang harus diketahui adalah berat jenis resin, berat jenis serat, berat komposit dan berat serat. Adapun fraksi volume yang ditentukan dengan persamaan (Harper, 1996) :

23

................................................. [2.1]

...................................................... [2.2] Jika selama pembuatan komposit diketahui massa fiber dan matrik, serta density fiber dan matrik, maka fraksi volume dan fraksi

massa

fiber

dapat

dihitung

dengan

persamaan

(Shackelford, 1992) :

........................................................... [2.3] dimana : Wf

: fraksi berat serat

wf

: berat serat

wc

: berat komposit

ρf

: density serat

ρc

: density komposit

Vf

: fraksi volume serat

Vm

: fraksi volume matrik

vf

: volume serat

vm

: volume matrik

2.2.4.3. Uji density Pengujian densitas merupakan pengujian sifat fisis terhadap spesimen, yang bertujuan untuk mengetahui nilai kerapatan massa dari

24

spesimen yang diuji. Rapat massa (mass density) suatu zat adalah massa zat per satuan volume (Goerge, 2003).

𝜌=

𝑚 𝑣

dimana : ρ

= densitas benda (gram/cm3)

m

= massa benda (gram)

v

= volume benda (cm3) Pada benda dengan bentuk yang tidak beraturan, dimana kita

kesulitan untuk menentukan volumenya, kita dapat menghitung densitas dengan hukum Archimedes. Dalam pengujian densitas disini pada prinsipnya menentukan massa spesimen diudara (m udara) dan massa spesimen diair (mair). Massa diudara (mudara) dapat dihitung dengan timbangan digital secara normal yang merupakan massa sesungguhnya. Massa dalam air (mair) dapat dihitung dengan cara massa diudara (mudara) dikurangi gaya keatas, sedangkan gaya ke atas dapat dihitung dengan teori Archimides. Pada teori Archimides dikatakan bahwa suatu benda yang dicelupkan dalam suatu fluida akan mengalami gaya ke atas sama dengan massa fluida yang dipindahkan oleh benda. Jadi dari teori Archimides tersebut dapat diterapkan untuk mencari densitas dengan persamaan rumus perhitungan seperti dibawah ini (Barsoum, 1997) :

𝜌=

(𝑚𝑢𝑑𝑎𝑟𝑎

𝑚𝑢𝑑𝑎𝑟𝑎 − 𝑚𝑓𝑙𝑢𝑖𝑑𝑎 )/𝜌𝑓𝑙𝑢𝑖𝑑𝑎

25

dimana : mudara = massa spesimen diudara (gram) mfluida = massa spesimen dalam fluida/air (gram) ρfluida = densitas fluida/air (gram/cm3) ρ

= densitas spesimen (gram/cm3)

Gambar 2.7. Skema Uji Densitas (Goerge, 2003).

2.2.4.4. Kekuatan Bending Material komposit mempunyai sifat tekan lebih baik dibanding tarik, pada perlakuan uji bending spesimen, bagian atas spesimen terjadi proses tekan dan bagian bawah terjadi proses tarik sehingga kegagalan yang terjadi akibat uji bending yaitu mengalami patah bagian bawah karena tidak mampu menahan tegangan tarik. Dimensi balok dapat kita lihat pada gambar 2.7. berikut ini : (Standart ASTM D 790-02 ).

26

P 2

Gambar 2.8. Penampang Uji bending (Standart ASTM D 790-02) Momen yang terjadi pada komposit dapat dihitung dengan persamaan : 𝑀 = 𝑃 2 . 𝐿 2…………………………………………………….. [2.4] Menentukan

kekuatan

bending

menggunakan

persamaan

(Standart ASTM D790-02) : 𝜎=

𝑀. 𝑌 𝐼

𝑃 𝐿 1 . . 𝑑 =2 2 2 1 3 12 . 𝑏 . 𝑑 1 . 𝑃 .𝐿 .𝑑 =8 1 3 12 . 𝑏 . 𝑑 1 𝑃 .𝐿 = 8 1 2 12 𝑏 . 𝑑 𝜎𝑏 =

3𝑃. 𝐿 … … … … … … … … … … … … … … … … … … … . . … … . [2.5] 2 . 𝑏 . 𝑑2 Sedangkan untuk menentukan modulus elastisitas bending

menggunakan rumus sebagai berikut (Standart ASTM D790- 02) :

27

Eb 

L3 .P ………………………....…….............……….[2.6] 4.b.d 3 .

dimana: b = kekuatan bending (MPa) P = beban yang diberikan(N) L = jarak antara titik tumpuan (mm) b = lebar spesimen (mm) d = tebal spesimen (mm) δ = defleksi (mm) Eb = modulus elastisitas (MPa) Sedangkan kekakuan dapat dicari dengan persamaan (Lukkassen, D., Meidel, A., 2003) : 1

𝐼 = 12 𝑏𝑑3 ........................................................................... [2.7] D = EI ................................................................................. [2.8] dimana : D : kekakuan (N/mm2) E : modulus elastisitas (N/mm2) I : momen inersia (mm4) b : lebar (mm) d : tinggi (mm)

28

2.2.4.5.

Kekuatan Impak

Pengujian impak bertujuan untuk mengukur berapa energi yang dapat diserap suatu material sampai material tersebut patah. Pengujian impak merupakan respon terhadap beban kejut atau beban tiba-tiba (beban impak) (calliester, 2007). Dalam pengujian impak terdiri dari dua teknik pengujian standar yaitu Charpy dan Izod. Pada pengujian standar Charpy dan Izod, dirancang dan masih digunakan untuk mengukur energi impak yang juga dikenal dengan ketangguhan takik (Calliester, 2007). Spesimen Charpy berbentuk batang dengan penampang lintang bujur sangkar dengan takikan V oleh proses permesinan (gambar 2.2.a). Mesin pengujian impak diperlihatkan secara skematik

dengan

(gambar

2.2.b).

Beban

didapatkan

dari

tumbukan oleh palu pendulum yang dilepas dari posisi ketinggian h. Spesimen diposisikan pada dasar seperti pada (gambar 2.2.b) tersebut. Ketika dilepas, ujung pisau pada palu pendulum akan menabrak dan mematahkan spesimen ditakikannya yang bekerja sebagai

titik

konsentrasi

tegangan

untuk

pukulan

impak

kecepatan tinggi. Palu pendulum akan melanjutkan ayunan untuk mencapai ketinggian maksimum h’ yang lebih rendah dari h. Energi yang diserap dihitung dari perbedaan h’ dan h (mgh – mgh’), adalah ukuran dari energi impak. Posisi simpangan lengan

29

pendulum terhadap garis vertikal sebelum dibenturkan adalah α dan posisi lengan pendulum terhadap garis vertikal setelah membentur spesimen adalah β. Dengan mengetahui besarnya energi potensial yang diserap oleh material maka kekuatan impak benda uji dapat dihitung (Standar ASTM D256-00). Eserap = energi awal – energi yang tersisa = m.g.h – m.g.h’ = m.g.(R-Rcos α) – m.g.(R- R.cos β) = mg.R.(cos β - cos α) ..........................................[2.9]

Esrp dimana :

Esrp : energi serap (J) m

: berat pendulum (kg) = 20 kg

g

: percepatan gravitasi (m/s2) = 10 m/s2

R

: panjang lengan (m) = 0,8 m

α

: sudut pendulum sebelum diayunkan = 30o

β

:

sudut

ayunan

pendulum

setelah

mematahkan

specimen Harga impak dapat dihitung dengan :

𝐻𝐼 =

𝐸𝑠𝑟𝑝 𝐴𝑜

................................................................................. [2.10]

dimana : HI

: Harga Impak (J/mm2)

Esrp : energi serap (J) Ao

: Luas penampang (mm2)

30

Gambar 2.9. (a) Spesimen yang digunakan untuk pengujian impak. (b) Skematik peralatan uji impak. (Callister, 2007). Pengujian impak dapat diidentifikasi sebagai berikut : 1. Material yang getas, bentuk patahannya akan bermukaan merata, hal ini menunjukkan bahwa material yang getas akan cenderung patah akibat tegangan normal. 2. Material yang ulet akan terlihat meruncing, hal ini menunjukkan bahwa material yang ulet akan patah akibat tegangan geser. 3. Semakin besar posisi sudut β akan semakin getas, demikian sebaliknya.

Artinya

pada

material

getas,

energy

untuk

31

mematahkan material cenderung semakin kecil, demikian sebaliknya. 2.2.4.6.

Pengujian Kekuatan Tarik

Pengujian tarik bertujuan untuk mengetahui tegangan, regangan, modulus elastisitas bahan dengan cara menarik spesimen sampai putus. Pengujian tarik dilakukan dengan mesin uji tarik atau dengan universal testing standar.(Standar ASTM D 638-02). Hal-hal yang mempengaruhi kekuatan tarik komposit antara lain :(Surdia, 1995). a. Temperatur Apabila temperatur naik, maka kekuatan tariknya akan turun b. Kelembaban Pengaruh

kelembaban

ini

akan

mengakibatkan

bertambahnya absorbsi air, akibatnya akan menaikkan regangan patah, sedangkan tegangan patah dan modulus elastisitasnya menurun. c.

Laju Tegangan

d.

Apabila

laju

tegangan

kecil,

maka

perpanjangan

bertambah dan mengakibatkan kurva tegangan-regangan menjadi landai, modulus elastisitasnya rendah. Sedangkan kalau laju tegangan tinggi, maka beban patah dan modulus elastisitasnya meningkat tetapi regangannya mengecil.

32

Hubungan antara tegangan dan regangan pada beban tarik ditentukan dengan rumus sebagai berikut (Surdia, 1995) P = σ . A atau σ =

P ..................................................... [2.11] A

Catatan: P = beban (N) A = luas penampang (mm2) σ = tegangan (MPa). Besarnya regangan adalah jumlah pertambahan panjang karena pembebanan dibandingkan dengan panjang daerah ukur (gage length). Nilai regangan ini adalah regangan proporsional yang didapat dari garis. Proporsional pada grafik tegangan-tegangan hasil uji tarik komposit.(Surdia, 1995) 

=

L ......................................................................... [2.12] lo

Dimana: 

= Regangan (mm/mm)

ΔL = pertambahan panjang (mm) lo = panjang daerah ukur (gage length), mm Pada daerah proporsional yaitu daerah dimana teganganregangan yang terjadi masih sebanding, defleksi yang terjadi masih bersifat elastis dan masih berlaku hukum Hooke. Besarnya nilai modulus elastisitas komposit yang juga

33

merupakan perbandingan antara tegangan dan regangan pada daerah proporsional dapat dihitung dengan persamaan (Surdia, 1995)

 E =  ........................................................................... [2.13] Dimana: E = Modulus elastisitas tarik (MPa)  = Kekuatan tarik (MPa) 

= Regangan (mm/mm)

2.2.5. Perpatahan (Fracture) 2.2.5.1

Dasar-dasar Perpatahan. Kegagalan dari bahan teknik hampir selalu tidak

diinginkan

terjadi

karena

beberapa

alasan

seperti

membahayakan hidup manusia, kerugian dibidang ekonomi dan gangguan terhadap ketersediaan produk dan jasa. Meskipun penyebab kegagalan dan sifat bahan mungkin diketahui, pencegahan terhadap kegagalan sulit untuk dijamin. Kasus yang sering terjadi adalah pemilihan bahan dan proses yang tidak tepat dan perancangan komponen kurang baik serta penggunaan yang salah. Menjadi tanggung jawab para insinyur untuk mengantisipasi kemungkinan kegagalan dan mencari penyebab

pada

kegagalan

kegagalan lagi(Calliester, 2007).

untuk

mencegah

terjadinya

34

Patah sederhana didefinisikan sebagai pemisahan sebuah bahan menjadi dua atau lebih potongan sebagai respon dari tegangan static yang bekerja dan pada temperatur yang relative rendah terhadap temperatur cairnya. Dua model patah yang mungkin terjadi pada bahan teknik adalah patah liat (ductile fracture) dan patah getas (brittle fracture). Klasifikasi ini didasarkan pada kemampuan bahan mengalami deformasi plastik. Bahan liat (ductile) memperlihatkan deformasi plastik dengan

menyerap

energi

yang

besar

sebelum

patah.

Sebaliknya, patah getas hanya memeperlihatkan deformasi plastik yang kecil atau bahkan tidak ada. Setiap proses perpatahan perambatan diterapkan.

meliputi dua sebagai Jenis

tahap

respon

perpatahan

yaitu

pembentukan

dan

terhadap

tegangan

yang

tergantung

pada

sangat

mekanisme perambatan retak (Callister, 2007).

35

BAB III PELAKSANAAN PENELITIAN

3.1. Penyiapan Bahan dan Alat 3.1.1. Penyiapan bahan Bahan yang digunakan dalam penelitian ini adalah sebagai berikut: a. Serat rami Serat rami dicuci dahulu untuk menghilangkn kotoran yang ada pada serat, kemudian serat dijemur. Setelah melalui proses penjemuran serat dioven sampai kadar air menjadi 10%.

Gbr 3.1. Serat rami sebelum diacak

Gbr 3.2. serat rami setelah diacak

35

36

b. Poliester Matrik yang digunakan Resin Polyester BQTN tipe 157

dengan bahan tambahan katalis yang berfungsi sebagai pengeras resin.

Gambar 3.3. Resin Polyester Yucalac tipe 157 dan katalis

c. NaOH NaOH digunakan untuk menghilangkan kotoran atau lignin pada serat dengan kadar 5 %. NaOH merupakan larutan basa dan terkesan licin.

Gambar 3.4. Larutan NaOH

37

3.1.2. Penyiapan Alat. a. Timbangan digital Timbangan yang digunakan untuk menimbang serat dan polyester adalah timbangan digital.

Gambar 3.5. Timbangan Digital. b. Alat Uji Kadar Air. Alat uji kadar air ini digunakan untuk mengukur kadar air serat rami, dengan ketentuan kadar air 10%.

Gambar 3.6. wood moisture meter.

38

c. Cetakan Benda Uji Cetakan yang digunakan terbuat dari kaca bening dengan ketebalan 3mm, 4mm, dan 5 mm.

Gambar 3.7. Cetakan untuk benda uji. d.

Alat Pengepres Cetakan. Untuk penekan digunakan alat pres mold

Gambar 3.8. Alat Pengepres Cetakan. e. Alat Bantu lain

39

Alat Bantu lain yang digunakan, meliputi : sendok, cutter, gunting, kuas, pisau, spidol, kit mobil, penggaris, dan gelas ukur.

Gambar 3.9. Alat bantu lain.

f. Grenda pemotong dan amplas Grenda pemotong digunakan untuk memotong komposit menjadi spesimen dan untuk menghaluskan permukaan bekas potongan digunakan amplas.

40

3.2. Diagram Alir Mulai Study Literatur dan Survey Lapangan

Persiapan Bahan

Perlakuan Alkali

Serat Rami Dengan Vf 20%, 30%, 40%, 50%

Pembuatan cetakan dengan variasi ketebalan 1mm, 2mm, 3mm, 4mm, dan 5mm,

Resin polyeter dan MEKPO 1%

Pembuatan Komposit Skin dengan serat acak (Mat Fiber Composit) dengan metode pres mold Pembuatan Spesimen sesuai Standart

Pengujian :

Uji bending (ASTM D790-02)

Uji impak (ASTM D256-00)

Uji tarik (ASTM D638-02)

Hasil

Analisa dan Pembahasan

Kesimpulan

Selesai

Gambar 3.10. Diagram alir penelitian

Foto Makro

41

3.2.1. Survey Lapangan dan Study Literature. Proses yang dilakukan pada penelitian ini adalah dengan mengumpulkan data awal sebagai study literature. Study literature bertujuan untuk mengenal masalah yang dihadapi, serta untuk menyusun rencana kerja yang akan dilakukan. Pada studi awal dilakukan langkah-langkah seperti survey dilapangan terhadap hal-hal yang berhubungan dengan penelitian yang akan dilakukan serta mengambil data-data penelitian yang sudah ada untuk dijadikan sebagai pembanding terhadap hasil pengujian yang akan dianalisa. Selain itu pada proses ini juga dilakukan perancangan alat pres-mold yang digunakan untuk membuat spesimen yang sesuai dengan karakter matrik yang dipakai.

3.2.2. Penyiapan bahan Mengumpulkan semua bahan-bahan yang akan digunakan dalam proses pembuatan komposit skin. Diantaranya yaitu serat rami, larutan NaOH dan polyester beserta katalis.

3.2.3. Pembuatan Komposit Proses pembuatan komposit serat rami dengan matrik polyester adalah sebagai berikut:

42

1. Penyiapan serat rami, untuk serat rami dicuci dahulu, kemudian dimasukkan kedalam larutan NaOH 5% selama 2jam, 4jam, 6jam dan 8jam, lalu dikeringkan sampai kadar air mecapai 10%. 2. Setelah serat kering kemudian dilakukan proses pembuatan serat secara acak sesuai bentuk cetakan. 3. Pembuatan cetakan Untuk pengujian bending dan impak menggunakan kaca dengan ketebalan 3mm, 4mm, dan 5mm. Tebal

Ukuran cetakan

Daerah pencetakan

3mm

230 x 205 x 16mm

150 x 125 x 3mm

4mm

230 x 205 x 17mm

150 x 125 x 4mm

5mm

230 x 205 x 18mm

150 x 125 x 5mm

komposit

Untuk tebal komposit 1mm menggunakan tebal cetakan 5mm ditambahkan kaca 4mm kedalam cetakan untuk mengurangi volume cetakan dan penambahan kaca 3mm kedalam cetakan untuk tebal komposit 2mm. 4. Pengolesan wax mold release atau kit motor pada cetakan untuk memudahkan

pengambilan

benda

uji

dari

cetakan

setelah

mengalami proses pengeringan. 5. Resin polyester dicampur dengan katalis untuk membantu proses pengeringan. Katalis yang digunakan sebanyak 1% dari banyaknya resin poliester yang digunakan.

43

6. Penuangan campuran resin sebagian dari takaran kedalam cetakan, dilanjutkan penempatan serat rami yang telah disusun secara acak, kemudian diatas serat dituang kembali sisa campuran resin pada gelas takaran kedalam cetakan sambil dipukul-pukul dengan sendok biar campuran resin masuk kedalam serat yang kemudian ditutup dengan kaca dan ditekan dengan dengan alat penekan. 7. Penutupan dengan menggunakan kaca yang bertujuan agar void yang kelihatan dapat diminimalkan jumlahnya yang kemudian dilakukan pengepresan dengan menggunakan alat pengepres. 8. Proses pengeringan dilakukan sampai benar-benar kering yaitu 5 – 10 jam dan apabila masih belum benar-benar kering maka proses pengeringan dapat dilakukan lebih lama 9. Proses pengambilan komposit dari cetakan yaitu menggunakan pisau ataupun cutter. 10. Benda uji komposit siap untuk dipotong menjadi spesimen benda uji. Berikut beberapa gambar dari Komposit serat Rami dengan menggunakan matrik resin polyester.

44

Gambar 3.11. Hasil cetakan komposit serat Rami dengan matrik polyester

Gambar 3.12. Spesimen uji tarik komposit serat rami

Gambar 3.13. Spesimen uji bending komposit serat rami

45

Gambar 3.14. Spesimen uji impak komposit serat rami.

3.2.4. Pengujian Komposit Pengujian yang dilakukan pada penelitian ini antara lain pengujian bending, pengujian impak,dan foto makro.

3.2.4.1. Pengujian bending. Material komposit mempunyai sifat tekan yang lebih baik dibanding sifat tariknya. Kekuatan tarik di pengaruhi oleh ikatan molekul material penyusunnya. Pada pengujian bending ini bertujuan untuk mengetahui besarnya kekuatan lentur dari material komposit. Pengujian dilakukan dengan jalan memberi beban lentur secara perlahan-lahan sampai spesimen mencapai titik lelah. Pada perlakuan uji bending bagian atas spesimen mengalami proses penekanan dan bagian bawah mengalami proses tarik sehingga akibatnya spesimen mengalami patah bagian bawah karena tidak mampu menahan tegangan tarik. Spesimen uji bending dibuat sesuai standar ASTM D790 – 02.

46

Langkah-langkah pengujian bending yaitu : 1. Mempersiapkan benda uji. 2. Menentukan titik tumpuan dan titik tengah benda uji dengan memberi tanda garis. 3. Menentukan besarnya beban yang digunakan. 4. Meletakkan spesimen pada meja mesin pengujian bending dengan jarak tumpuan dan titik tengah yang telah ditentukan. 5. Putar handle sampai beban menyentuh benda uji dan manometer indikator menunjukkan angka nol. 6. Tentukan putaran jarum penentu waktu untuk pencatatan beban selanjutnya. 7. Catat hasil pengujian bending setiap putaran yang telah ditentukan. 8. Menentukan harga bending.

Gambar 3.15. Dimensi pengujian bending Standar ASTM D 790-02

47

Gambar 3.16. Mesin Pengujian Bending (Laboratorium Material Teknik UMS) 3.2.4.2. Pengujian impak Pada uji impak charpy kita mengukur energi yang diserap untuk mematahkan benda uji. Setelah benda uji patah, bandul berayun kembali. Makin besar energi yang diserap makin rendah ayunan kembali dari bandul. Energi patahan yang diserap biasanya dinyatakan dalam satuan joule. Prinsip dari pengujian impak ini adalah apabila benda uji diberi beban kejut, maka benda akan mengalami proses penyerapan energi sehingga terjadi deformasi plastis yang mengakibatkan patah.

48

Untuk mengetahui ketahanan benda terhadap keadaan patah, maka digunakan metode pengujian impak charphy. Langkah-langkah pengujian impak : 1. Mengukur dimensi dari skin yaitu tebal, lebar, dan panjangnya,

kemudian memberikan no spesimen pada

skin yang akan diuji. 2. Mengangkat beban palu. 3. Meletakkan spesimen pada batang uji atau tumpuan dengan bantuan penjepit. 4. Melepaskan palu atau bandul dengan cara menekan tombol dan menarik handel-nya. 5. Palu akan jatuh dan memukul spesimen secara otomatis. 6. Catat energi serap yang ditunjukkan oleh jarum pada alat uji impak. 7. Hitung harga impak. Keretakan akibat uji impak ada tiga bentuk yaitu : 1. Patahan getas Permukaan patahan terlihat rata dan mengkilap, kalau potongan-potongannya

kita

sambungkan

lagi,

ternyata

keretakannya tidak disertai dengan deformasinya bahan. Patahan jenis ini mempunyai harga impak yang rendah.

49

2. Patahan liat. Permukaan patahan ini tidak rata, nampak seperti buram dan berserat, tipe ini mempunyai harga impak yang tinggi. 3. Patahan campuran. Patahan yang terjadi merupakan campuran dari patahan getas dan patahan liat. Patahan ini paling banyak terjadi.

Gambar 3.17. Mesin pengujian impak charpy ( Laboratorium Material Teknik Mesin UMS )

Gambar 3.18. Dimensi impak ASTM D 5942-96

50

Prinsip dari pengujian impak ini adalah apabila benda uji diberi beban kejut, maka benda akan mengalami proses penyerapan energi sehingga terjadi deformasi plastis yang mengakibatkan perpatahan.

3.2.4.2. Pengujian Tarik Pengujian tarik dilakukan untuk mengetahui besarnya kekuatan tarik dari bahan komposit. Pengujian dilakukan dengan mesin uji “Universal Testing Machine” buatan jepang. Spesimen pengujian tarik di bentuk menurut standar ASTM D 638-03 tipe 4 yang ditunjukkan pada gambar berikut:

Lo=33mm

B=6mm R=14mm

Z=115mm

G Gambar 3.19. Dimensi benda pengujian tarik Dimana: Lo : panjang paralel (mm) b : Lebar (mm) Z : Panjang total spesimen (mm)

51

d : Tebal (mm) A : Lebar pegangan (mm) Langkah-langkah pengujian tarik dalam penelitian ini adalah sebagai berikut: 1. Ukur panjang uji dan penempang uji sebelum diuji. 2. Siapkan mesin uji tarik yang digunakan. 3. Masukkan dan seting kertas milimeter-blok diatas mesin plotter. 4. Pasang spesimen tarik dan pastikan terjepit dengan betul. 5. Jalankan mesin uji tarik. 6. Setelah patah, hentikan proses penarikan secepatnya, catat gaya tarik maksimum dan pertambahan panjangnya. 7. Ambil hasil rekaman mesin plotter dari proses penarikan yang tertuang dalam kertas milimeter-blok.

Gambar 3.20. Mesin pengujian tarik ( Laboratorium Material Teknik Mesin UMS )

52

3.2.4.3. Foto Patahan Makro Pengambilan foto makro bertujuan untuk mengetahui jenis/bentuk patahan dan pola kegagalan yang terjadi pada spesimen komposit akibat pengujian bending dan impak. Objek yang diambil dari penampang patahan dan dari samping untuk pengujian impak sedangkan untuk bending diambil dari samping benda uji. Adapun langkah-langkah pengambilan foto patahan makro adalah sebagai berikut: 1. Nyalakan lampu sebagai sumber cahaya. 2. Letakkan spesimen pada “Stage Plate”.atau meja objek. 3. Memasang lensa repro pada kamera dan atur perbesaran yang diinginkan. 4. Lihat gambar pada “LCD” yaitu pada layar kamera. 5. Fokuskan gambar. 6. Untuk melakukan pemotretan: a. Dilakukan dengan kamera digital Nikon E3500, 7.1 Mega pixel. b. Tekan “Expose” untuk melakukan pemotretan 7. Melihat hasil pemotretan.

53

BAB IV HASIL PENELITIAN DAN PEMBAHASAN

4.1. Pengujian Bending 4.1.1. Data Hasil Pengujian Bending Alkali 2 Jam. Table 4.1.1.1. Data hasil pengujian bending rata-rata pada tebal 1mm

Jenis Komposit

Fraksi volume 20% Fraksi volume 30% Fraksi volume 40% Fraksi volume 50%

Momen Bending Rata-rata

Tegangan Bending Rata-rata

Defleksi Bending Rata-rata

(Nmm)

(MPa)

(mm)

Modulus Elastisitas Bending Rata-rata (MPa)

213,424

55,97055

2,376

1884,05211

4839,83537

228,642

38,70191

3,545

700,82351

3499,27007

205,570

18,24936

4,505

199,97964

2559,10614

599,567

74,30054

1,396

2995,64239

23148,5484

Kekakuan Bending Rata-rata (Nmm2)

Table 4.1.1.2. Data hasil pengujian bending rata-rata pada tebal 2mm

Jenis Komposit





(Nmm)

(MPa)

(mm)


946,775

100,9908

1,852

4069,78937

593,575

34,4637

1,894

989,51153

537,350

33,8882

1,028

1833,96408

39530,369

1838,825

74,4255

1,943

1859,34807

,76933,570

53

Kekakuan Bending Rata-rata (Nmm2) 40217,455

23763,342

54

Tabel 4.1.1.3. Data hasil pengujian bending rata-rata pada tebal 3mm

Jenis Komposit





(Nmm)

(MPa)

(mm)


1198,458

51,4811

2,643

2848,62956

101211,,969

1567,083

39,6608

2,213

1806,63456

151084,496

4241,833

143,9594

2,259

7253,41067

391090,483

1760,166

41,6608

2,831

1300,21282

123368,528



Jenis Komposit





(Nmm)

(MPa)

(mm)


2792,725

67,7365

7,021

1586,66787

139886,556

2983,121

63,8266

6,818

1427,32660

155910,587

1963,054

29,0413

18,968

208,36962

38846,421

6205,170

111,8048

4,830

3091,58165

441537,555


55


Jenis Komposit





(Nmm)

(MPa)

(mm)

Modulus Elastisitas Bending Ratarata (MPa)

4142,133

58,8363

8,797

1327,05801

253517,2649

3790,933

63,5019

12,364

1045,49661

164533,6752

4904,540

67,4877

4,541

2797,49988

586992,0176

6257,060

60,3870

4,433

2175,88513

789882,4878


7000 6257,06 6205,17

Momen bending rata-rata (mm4)

6000 5000 4000 3000 2000

1838,83 1760,17

1000 599,567 0 0%

10%

20%

30%

40%

50%

60%

Fraksi volume (%) Tebal 1mm

Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.1. Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposit.

56

Tegangan bending rata-rata (MPa)

160 140 120

111,8048

100 80 60

74,42552 74,30054 60,38704

40

41,66083

20 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.2. Grafik hubungan tegangan bending rata-rata dengan

Defleksi bending rata-rata (mm)

fraksi volume terhadap tebal komposit. 20 18 16 14 12 10 8 6 4 2 0

4,83 4,433 2,831 1,943 1,396 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.3. Grafik hubungan defleksi bending rata-rata dengan fraksi volume terhadap tebal komposit.

Modulus elastisitas bending rata-rata (MPa)

57

8000 7000 6000 5000 4000 3000

3091,582 2995,642

2000

2175,885 1859,348 1300,213

1000 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.4. Grafik hubungan modulus elastisitas bending rata-rata dengan fraksi volume terhadap tebal komposit.

Kekakuan bending rata-rata (N/mm2)

900000 800000

789882,4878

700000 600000 500000 441537,555

400000 300000 200000

123368,5286 76933,57076 23148,5484

100000 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.5. Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit.

58

4.1.1.

Pembahasan Pengujian Bending Dengan Perlakuan Alkali 2 jam. Dari data-data yang telah diperoleh dapat disimpulkan

bahwa harga kekuatan bending komposit serat acak rami pada spesimen tebal 1mm Vf 50% (74,30054 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 55,97055 MPa, 38,70191 MPa, 18,24936 MPa. Pada spesimen tebal 2mm Vf 20% (100,9908 MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50% yaitu 34,4637 MPa, 33,8882 MPa, 74,4255 MPa. Pada spesimen tebal 3mm Vf 40% (143,9594 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 51,4811 MPa, 39,6608 MPa, 41,6608 MPa. Pada spesimen tebal 4mm Vf 50% (111,8048 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 67,7365 MPa, 63,8266 MPa, 29,0413 MPa. Pada spesimen tebal 5mm Vf 40% (67,4877 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 58,8363 MPa, 63,5019 MPa, 60,3870 MPa. Dari data-data yang telah diperoleh menunjukkan harga kekuatan bending optimal yaitu pada spesimen tebal 3mm Vf 40% sebesar 143,9594 MPa, ini dikarenakan momen material komposit pada variasi ini memiliki harga yang tertinggi. Sedangkan

modulus

elastisitas

rata-rata

tertinggi

komposit serat rami acak pada spesimen tebal 1mm Vf 50% (2995,64239 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%

59

yaitu 1884,05211 MPa, 700,823517 MPa, 199,97964 MPa. Pada spesimen tebal 2mm Vf 20% (4069,78937 MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50%

yaitu 989,51153 MPa,

1833,96408 MPa, 1859,34807 MPa. Pada spesimen tebal 3mm Vf 40% (7253,41067 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50%

yaitu 2848,62956 MPa, 1806,63456 MPa, 1300,21282

MPa. Pada spesimen tebal 4mm Vf 50% (3091,58165 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 1586,66787 MPa, 1427,32660 MPa, 208,36962 MPa. Pada spesimen tebal 5mm Vf 40% (2797,49988 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50%

yaitu 1327,05801 MPa, 1045,49661 MPa, 2175,88513

MPa. Dari data-data yang telah diperoleh harga modulus elastisitas bending optimal yaitu pada spesimen tebal 3mm Vf 40% sebesar 7253,41067 MPa.

60

4.1.2. Data Hasil Pengujian Bending Alkali 4 Jam. Table 4.6. Data hasil pengujian bending rata-rata pada tebal 1mm




(Nmm)

(MPa)

(mm)


62,8666

2,256

2252,5189

5770,58849

33,2409

2,233

960,0569

4663,31747

391,138

34,5953

2,732

624,5529

8100,30505

452,966

55,8130

4,093

887,0887

6897,15191

Jenis Komposit


239,564

193,442


Table 4.7. Data hasil pengujian bending rata-rata pada tebal 2mm




(Nmm)

(MPa)

(mm)


Fraksi volume 20%

574,975

61,0075

2,848

1576,3669

15656,5791

Fraksi volume 30%

641,9

2,671

797,9732

19438,07467

Fraksi volume 40%

1877,15

1,696

3814,1518

82203,3813

Fraksi volume 50%

2455,6

2,052

2160,0695

89834,90114

Jenis Komposit

37,2716

119,5723

99,3298


61

Tabel 4.8. Data hasil pengujian bending rata-rata pada tebal 3mm

Jenis Komposit





(Nmm)

(MPa)

(mm)


1364,750

57,9439

2,591

3611,6808

130378,4937

1293,208

34,0783

1,270

2593,4177

215638,1473

1372,25

46,0235

2,213

2402,9037

130896,9267

2862,916

67,0127

1,371

4896,9335

470495,5037



(MPa)

Defleksi Bending Ratarata (mm)


2532,467

36,0286

6,367

1153,0738

216760,7534

Fraksi volume 30%

4201,533

70,1437

7,012

2111,1889

338571,7448

Fraksi volume 40%

6625,733

64,2087

2,911

3707,22952

1320731,722

Fraksi volume 50%

7748,733

106,4359

4,192

4687,609145

992668,6561



(Nmm) Fraksi volume 20%

Jenis Komposit


62





(Nmm)

(MPa)

(mm)


Fraksi volume 20%

1997,775

48,0787

3,522

2373,4008

209108,7464

Fraksi volume 30%

3800,1166

67,616031

4,168

2255,9084

324737,0704

Fraksi volume 40%

4560,075

67,5851

3,282

2802,1701

513118,2639

Fraksi volume 50%

4121

88,12637

2,719

5053,48233

550364,9035

Jenis Komposit


9000


8000

7748,73

7000 6000

5000 4000

4121

3000

2862,917 2455,6

2000

1000 452,966

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.6. Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposi

63


140 120 106,4359297 99,329893 88,1263793

100 80

67,01279282 55,813064

60 40 20 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.7. Grafik hubungan tegangan bending rata-rata dengan fraksi volume terhadap tebal komposit


8 7 6 5 4,192 4,093

4

3

2,719 2,052 1,371

2 1

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.8. Grafik hubungan defleksi bending rata-rata dengan fraksi volume terhadap tebal komposit


64

6000 5053,48233 4896,933587 4687,609145

5000 4000 3000 2000

2160,0695

1000

887,088

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.9. Grafik hubungan modulus elastisitas bending rata-rata dengan fraksi volume terhadap tebal komposit.


1400000 1200000 1000000

992668,6561

800000 600000

550364,9035 470495,5037

400000 200000

89834,90114 6897,15191

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.10. Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit.

65

4.1.2.1

Pembahasan Pengujian Bending Dengan

Perlakuan Alkali 4 Jam Dari data-data yang telah diperoleh dapat disimpulkan bahwa harga kekuatan bending komposit serat acak rami pada spesimen tebal 1mm Vf 20% (62,8666 MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50% yaitu 33,2409 MPa, 34,5953 MPa, 55,8130 MPa. Pada spesimen tebal 2mm Vf 40% (119,5723 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 61,0075 MPa, 37,2716 MPa, 99,3298 MPa. Pada spesimen tebal 3mm Vf 50% (67,0127 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 57,9439 MPa, 34,0783 MPa, 46,0235 MPa. Pada spesimen tebal 4mm Vf 50% (88,1263 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% 67,585148

MPa.

Pada

yaitu 48,0787 MPa, 67,616031MPa, spesimen

tebal

5mm

Vf

50%

(106,435929 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 36,0286 MPa, 70,1437 MPa, 64,20870 MPa. Dari datadata yang telah diperoleh menunjukkan harga kekuatan bending optimal yaitu pada spesimen tebal 2mm Vf 40% sebesar 119,5723 MPa, ini dikarenakan momen material komposit pada variasi ini memiliki harga yang tertinggi. Sedangkan

modulus

elastisitas

rata-rata

tertinggi

komposit serat rami acak pada spesimen tebal 1mm Vf 20% (2252,5189 MPa), lebih besar dari Vf 30%, Vf 40%, Vf 50% yaitu

66

960,0569 MPa, 624,5529 MPa, 887,0887 MPa. Pada spesimen tebal 2mm Vf 40% (3814,1518 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 1576,3669 MPa, 797,9732 MPa, 2160,0695 MPa. Pada spesimen tebal 3mm Vf 50% (4896,9335 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%


2593,4177 MPa, 2402,90335 MPa. Pada spesimen tebal 4mm Vf 50% (5053,48233 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 2373,4008 MPa, 2255,90842 MPa, 2802,1701 MPa. Pada spesimen tebal 5mm Vf 50% (4687,60914 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%


2111,1889 MPa, 3707,22952 MPa. Dari data-data yang telah diperoleh harga modulus elastisitas bending optimal yaitu pada spesimen tebal 4mm Vf 50% sebesar 5053,48233 MPa.

67


Jenis Komposit





(Nmm)

(MPa)

(mm)



132,652

35,0543

3,706

782,0684

2018,934159

180,1918

30,3453

5,029

396,2280

1942,629864

517,8001

45,8119

647,4459

8351,128725

417,9993

52,1525

1193,8059

9225,10121

3,350

2,426

Table 4.12. Data hasil pengujian bending rata-rata pada tebal 2mm Momen Bending Rata-rata


Defleksi Bending Ratarata

Modulus Elastisitas Bending Rata-rata

Kekakuan Bending Rata-rata

(Nmm)

(MPa)

(mm)

(MPa)

(Nmm2)

Fraksi volume 20%

803,575

85,61409

3,5873

1874,33529

18814,76883

Fraksi volume 30%

2072,55

1,27

5114,59448

123254,4682

Fraksi volume 40%

1577,225

99,39187

1,219

4654,64397

100316,1956

Fraksi volume 50%

2519,5

101,85879

1,4343

3292,70595

136747,1912

Jenis Komposit

120,4369

68


Jenis Komposit





(Nmm)

(MPa)

(mm)


1470,833

64,5698

2,984

3048,1183

107484,7506

1428,5416

36,2652

2,973

1187,4769

99578,8228

3560,1666

123,2598

2,771

5092,3261

267131,7309

2293,5416

53,68071

1,954

2623,5904

244927,5693






(Nmm)

(MPa)

(mm)


Fraksi volume 20%

2271,208

55,28018

2,863

3312,1658

293203,8556

Fraksi volume 30%

3111,983

66,56700

2626,6752

285747,1332

Fraksi volume 40%

2740,995

40,70235

4,292

1243,2007

227115,3075

Fraksi volume 50%

4618,3041

81,56316

3,349

3606,1574

533366,1163

Jenis Komposit

3,859


69





(Nmm)

(MPa)

(mm)

2093,733

30,67423

9,185

3393,2

56,91016

Jenis Komposit


4394,533

7243,866

60,52086

70,23699

9,183

7,545

5,276

Modulus Elastisitas Bending Rata-rata (MPa) 660,8281

Kekakuan Bending Rata-rata (Nmm2) 126236,8127

1297,2945

203167,9703

1513,6803

316967,853

2034,2484

731965,123


8000 7243,8666

7000 6000 5000

4618,304167

4000 3000

2519,5 2293,541667

2000 1000

417,9993333

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.11. Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposit

70


140 120 100

101,8587993

80

81,56316509 70,23699981

60

53,68071386 52,15256141

40 20 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.12. Grafik hubungan tegangan bending rata-rata


dengan fraksi volume terhadap tebal komposit

10 8 6

5,276

4

3,349 2,426 1,954 1,434

2 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm



71

6000 5000 4000 3606,157415 3292,705955

3000

2000

2623,590426 2034,248473

1000

1193,805941

0 0%

10%

20%

30%

40%

50%

60%

Fraksi volume (%)

Tebal 1mm

Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.14. Grafik hubungan modulus elastisitas bending rata-rata dengan fraksi volume terhadap tebal komposit


800000 731965,1235

700000

600000 533366,1163

500000 400000 300000

244927,5693

200000

136747,1912

100000

9225,10121

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.15. Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit

72

4.1.3.1


Perlakuan Alkali 6 Jam Dari data-data yang telah diperoleh dapat disimpulkan bahwa harga kekuatan bending komposit serat acak rami pada spesimen tebal 1mm Vf 50% (52,1525 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 35,0543 MPa, 30,3453 MPa, 45,8119 MPa. Pada spesimen tebal 2mm Vf 30% (120,4369), lebih besar dari Vf 20%, Vf 40%, Vf 50% yaitu 85,61409 MPa, 99,39187 MPa, 101,85879 MPa. Pada spesimen tebal 3mm Vf 40% (123,2598 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 64,5698 MPa, 36,2652 MPa, 53,68071 MPa. Pada spesimen tebal 4mm Vf 50% (81,56316 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 55,28018 MPa, 66,56700 MPa, 40,70235 MPa. Pada spesimen tebal 5mm Vf 50% (70,23699 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 30,67423 MPa, 56,91016 MPa, 60,52086 MPa. Dari data-data yang telah diperoleh menunjukkan harga kekuatan bending optimal yaitu pada spesimen tebal 3mm Vf 40% sebesar 123,2598 MPa, ini dikarenakan momen material komposit pada variasi ini memiliki harga yang tertinggi. Sedangkan

modulus

elastisitas

rata-rata

tertinggi

komposit serat rami acak pada spesimen tebal 1mm Vf 50% (1193,8059 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu

73

782,0684 MPa, 396,2280 MPa, 647,4459 MPa. Pada spesimen tebal 2mm Vf 30% (5114,59448 MPa), lebih besar dari Vf 20%, Vf 40%, Vf 50% 3292,70595

MPa.

yaitu 1874,33529 MPa, 4654,64397 MPa, Pada

spesimen

tebal

3mm

Vf

40%

(5092,3261 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 3048,1183 MPa, 1187,4769 MPa, 2623,5904 MPa. Pada spesimen tebal 4mm Vf 50% (3606,1574 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 3312,1658 MPa, 2626,6752 MPa, 1243,2007 MPa. Pada spesimen tebal 5mm Vf 50% (2034,2484 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 660,8281 MPa, 1297,2945 MPa, 1513,6803 MPa. Dari data-data yang telah diperoleh harga modulus elastisitas bending optimal yaitu pada spesimen tebal 2mm Vf 30% sebesar 5114,59448 MPa.

74


Jenis Komposit


Momen Bending Ratarata (Nmm)

Tegangan Bending Rata-rata (MPa)



Kekakuan Bending Rata-rata 2

(Nmm )

130,662

34,32639

4,125

724,95737

1846,08538

281,029

49,80113

5,539

567,14517

2696,24404

385,953

34,19423

3,308

505,05016

6476,82875

632,544

78,03006

2,102

2093,29932

16217,37964

Table 4.17. Data hasil pengujian bending rata-rata pada tebal 2mm

Jenis Komposit


(MPa)



575,150

61,39330

2,354

1885,20806

18728,78645

686,125

40,02084

1,961

1133,19314

27570,30099

1428,825

89,39942

1,505

3267,25884

71414,83031

2004,075

80,97404

2,190

1638,91647

68252,33662



(Nmm)


(Nmm )

75

Tabel 4.18. Data hasil pengujian bending rata-rata pada tebal 3mm Jenis Komposit


(MPa)



577,875

27,35307

1,780

2022,62093

67304,49059

1257,666

32,79411

2,296

1390,64183

118680,8508

2620,166

86,76242

3,297

3176,77790

179245,5071

4282,166

102,10968

1,736

5474,08931

507225,0836



(Nmm)


(Nmm )

Tabel 4.19. Data hasil pengujian bending rata-rata pada tebal 4mm Momen Bending Rata-rata


Defleksi Bending Ratarata

Modulus Elastisitas Bending Rata-rata

Kekakuan Bending Rata-rata

(Nmm)

(MPa)

(mm)

(MPa)

(Nmm )

Fraksi volume 20%

1889,442

45,44886

3,595

2121,48961

191138,151

Fraksi volume 30%

2755,837

58,92963

1506,94289

164344,4337

Fraksi volume 40%

3723,579

55,59110

4,449

1635,84638

299174,4884

Fraksi volume 50%

4956,520

87,83150

4,289

2907,42209

416628,8935

Jenis Komposit

6,045

2

76

Tabel 4.20. Data hasil pengujian bending rata-rata pada tebal 5mm Jenis Komposit


(MPa)



2203,067

31,59097

4,467

1423,26882

268821,8254

3671,933

61,47096

7,837

1602,08804

253191,2614

5587,133

76,34464

5,047

2757,31646

581851,329

4596,533

44,66811

5,184

1313,34294

470505,990



(Nmm)


(Nmm )


6000 5000

4956,521 4596,533 4282,167

4000 3000 2000

2004,075

1000 632,5447 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.16. Grafik hubungan momen bending rata-rata dengan fraksi volume terhadap tebal komposit

77


120 100

102,109681

80

87,8315065 80,9740418 78,030065

60

44,6681165

40 20 0 0%

10%

20%

30%

40%

50%

60%

Fraksi volume (%)

Tebal 1mm

Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.17. Grafik hubungan tegangan bending rata-rata


dengan fraksi volume terhadap tebal komposit.

9 8 7 6 5 4 3 2 1 0

5,184 4,289 2,19 2,102 1,736

0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm



78

6000 5474,08931

5000 4000 3000

2907,4221

2000

2093,29933 1638,91647 1313,34295

1000 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.19. Grafik hubungan modulus elastisitas bending


rata-rata dengan fraksi volume terhadap tebal komposit.

700000 600000 507225,0836 470505,9907 416628,8935

500000 400000 300000 200000 100000

68252,33662 16217,37964

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.20. Grafik hubungan kekakuan bending rata-rata dengan fraksi volume terhadap tebal komposit

79

4.1.4.1


Perlakuan Alkali 8 Jam Dari data-data yang telah diperoleh dapat disimpulkan bahwa harga kekuatan bending komposit serat acak rami pada spesimen tebal 1mm Vf 50% (78,03006 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 34,32639 MPa, 49,80113 MPa, 34,19423 MPa. Pada spesimen tebal 2mm Vf 40% (89,39942), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 61,39330 MPa, 40,02084 MPa, 80,97404 MPa. Pada spesimen tebal 3mm Vf 50% (102,10968 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 27,35307 MPa, 32,79411 MPa, 86,76242 MPa. Pada spesimen tebal 4mm Vf 50% (87,83150 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 45,44886 MPa, 58,92963 MPa, 55,59110 MPa. Pada spesimen tebal 5mm Vf 40% (76,34464 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50% yaitu 31,59097 MPa, 61,47096 MPa, 44,66811 MPa. Dari data-data yang telah diperoleh menunjukkan harga kekuatan bending optimal yaitu pada spesimen tebal 3mm Vf 50% sebesar 102,10968 MPa, ini dikarenakan momen material komposit pada variasi ini memiliki harga yang tertinggi. Sedangkan

modulus

elastisitas

rata-rata

tertinggi

komposit serat rami acak pada spesimen tebal 1mm Vf 50% (2093,29932 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%

80

yaitu 724,95737 MPa, 567,14517 MPa, 505,05016 MPa. Pada spesimen tebal 2mm Vf 40% (3267,25884 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50%

yaitu 1885,20806 MPa,

1133,19314 MPa, 1638,91647 MPa. Pada spesimen tebal 3mm Vf 50% (5474,089311 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40%

yaitu 2022,62093 MPa, 1390,64183 MPa, 3176,77790

MPa. Pada spesimen tebal 4mm Vf 50% (2907,42209 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 40% yaitu 2121,48961 MPa, 1506,94289 MPa, 1635,84638 MPa. Pada spesimen tebal 5mm Vf 40% (2757,31646 MPa), lebih besar dari Vf 20%, Vf 30%, Vf 50%

yaitu 1423,26882 MPa, 1602,08804 MPa, 1313,34294

MPa. Dari data-data yang telah diperoleh harga modulus elastisitas bending optimal yaitu pada spesimen tebal 3mm Vf 50% sebesar 5474,089311 MPa.

81

4.2.

Pengujian Tarik

4.2.1 Data Hasil Pengujian Tarik Rata-rata Pada Alkali 2 Jam Tabel 4.21. Hasil Data Pengujian Tarik Alkali 2 Jam

Spesimen

Kekuatan Tarik Rata-Rata

Modulus Elastisitas Rata-Rata

20 % T1

0.662

0.797

30 % T1

0.772

0.850

40 % T1

0.906

1.174

50 % T1

1.506

1.747

20 % T2

1.348

3.297

30 % T2

1.994

4.060

40 % T2

2.523

4.875

50 % T2

3.192

5.565

20 % T3

2.193

5.924

30 % T3

3.032

6.756

40 % T3

4.686

28.560

50 % T3

5.941

9.449

20 % T4

4.353

5.208

30 % T4

3.714

5.899

40 % T4

6.018

4.782

50 % T4

11.710

9.069

20 % T5

8.399

5.884

30 % T5

8.377

5.462

40 % T5

9.423

6.341

50 % T5

12.644

8.731

Modulus Elastisitas Tarik Rata-rata (MPa)

82

30 25 20 15

8,731

10

9,069 5,565 1,747

5 0 0

10

Tebal 1 mm

20

Tebal 2 mm

30

40

Fraksi Volume (%) Tebal 3 mm

50

60

Tebal 4 mm

Tebal 5 mm

Gambar 4.21. Grafik hubungan modulus elastisitas tarik ratarata dengan fraksi volume terhadap tebal komposit

Kekuatan Tarik Rata-rata (MPa)

14

12,644 11,710

12 10 8 6

5,941

4

3,192 1,506

2 0 0

Tebal 1mm

10

Tebal 2mm

20

30 Fraksi Volume (%) Tebal 3mm

40

50

Tebal 4mm

60

Tebal 5mm

Gambar 4.22. Grafik hubungan kekuatan tarik rata-rata dengan fraksi volume terhadap tebal komposit

83

4.2.1.1 Pembahasan Pengujian Tarik Alkali 2 Jam Dari hasil pengujian tarik didapatkan harga yang paling optimal pada tebal 5mm Vf 50% yaitu sebesar 12,644 MPa, sedangkan yang terendah adalah komposit serat rami dengan Vf 20% pada tebal 1mm yang mempunyai harga tarik rata- rata 0,662 MPa. Hal ini dipengaruhi oleh fraksi volume dan ketebalan spesimen, semakin tebal dan fraksi meningkat maka harga kekuatan tarik meningkat. Sedangkan untuk Modulus elastisitas tertinggi pada tebal 3mm fraksi volume 40% yaitu sebesar 28,560 MPa,sedangkan terendah adalah pada spesimen fraksi volume 20% ketebalan 1mm yaitu 0,797 MPa.

84

4.2.2 Data Hasil Pengujian Tarik Rata-rata Pada Alkali 4 Jam Tabel 4.22. Hasil Data Pengujian Tarik Alkali 4 Jam Spesimen



20 % T1

0,798

0,878

30 % T1

0,755

0,956

40 % T1

1,868

1,498

50 % T1

1,483

2,025

20 % T2

1,806

3,308

30 % T2

1,663

1,563

40 % T2

3,354

4,921

50 % T2

4,769

7,103

20 % T3

2,845

6,928

30 % T3

3,787

5,942

40 % T3

3,155

6,049

50 % T3

7,613

10,019

20 % T4

4,680

8,275

30 % T4

4,972

7,385

40 % T4

4,852

9,222

50 % T4

6,983

8,919

20 % T5

2,992

7,659

30 % T5

4,530

9,801

40 % T5

4,988

8,909

50 % T5

9,581

12,244


85

14 12

12,244

10

10,019 8,919

8 6

7,103

6,049

4 2

2,025

0 0

10

20

30

40

50

60


Tebal 2 mm

Tebal 3 mm

Tebal 4 mm

Tebal 5 mm

Gambar 4.23. Grafik hubungan modulus elastisitas tarik rata-


rata dengan fraksi volume terhadap tebal komposit

12 10

9,581

8

7,613 6,983

6

4,769

4 2

1,483

0 0

Tebal 1mm

10

Tebal 2mm

20


40

50

Tebal 4mm

60

Tebal 5mm


86

4.2.2.1 Pembahasan Pengujian Tarik Alkali 4 Jam Dari hasil pengujian tarik didapatkan harga yang paling optimal pada tebal 5mm Vf 50% yaitu sebesar 9,581 MPa, sedangkan yang terendah adalah komposit serat rami dengan Vf 30% pada tebal 1mm yang mempunyai harga tarik rata- rata 0,755 MPa. Sedangkan untuk Modulus elastisitas tertinggi pada tebal 5mm fraksi

volume 50% yaitu sebesar 12,244 MPa,sedangkan

terendah adalah pada spesimen fraksi volume 20% ketebalan 1mm yaitu 0,878 MPa.

87

4.2.3 Data Hasil Pengujian Tarik Rata-rata Pada Alkali 6 Jam Tabel 4.23. Hasil Data Pengujian Tarik Alkali 6 Jam. Spesimen



20 % T1

0,601

0,886

30 % T1

1,059

1,128

40 % T1

1,388

1,568

50 % T1

2,352

3,096

20 % T2

1,856

2,700

30 % T2

1,971

5,536

40 % T2

4,824

7,293

50 % T2

5,164

5,205

20 % T3

2,738

5,420

30 % T3

3,350

7,040

40 % T3

4,920

6,533

50 % T3

6,740

9,554

20 % T4

3,402

7,451

30 % T4

5,379

9,314

40 % T4

6,604

8,290

50 % T4

5,357

8,917

20 % T5

4,270

8,504

30 % T5

5,858

9,652

40 % T5

6,465

7,410

50 % T5

10,091

11,638


88

14 12

11,638

10

9,554 8,917

8 6

5,205

4

3,096

2

0 0

10

20

30

40

50

60


Tebal 2 mm

Tebal 3 mm

Tebal 4 mm

Tebal 5 mm

Gambar 4.25. Grafik hubungan modulus elastisitas tarik ratarata dengan fraksi volume terhadap tebal komposit


12 10,091

10 8

6,740 5,357 5,164

6

4 2,352

2 0 0

Tebal 1mm

10

Tebal 2mm

20


40

50

Tebal 4mm

60

Tebal 5mm


89




90

4.2.4 Data Hasil Pengujian Tarik Rata-rata Pada Alkali 8 Jam Tabel 4.24. Hasil Data Pengujian Tarik Alkali 8 Jam

Spesimen 20 % T1

Kekuatan Tarik Rata-Rata 0,604

Modulus Elastisitas Rata-Rata 0,895

30 % T1

1,222

1,908

40 % T1

1,132

1,213

50 % T1

1,788

3,309

20 % T2

1,448

2,825

30 % T2

2,262

4,441

40 % T2

3,663

6,784

50 % T2

3,785

6,919

20 % T3

2,684

5,557

30 % T3

3,307

5,657

40 % T3

4,272

6,898

50 % T3

7,751

9,318

20 % T4

3,323

7,485

30 % T4

4,131

7,596

40 % T4

5,713

10,160

50 % T4

10,062

8,705

20 % T5

5,679

12,173

30 % T5

6,093

11,420

40 % T5

7,931

11,122

50 % T5

7,174

10,558


91

14

12 10,558 9,318 8,705

10 8

6,919

6 4

3,309

2 0 0

10

20

30

40

50

60


Tebal 2 mm

Tebal 3 mm

Tebal 4 mm

Tebal 5 mm

Gambar 4.27. Grafik hubungan modulus elastisitas tarik rata-


rata dengan fraksi volume terhadap tebal komposit

12 10

10,062

8

7,751 7,174

6 4

3,785

2

1,788

0 0

Tebal 1mm

10

Tebal 2mm

20


40

50

Tebal 4mm

60

Tebal 5mm


92




93

4.3.

Pengujian Impak

4.3.1. Data Hasil Pengujian Impak Rata-rata Pada Alkali 2 Jam Tabel 4.25. Hasil Data Pengujian Impak Alkali 2 Jam Spesimen

Kekuatan Impak RataRata

Energi yang terserap Rata-rata

20 % T1

0,433

2,522

30 % T1

0,467

3,761

40 % T1

0,700

7,016

50 % T1

0,733

7,289

20 % T2

0,867

9,254

30 % T2

0,767

12,047

40 % T2

0,600

9,716

50 % T2

0,967

18,619

20 % T3

1,067

17,757

30 % T3

1,133

21,379

40 % T3

1,167

23,307

50 % T3

1,067

23,421

20 % T4

1,433

29,375

30 % T4

1,133

28,023

40 % T4

1,267

32,180

50 % T4

1,500

35,908

20 % T5

1,667

47,014

30 % T5

1,633

45,242

40 % T5

1,733

48,920

50 % T5

1,700

48,555

94

2

Harga impak rata-rata (J/mm2)

1,8

1,7

1,6

1,5

1,4

1,2 1,067 0,967

1 0,8

0,733

0,6 0,4 0,2 0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

tebal 5mm

Gambar 4.29. Grafik hubungan Harga Impak rata-rata dengan

Energi terserap impak rata-rata (J/mm2)

fraksi volume terhadap tebal komposit. 60 50

48,555

40

35,908

30 23,421 18,619

20 10

7,289

0 0%

10%

20%

30%

40%

50%

60%

Fraksi volume (%)

Tebal 1mm

Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.30. Grafik Hubungan Energi Serap Impak Rata-rata dengan Fraksi Volume Terhadap Tebal Komposit.

95

4.3.1.1 Pembahasan Pengujian Impak Dengan Alkali 2 Jam Dari hasil pengujian Impak didapatkan harga yang paling optimal pada Vf 40% dengan tebal 5mm yaitu sebesar 1,733 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak rata- rata 0,433 J/mm². Hal ini dipengaruhi oleh luasan daerah Impak semakin luas daerah Impak semakin kecil pula harga Impak komposit tersebut. Dan energi terserap Impak yang paling tinggi pada Vf 40% dengan tebal 5mm yaitu sebesar 48,920 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak rata- rata 2,522 J/mm².

96

4.3.2. Data Hasil Pengujian Impak Rata-rata Pada Alkali 4 Jam Tabel 4.26. Hasil Data Pengujian Impak Alkali 4 Jam

Spesimen



20 % T1

0,500

3,188

30 % T1

0,533

4,343

40 % T1

0,700

7,428

50 % T1

0,767

7,578

20 % T2

0,833

8,869

30 % T2

0,800

12,586

40 % T2

0,700

11,254

50 % T2

1,000

19,304

20 % T3

1,133

18,873

30 % T3

1,233

23,236

40 % T3

1,067

21,357

50 % T3

1,433

31,457

20 % T4

1,467

30,026

30 % T4

1,233

30,384

40 % T4

1,533

38,947

50 % T4

1,567

37,683

20 % T5

1,467

41,267

30 % T5

1,633

45,155

40 % T5

1,767

49,961

50 % T5

1,767

50,555


97

2 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0

1,767 1,567 1,433 1 0,767

0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.31. Grafik hubungan Harga Impak rata-rata dengan fraksi


volume terhadap tebal komposit.

60 50,555

50 40 30

37,683 31,457

20

19,304

10

7,578

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm


98

4.3.2.1 Pembahasan Pengujian Impak Dengan Alkali 4 Jam Dari hasil pengujian Impak didapatkan harga yang paling optimal pada Vf 40% dan Vf 50% dengan tebal 5mm yaitu sebesar 1,767 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak ratarata 0,500 J/mm². Dan energi terserap Impak yang paling tinggi pada Vf 50% dengan tebal 5mm yaitu sebesar 50,555 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak rata- rata 3,188 J/mm².

99


Spesimen



20 % T1

0,533

3,206

30 % T1

0,500

3,998

40 % T1

0,600

5,669

50 % T1

0,700

6,962

20 % T2

0,900

9,562

30 % T2

0,733

11,541

40 % T2

0,800

12,506

50 % T2

1,133

15,720

20 % T3

1,000

16,701

30 % T3

1,267

23,711

40 % T3

1,267

25,206

50 % T3

1,333

29,245

20 % T4

1,233

25,240

30 % T4

1,267

31,399

40 % T4

1,533

38,979

50 % T4

1,733

41,514

20 % T5

1,567

44,231

30 % T5

1,667

46,135

40 % T5

1,700

48,132

50 % T5

1,833

52,704


100

2 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0

1,833 1,733 1,333 1,133 0,7

0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm




60 52,704

50 40

41,514

30

29,245

20 15,72 10

6,962

0 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm


101

4.3.3.1 Pembahasan Pengujian Impak Dengan Alkali 6 Jam Dari hasil pengujian Impak didapatkan harga yang paling optimal pada Vf 50% dengan tebal 5mm yaitu sebesar 1,833 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 30% pada tebal 1mm yang mempunyai harga Impak rata- rata 0,500 J/mm². Dan energi terserap Impak yang paling tinggi pada Vf 50% dengan tebal 5mm yaitu sebesar 52,704 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak rata- rata 3,206 J/mm².

102


Spesimen



20 % T1

0,533

3,273

30 % T1

0,533

4,409

40 % T1

0,667

6,045

50 % T1

0,800

7,949

20 % T2

0,833

8,904

30 % T2

0,967

15,213

40 % T2

0,767

11,922

50 % T2

0,933

12,997

20 % T3

1,133

18,873

30 % T3

1,167

21,833

40 % T3

1,233

24,468

50 % T3

1,367

29,980

20 % T4

1,133

23,191

30 % T4

1,433

35,444

40 % T4

1,433

36,438

50 % T4

1,700

40,737

20 % T5

1,633

46,026

30 % T5

1,600

44,432

40 % T5

1,667

46,971

50 % T5

1,733

47,617


103

2 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0

1,733 1,7 1,367 0,933 0,8

0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm




50 45 40 35 30 25 20 15 10 5 0

47,617 40,737 29,98

12,997 7,949 0%

10%

20%

30%

40%

50%

60%


Tebal 2mm

Tebal 3mm

Tebal 4mm

Tebal 5mm

Gambar 4.36. Grafik Hubungan Energi Serap Impak Rata-rata dengan Fraksi Volume Terhadap Tebal Komposit

104

4.3.4.1 Pembahasan Pengujian Impak Dengan Alkali 8 Jam Dari hasil pengujian Impak didapatkan harga yang paling optimal pada Vf 50% dengan tebal 5mm yaitu sebesar 1,733 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 20%, 30% pada tebal 1mm yang mempunyai harga Impak rata- rata 0,533 J/mm². Dan energi terserap Impak yang paling tinggi pada Vf 50% dengan tebal 5mm yaitu sebesar 47,617 J/mm2 sedangkan yang terendah adalah komposit serat rami dengan Vf 20% pada tebal 1mm yang mempunyai harga Impak rata- rata 3,273 J/mm².Hal ini dipengaruhi oleh fraksi volume dan ketebalan spesimen,semakin tebal dan meningkatnya fraksi volume maka harga energi serapnya meningkat.

105

4.4.

Pengamatan Stuktur Makro Pengamatan struktur makro dilakukan pada bentuk patahan

benda uji. Berikut ini adalah data gambar-gambar foto patahan makro, seperti ditunjukkan pada gambar: 1mm

1mm

Matrik Serat rami

Vf 40% 3mm 2 jam

1mm

1mm

Vf 40% 2mm 4 jam

Patahan akibat gaya tekan 1mm

Patahan akibat gaya tarik

Patahan akibat gaya tekan Patahan akibat gaya tarik

Vf 40% 3mm 6 jam

Vf 50% 3mm 8 jam

an

Gambar 4.37.Contoh Patahan Spesimen pada Uji Bending dengan perbedaan waktu alkali. 1mm

Broken fiber

Serat rami

Kegagalan akibat patah getas

Matrik Vf 40% 5mm 2 jam

106

1mm

Vf 40% 5mm 4 jam 1mm

Vf 50% 5mm 6 jam 1mm

Serat rami

Broken fiber

Kegagalan akibat patah getas

Matrik

Vf 50% 5mm 8 jam Gambar 4.38.Contoh Patahan spesimen pada Uji Impak dengan perbedaan waktu alkali.

107

1mm

1mm

Vf 50% 5mm 2 jam

1mm

Vf 50% 5mm 4 jam

1mm

Matrik Broken fiber Serat rami

Vf 50% 5mm 6 jam

Vf 50% 4mm 8 jam

Gambar 4.39.Contoh Patahan spesimen pada Uji Tarik dengan perbedaan waktu alkali. 4.4.1. Pembahasan Foto Patahan Dari hasi foto patahan dapat dilihat bahwa jenis patahan yang terjadi adalah patahan jenis broken fiber. Patahan broken fiber yaitu patahan pada spesimen dimana serat mengalami patah

108

atau rusak dan membentuk seperti serabut. Hal ini disebabkan oleh distribusi matrik dengan serat kurang merata dan adanya void di sekitar serat. Pada bentuk patahan dapat disimpulkan bahwa jenis patahan yang terjadi adalah patah getas. Arah dari perambatan retak adalah tegak lurus dengan arah tegangan tarik yang bekerja dan menghasilkan permukaan yang relatif rata.

109

BAB V KESIMPULAN DAN SARAN

5.1.

KESIMPULAN Dari hasil penelitian dan analisa pengujian serta pembahasan data

yang diperoleh, dapat disimpulkan: 1 Kekuatan bending rata-rata komposit serat (fibrous composite) serat rami acak dengan perlakuan alkali 2 jam,4 jam,6 jam dan 8 jam yang optimal yaitu :

 Pada alkali 2 jam tebal 3mm Vf 40% sebesar 143,9594 MPa.  Pada alkali 4 jam tebal 2mm Vf 40% sebesar 119,5723 MPa.  Pada alkali 6 jam tebal 3mm Vf 40% sebesar 123,2598 MPa.  Pada alkali 8 jam tebal 3mm Vf 50% sebesar 102,1096 MPa. Dari data-data yang telah diperoleh menunjukkan harga kekuatan bending yang paling optimal yaitu pada alkali 2 jam tebal spesimen 3mm Vf 40% yaitu sebesar 143,9594 MPa. 2 Untuk harga tarik rata-rata komposit serat (fibrous composite) serat rami acak dengan perlakuan alkali 2 jam,4 jam,6 jam dan 8 jam yang optimal yaitu :  Pada alkali 2 jam tebal 5mm Vf 50% sebesar 12,644 MPa.  Pada alkali 4 jam tebal 5mm Vf 50% sebesar 9,581 MPa.  Pada alkali 6 jam tebal 5mm Vf 50% sebesar 10,091 MPa.  Pada alkali 8 jam tebal 4mm Vf 50% sebesar 10,062 MPa. 109

110

Dari data-data yang telah diperoleh harga tarik yang paling optimal komposit serat rami acak yaitu pada alkali 2 jam tebal 5mm Vf 50% sebesar 12,644 MPa. 3 Kekuatan impak rata-rata komposit serat (fibrous composite) serat rami acak dengan perlakuan alkali 2 jam,4 jam,6 jam dan 8 jam yang optimal yaitu :

 Pada alkali 2 jam tebal 5mm Vf 40% sebesar 1,733 J/mm2  Pada alkali 4 jam tebal 5mm Vf 40% sebesar 1,767 J/mm2  Pada alkali 6 jam tebal 5mm Vf 50% sebesar 1,833 J/mm2  Pada alkali 8 jam tebal 5mm Vf 50% sebesar 1,733 J/mm2 Dari data-data yang telah diperoleh menunjukkan harga kekuatan impak yang paling optimal yaitu pada alkali 6 jam tebal spesimen 5mm Vf 50% yaitu sebesar 1,833 J/mm2 4

Pengamatan Foto Makro Dari hasi foto patahan dapat dilihat bahwa jenis patahan yang terjadi adalah patahan jenis broken fiber. Patahan broken fiber yaitu patahan pada spesimen dimana serat mengalami patah atau rusak dan membentuk seperti serabut. Pada bentuk patahan dapat disimpulkan bahwa jenis patahan yang terjadi adalah patah getas. Arah dari perambatan retak adalah tegak lurus dengan arah tegangan tarik yang bekerja dan menghasilkan permukaan yang relatif rata.

111

5.2.

SARAN Dari hasil proses percetakan ada beberapa hal yang perlu diperhatikan, diantaranya: 1 Pada proses pembuatan serat acak hendaknya serat disusun merata agar

memudahkan pencetakan,dan menghasilkan

cetakan komposit yang tebalnya sama dalam satu bidang. 2 Meminimalkan keberadaan rongga udara (void) pada komposit yang akan dibuat sehingga akan menaikkan kekuatan komposit dengan menggunakan alat tekan yang lebih baik. 3 Dalam melakukan pembuatan benda uji hendaknya memakai alat pengaman, karena bahan benda uji merupakan bahan kimia. 4 Pada proses penuangan matrik kedalam serat harus merata dan cepat

agar serat benar-benar terbungkus oleh matrik,

sehingga dapat meminimalkan terjadinya void. 5 Dalam melakukan pengujian hendaknya dilakukan sendiri agar kita mengetahui proses pengujian tersebut.

DAFTAR PUSTAKA ASTM. D 790 – 02 Standard test methods for flexural properties of unreinforced and reinforced plastics and electrical insulating material. Philadelphia, PA : American Society for Testing and Materials. ASTM. D 570 – 98 Standard test method for water absorption of plastics. Philadelphia, PA : American Society for Testing and Materials. ASTM. D 256 – 00 Standard test methods for determining the izod pendulum impact resistance of plastics. ASTM. D 638-02 Standart test method for tensile properties of plastics. Philadelphia, PA : American Society for Testing and Materials. Callister, W. D., 2007, Material Science and Enginering, An Introduction 7ed, Department of Metallurgical Enginering The University of Utah, John Willey and Sons, Inc. Diharjo, K., dan Triyono, T., 2003, Buku Pegangan Kuliah Material Teknik, Universitas Sebelas Maret, Surakarta. Fajar, S.N., 2008, Optimasi Kekuatan Bending Dan Impact Komposit Berpenguat Serat Ramie Bermatrik Polyester Bqtn 157 Terhadap Fraksi Volume Dan Tebal Skin Gibson, 1994.Principle Of Composite Material Mechanics. New York : Mc Graw Hill,Inc. Nurkholis., 2008, Analisis Sifat Tarik dan Impak Komposit Serat Rami Dengan Perlakuan Alkali Dalam Waktu 2, 4, 6, dan 8 jam, Fraksi Volume Serat 10% Dengan Matrik Poliester BQTN 157. Harper, A. C., 1996, Handbook of Plastics, Elastomers and Composites, Mc Graw Hill Componies, Inc. Jones, M. R., 1975, Mechanics of Composite Material, Mc Graww Hill Kogakusha, Ltd. Junaedi, 2008, Penelitian Kekuatan Tarik dan Impak Komposit Serat Rami Dengan Variasi Panjang Serat 25mm, 50mm, dan 100mm, Dengan Fraksi Volume Serat 10% Dengan Matrik Poliester BQTN 157.

Lukkassen, Dag dan Annette Meidell. 13 Oktober 2003. Advanced Materials and Structures and their Fabrication Processes, edisi III. HiN: NarvikUniversity College. Mueler, Dieter H. October 2003. New Discovery in the Properties of Composites Reinforced with Natural Fibers. JOURNAL OF INDUSTRIAL TEXTILES, Vol. 33, No. 2. Sage Publications. Nanang, 2006, Penelitian Kekuatan Bending Dan Impak Komposit Serat Kenaf Tanpa Perlakuan Alkali Dengan Fraksi Volume Serat 10%, 15% dan 20% Dengan Matrik Poliester. Saprudin, 2004, Penelitian Kekuatan Bending dan Impak Komposit Serat Kenaf Tanpa Perlakuan Alkali Dengan Fraksi Volume Serat 30% dan 40%. Surdia, 1992, Pengetahuan Bahan Teknik, FT, Pradnaya Paramita, Jakarta. Van Vlack, 2005, Ilmu dan Teknologi Bahan, Erlangga Jakarta. http://www.kemahasiswaan.its.ac.id.pdf : 15 Januari 2008 http://www.iptek.net.id/ind/?mnu=8&ch=jsti&id=115 : 20 Agustus 2008 http://www.gatra.com/2006-01-01/versi_cetak.php?id=91072 : 20 Agustus 2008

An American National Standard

Designation: D 638 – 02

Standard Test Method for

Tensile Properties of Plastics1 This standard is issued under the fixed designation D 638; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

1. Scope * 1.1 This test method covers the determination of the tensile properties of unreinforced and reinforced plastics in the form of standard dumbbell-shaped test specimens when tested under defined conditions of pretreatment, temperature, humidity, and testing machine speed. 1.2 This test method can be used for testing materials of any thickness up to 14 mm (0.55 in.). However, for testing specimens in the form of thin sheeting, including film less than 1.0 mm (0.04 in.) in thickness, Test Methods D 882 is the preferred test method. Materials with a thickness greater than 14 mm (0.55 in.) must be reduced by machining. 1.3 This test method includes the option of determining Poisson’s ratio at room temperature.

2. Referenced Documents 2.1 ASTM Standards: D 229 Test Methods for Rigid Sheet and Plate Materials Used for Electrical Insulation2 D 412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension3 D 618 Practice for Conditioning Plastics for Testing4 D 651 Test Method for Tensile Strength of Molded Electrical Insulating Materials5 D 882 Test Methods for Tensile Properties of Thin Plastic Sheeting4 D 883 Terminology Relating to Plastics4 D 1822 Test Method for Tensile-Impact Energy to Break Plastics and Electrical Insulating Materials4 D 3039/D 3039M Test Method for Tensile Properties of Polymer Matrix Composite Materials6 D 4000 Classification System for Specifying Plastic Materials7 D 4066 Classification System for Nylon Injection and Extrusion Materials7 D 5947 Test Methods for Physical Dimensions of Solid Plastic Specimens8 E 4 Practices for Force Verification of Testing Machines9 E 83 Practice for Verification and Classification of Extensometer9 E 132 Test Method for Poisson’s Ratio at Room Temperature9 E 691 Practice for Conducting an Interlaboratory Study to

NOTE 1—This test method and ISO 527-1 are technically equivalent. NOTE 2—This test method is not intended to cover precise physical procedures. It is recognized that the constant rate of crosshead movement type of test leaves much to be desired from a theoretical standpoint, that wide differences may exist between rate of crosshead movement and rate of strain between gage marks on the specimen, and that the testing speeds specified disguise important effects characteristic of materials in the plastic state. Further, it is realized that variations in the thicknesses of test specimens, which are permitted by these procedures, produce variations in the surface-volume ratios of such specimens, and that these variations may influence the test results. Hence, where directly comparable results are desired, all samples should be of equal thickness. Special additional tests should be used where more precise physical data are needed. NOTE 3—This test method may be used for testing phenolic molded resin or laminated materials. However, where these materials are used as electrical insulation, such materials should be tested in accordance with Test Methods D 229 and Test Method D 651. NOTE 4—For tensile properties of resin-matrix composites reinforced with oriented continuous or discontinuous high modulus >20-GPa (>3.0 3 106-psi) fibers, tests shall be made in accordance with Test Method D 3039/D 3039M.

1.4 Test data obtained by this test method are relevant and appropriate for use in engineering design. 1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

2

Annual Book of ASTM Standards, Vol 10.01. Annual Book of ASTM Standards, Vol 09.01. 4 Annual Book of ASTM Standards, Vol 08.01. 5 Discontinued; see 1994 Annual Book of ASTM Standards, Vol 10.01. 6 Annual Book of ASTM Standards, Vol 15.03. 7 Annual Book of ASTM Standards, Vol 08.02. 8 Annual Book of ASTM Standards, Vol 08.03. 9 Annual Book of ASTM Standards, Vol 03.01. 3

1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties. Current edition approved April 10, 2002. Published June 2002. Originally published as D 638 – 41 T. Last previous edition D 638 – 01.

*A Summary of Changes section appears at the end of this standard. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

1

D 638 Determine the Precision of a Test Method10 2.2 ISO Standard: ISO 527-1 Determination of Tensile Properties11

modulus of the usually defined type. Such a constant is useful if its arbitrary nature and dependence on time, temperature, and similar factors are realized.

4.4 Poisson’s Ratio—When uniaxial tensile force is applied to a solid, the solid stretches in the direction of the applied force (axially), but it also contracts in both dimensions lateral to the applied force. If the solid is homogeneous and isotropic, and the material remains elastic under the action of the applied force, the lateral strain bears a constant relationship to the axial strain. This constant, called Poisson’s ratio, is defined as the negative ratio of the transverse (negative) to axial strain under uniaxial stress. 4.4.1 Poisson’s ratio is used for the design of structures in which all dimensional changes resulting from the application of force need to be taken into account and in the application of the generalized theory of elasticity to structural analysis.

3. Terminology 3.1 Definitions—Definitions of terms applying to this test method appear in Terminology D 883 and Annex A2. 4. Significance and Use 4.1 This test method is designed to produce tensile property data for the control and specification of plastic materials. These data are also useful for qualitative characterization and for research and development. For many materials, there may be a specification that requires the use of this test method, but with some procedural modifications that take precedence when adhering to the specification. Therefore, it is advisable to refer to that material specification before using this test method. Table 1 in Classification D 4000 lists the ASTM materials standards that currently exist. 4.2 Tensile properties may vary with specimen preparation and with speed and environment of testing. Consequently, where precise comparative results are desired, these factors must be carefully controlled. 4.2.1 It is realized that a material cannot be tested without also testing the method of preparation of that material. Hence, when comparative tests of materials per se are desired, the greatest care must be exercised to ensure that all samples are prepared in exactly the same way, unless the test is to include the effects of sample preparation. Similarly, for referee purposes or comparisons within any given series of specimens, care must be taken to secure the maximum degree of uniformity in details of preparation, treatment, and handling. 4.3 Tensile properties may provide useful data for plastics engineering design purposes. However, because of the high degree of sensitivity exhibited by many plastics to rate of straining and environmental conditions, data obtained by this test method cannot be considered valid for applications involving load-time scales or environments widely different from those of this test method. In cases of such dissimilarity, no reliable estimation of the limit of usefulness can be made for most plastics. This sensitivity to rate of straining and environment necessitates testing over a broad load-time scale (including impact and creep) and range of environmental conditions if tensile properties are to suffice for engineering design purposes.

NOTE 6—The accuracy of the determination of Poisson’s ratio is usually limited by the accuracy of the transverse strain measurements because the percentage errors in these measurements are usually greater than in the axial strain measurements. Since a ratio rather than an absolute quantity is measured, it is only necessary to know accurately the relative value of the calibration factors of the extensometers. Also, in general, the value of the applied loads need not be known accurately.

5. Apparatus 5.1 Testing Machine—A testing machine of the constantrate-of-crosshead-movement type and comprising essentially the following: 5.1.1 Fixed Member—A fixed or essentially stationary member carrying one grip. 5.1.2 Movable Member—A movable member carrying a second grip. 5.1.3 Grips—Grips for holding the test specimen between the fixed member and the movable member of the testing machine can be either the fixed or self-aligning type. 5.1.3.1 Fixed grips are rigidly attached to the fixed and movable members of the testing machine. When this type of grip is used extreme care should be taken to ensure that the test specimen is inserted and clamped so that the long axis of the test specimen coincides with the direction of pull through the center line of the grip assembly. 5.1.3.2 Self-aligning grips are attached to the fixed and movable members of the testing machine in such a manner that they will move freely into alignment as soon as any load is applied so that the long axis of the test specimen will coincide with the direction of the applied pull through the center line of the grip assembly. The specimens should be aligned as perfectly as possible with the direction of pull so that no rotary motion that may induce slippage will occur in the grips; there is a limit to the amount of misalignment self-aligning grips will accommodate. 5.1.3.3 The test specimen shall be held in such a way that slippage relative to the grips is prevented insofar as possible. Grip surfaces that are deeply scored or serrated with a pattern similar to those of a coarse single-cut file, serrations about 2.4 mm (0.09 in.) apart and about 1.6 mm (0.06 in.) deep, have been found satisfactory for most thermoplastics. Finer serrations have been found to be more satisfactory for harder plastics, such as the thermosetting materials. The serrations

NOTE 5—Since the existence of a true elastic limit in plastics (as in many other organic materials and in many metals) is debatable, the propriety of applying the term “elastic modulus” in its quoted, generally accepted definition to describe the “stiffness” or “rigidity” of a plastic has been seriously questioned. The exact stress-strain characteristics of plastic materials are highly dependent on such factors as rate of application of stress, temperature, previous history of specimen, etc. However, stressstrain curves for plastics, determined as described in this test method, almost always show a linear region at low stresses, and a straight line drawn tangent to this portion of the curve permits calculation of an elastic

10

Annual Book of ASTM Standards, Vol 14.02. Available from American National Standards Institute, 25 W. 43rd St., 4th Floor, New York, NY 10036. 11

2

D 638 ments meets this requirement. 5.2.2 Low-Extension Measurements—For elongation-atyield and low-extension measurements (nominally 20 % or less), the same above extensometer, attenuated to 20 % extension, may be used. In any case, the extensometer system must meet at least Class C (Practice E 83) requirements, which include a fixed strain error of 0.001 strain or 61.0 % of the indicated strain, whichever is greater. 5.2.3 High-Extension Measurements—For making measurements at elongations greater than 20 %, measuring techniques with error no greater than 610 % of the measured value are acceptable. 5.2.4 Poisson’s Ratio—Bi-axial extensometer or axial and transverse extensometers capable of recording axial strain and transverse strain simultaneously. The extensometers shall be capable of measuring the change in strains with an accuracy of 1 % of the relevant value or better.

should be kept clean and sharp. Breaking in the grips may occur at times, even when deep serrations or abraded specimen surfaces are used; other techniques must be used in these cases. Other techniques that have been found useful, particularly with smooth-faced grips, are abrading that portion of the surface of the specimen that will be in the grips, and interposing thin pieces of abrasive cloth, abrasive paper, or plastic, or rubbercoated fabric, commonly called hospital sheeting, between the specimen and the grip surface. No. 80 double-sided abrasive paper has been found effective in many cases. An open-mesh fabric, in which the threads are coated with abrasive, has also been effective. Reducing the cross-sectional area of the specimen may also be effective. The use of special types of grips is sometimes necessary to eliminate slippage and breakage in the grips. 5.1.4 Drive Mechanism—A drive mechanism for imparting to the movable member a uniform, controlled velocity with respect to the stationary member, with this velocity to be regulated as specified in Section 8. 5.1.5 Load Indicator—A suitable load-indicating mechanism capable of showing the total tensile load carried by the test specimen when held by the grips. This mechanism shall be essentially free of inertia lag at the specified rate of testing and shall indicate the load with an accuracy of 61 % of the indicated value, or better. The accuracy of the testing machine shall be verified in accordance with Practices E 4.

NOTE 8—Strain gages can be used as an alternative method to measure axial and transverse strain; however, proper techniques for mounting strain gages are crucial to obtaining accurate data. Consult strain gage suppliers for instruction and training in these special techniques.

5.3 Micrometers—Suitable micrometers for measuring the width and thickness of the test specimen to an incremental discrimination of at least 0.025 mm (0.001 in.) should be used. All width and thickness measurements of rigid and semirigid plastics may be measured with a hand micrometer with ratchet. A suitable instrument for measuring the thickness of nonrigid test specimens shall have: (1) a contact measuring pressure of 25 6 2.5 kPa (3.6 6 0.36 psi), (2) a movable circular contact foot 6.35 6 0.025 mm (0.250 6 0.001 in.) in diameter, and (3) a lower fixed anvil large enough to extend beyond the contact foot in all directions and being parallel to the contact foot within 0.005 mm (0.0002 in.) over the entire foot area. Flatness of the foot and anvil shall conform to Test Method D 5947. 5.3.1 An optional instrument equipped with a circular contact foot 15.88 6 0.08 mm (0.625 6 0.003 in.) in diameter is recommended for thickness measuring of process samples or larger specimens at least 15.88 mm in minimum width.

NOTE 7—Experience has shown that many testing machines now in use are incapable of maintaining accuracy for as long as the periods between inspection recommended in Practices E 4. Hence, it is recommended that each machine be studied individually and verified as often as may be found necessary. It frequently will be necessary to perform this function daily.

5.1.6 The fixed member, movable member, drive mechanism, and grips shall be constructed of such materials and in such proportions that the total elastic longitudinal strain of the system constituted by these parts does not exceed 1 % of the total longitudinal strain between the two gage marks on the test specimen at any time during the test and at any load up to the rated capacity of the machine. 5.2 Extension Indicator (extensometer)—A suitable instrument shall be used for determining the distance between two designated points within the gage length of the test specimen as the specimen is stretched. For referee purposes, the extensometer must be set at the full gage length of the specimen, as shown in Fig. 1. It is desirable, but not essential, that this instrument automatically record this distance, or any change in it, as a function of the load on the test specimen or of the elapsed time from the start of the test, or both. If only the latter is obtained, load-time data must also be taken. This instrument shall be essentially free of inertia at the specified speed of testing. Extensometers shall be classified and their calibration periodically verified in accordance with Practice E 83. 5.2.1 Modulus-of-Elasticity Measurements—For modulusof-elasticity measurements, an extensometer with a maximum strain error of 0.0002 mm/mm (in./in.) that automatically and continuously records shall be used. An extensometer classified by Practice E 83 as fulfilling the requirements of a B-2 classification within the range of use for modulus measure-

6. Test Specimens 6.1 Sheet, Plate, and Molded Plastics: 6.1.1 Rigid and Semirigid Plastics—The test specimen shall conform to the dimensions shown in Fig. 1. The Type I specimen is the preferred specimen and shall be used where sufficient material having a thickness of 7 mm (0.28 in.) or less is available. The Type II specimen may be used when a material does not break in the narrow section with the preferred Type I specimen. The Type V specimen shall be used where only limited material having a thickness of 4 mm (0.16 in.) or less is available for evaluation, or where a large number of specimens are to be exposed in a limited space (thermal and environmental stability tests, etc.). The Type IV specimen should be used when direct comparisons are required between materials in different rigidity cases (that is, nonrigid and semirigid). The Type III specimen must be used for all materials with a thickness of greater than 7 mm (0.28 in.) but not more than 14 mm (0.55 in.). 6.1.2 Nonrigid Plastics—The test specimen shall conform to the dimensions shown in Fig. 1. The Type IV specimen shall 3

D 638

Specimen Dimensions for Thickness, T, mm (in.)A 7 (0.28) or under

Over 7 to 14 (0.28 to 0.55), incl

Dimensions (see drawings)

W—Width of narrow sectionE,F L—Length of narrow section WO—Width overall, minG WO—Width overall, minG LO—Length overall, minH G—Gage lengthI G—Gage lengthI D—Distance between grips R—Radius of fillet RO—Outer radius (Type IV)

4 (0.16) or under

Type I

Type II

Type III

Type IVB

Type VC,D

13 (0.50) 57 (2.25) 19 (0.75) ... 165 (6.5) 50 (2.00) ... 115 (4.5) 76 (3.00) ...

6 (0.25) 57 (2.25) 19 (0.75) ... 183 (7.2) 50 (2.00) ... 135 (5.3) 76 (3.00) ...

19 (0.75) 57 (2.25) 29 (1.13) ... 246 (9.7) 50 (2.00) ... 115 (4.5) 76 (3.00) ...

6 (0.25) 33 (1.30) 19 (0.75) ... 115 (4.5) ... 25 (1.00) 65 (2.5)J 14 (0.56) 25 (1.00)

3.18 (0.125) 9.53 (0.375) ... 9.53 (0.375) 63.5 (2.5) 7.62 (0.300) ... 25.4 (1.0) 12.7 (0.5) ...

Tolerances 60.5 (60.02)B,C 60.5 (60.02)C + 6.4 ( + 0.25) + 3.18 ( + 0.125) no max (no max) 60.25 (60.010)C 60.13 (60.005) 65 (60.2) 61 (60.04)C 61 (60.04)

A Thickness, T, shall be 3.26 0.4 mm (0.13 6 0.02 in.) for all types of molded specimens, and for other Types I and II specimens where possible. If specimens are machined from sheets or plates, thickness, T, may be the thickness of the sheet or plate provided this does not exceed the range stated for the intended specimen type. For sheets of nominal thickness greater than 14 mm (0.55 in.) the specimens shall be machined to 14 6 0.4 mm (0.55 6 0.02 in.) in thickness, for use with the Type III specimen. For sheets of nominal thickness between 14 and 51 mm (0.55 and 2 in.) approximately equal amounts shall be machined from each surface. For thicker sheets both surfaces of the specimen shall be machined, and the location of the specimen with reference to the original thickness of the sheet shall be noted. Tolerances on thickness less than 14 mm (0.55 in.) shall be those standard for the grade of material tested. B For the Type IV specimen, the internal width of the narrow section of the die shall be 6.00 6 0.05 mm (0.2506 0.002 in.). The dimensions are essentially those of Die C in Test Methods D 412. C The Type V specimen shall be machined or die cut to the dimensions shown, or molded in a mold whose cavity has these dimensions. The dimensions shall be: W = 3.18 6 0.03 mm (0.125 6 0.001 in.), L = 9.53 6 0.08 mm (0.375 6 0.003 in.), G = 7.62 6 0.02 mm (0.300 6 0.001 in.), and R = 12.7 6 0.08 mm (0.500 6 0.003 in.). The other tolerances are those in the table. D Supporting data on the introduction of the L specimen of Test Method D 1822 as the Type V specimen are available from ASTM Headquarters. Request RR:D20-1038. E The width at the center Wc shall be +0.00 mm, −0.10 mm ( +0.000 in., −0.004 in.) compared with width W at other parts of the reduced section. Any reduction in W at the center shall be gradual, equally on each side so that no abrupt changes in dimension result. F For molded specimens, a draft of not over 0.13 mm (0.005 in.) may be allowed for either Type I or II specimens 3.2 mm (0.13 in.) in thickness, and this should be taken into account when calculating width of the specimen. Thus a typical section of a molded Type I specimen, having the maximum allowable draft, could be as follows: G Overall widths greater than the minimum indicated may be desirable for some materials in order to avoid breaking in the grips. H Overall lengths greater than the minimum indicated may be desirable either to avoid breaking in the grips or to satisfy special test requirements. I Test marks or initial extensometer span. J When self-tightening grips are used, for highly extensible polymers, the distance between grips will depend upon the types of grips used and may not be critical if maintained uniform once chosen.

FIG. 1 Tension Test Specimens for Sheet, Plate, and Molded Plastics

be used for testing nonrigid plastics with a thickness of 4 mm (0.16 in.) or less. The Type III specimen must be used for all materials with a thickness greater than 7 mm (0.28 in.) but not more than 14 mm (0.55 in.).

6.1.3 Reinforced Composites—The test specimen for reinforced composites, including highly orthotropic laminates, shall conform to the dimensions of the Type I specimen shown in Fig. 1. 4

D 638 6.1.4 Preparation—Test specimens shall be prepared by machining operations, or die cutting, from materials in sheet, plate, slab, or similar form. Materials thicker than 14 mm (0.55 in.) must be machined to 14 mm (0.55 in.) for use as Type III specimens. Specimens can also be prepared by molding the material to be tested. NOTE 9—Test results have shown that for some materials such as glass cloth, SMC, and BMC laminates, other specimen types should be considered to ensure breakage within the gage length of the specimen, as mandated by 7.3. NOTE 10—When preparing specimens from certain composite laminates such as woven roving, or glass cloth, care must be exercised in cutting the specimens parallel to the reinforcement. The reinforcement will be significantly weakened by cutting on a bias, resulting in lower laminate properties, unless testing of specimens in a direction other than parallel with the reinforcement constitutes a variable being studied. NOTE 11—Specimens prepared by injection molding may have different tensile properties than specimens prepared by machining or die-cutting because of the orientation induced. This effect may be more pronounced in specimens with narrow sections.

6.2 Rigid Tubes—The test specimen for rigid tubes shall be as shown in Fig. 2. The length, L, shall be as shown in the table in Fig. 2. A groove shall be machined around the outside of the specimen at the center of its length so that the wall section after machining shall be 60 % of the original nominal wall thickness. This groove shall consist of a straight section 57.2 mm (2.25 in.) in length with a radius of 76 mm (3 in.) at each end joining it to the outside diameter. Steel or brass plugs having diameters such that they will fit snugly inside the tube and having a length equal to the full jaw length plus 25 mm (1 in.) shall be placed in the ends of the specimens to prevent crushing. They can be located conveniently in the tube by separating and supporting them on a threaded metal rod. Details of plugs and test assembly are shown in Fig. 2. 6.3 Rigid Rods—The test specimen for rigid rods shall be as shown in Fig. 3. The length, L, shall be as shown in the table in Fig. 3. A groove shall be machined around the specimen at the center of its length so that the diameter of the machined portion shall be 60 % of the original nominal diameter. This groove shall consist of a straight section 57.2 mm (2.25 in.) in length with a radius of 76 mm (3 in.) at each end joining it to the outside diameter. 6.4 All surfaces of the specimen shall be free of visible flaws, scratches, or imperfections. Marks left by coarse machining operations shall be carefully removed with a fine file or abrasive, and the filed surfaces shall then be smoothed with abrasive paper (No. 00 or finer). The finishing sanding strokes shall be made in a direction parallel to the long axis of the test specimen. All flash shall be removed from a molded specimen, taking great care not to disturb the molded surfaces. In machining a specimen, undercuts that would exceed the dimensional tolerances shown in Fig. 1 shall be scrupulously avoided. Care shall also be taken to avoid other common machining errors. 6.5 If it is necessary to place gage marks on the specimen, this shall be done with a wax crayon or India ink that will not affect the material being tested. Gage marks shall not be scratched, punched, or impressed on the specimen. 6.6 When testing materials that are suspected of anisotropy,

DIMENSIONS OF ROD SPECIMENS Nominal Diam- Length of Radial eter Sections, 2R.S.

Standard Length, L, of Total Calculated Specimen to Be Used Minimum for 89-mm (31⁄2-in.) Length of Specimen JawsA mm (in.)

3.2 ( ⁄ ) 4.7 (1⁄16) 6.4 (1⁄4) 9.5 (3⁄8) 12.7 (1⁄2) 15.9 (5⁄8) 19.0 (3⁄4) 22.2 (7⁄8) 25.4 (1) 31.8 (11⁄4) 38.1 (11⁄2) 42.5 (13⁄4) 50.8 (2) 18

19.6 24.0 27.7 33.9 39.0 43.5 47.6 51.5 54.7 60.9 66.4 71.4 76.0

(0.773) (0.946) (1.091) (1.333) (1.536) (1.714) (1.873) (2.019) (2.154) (2.398) (2.615) (2.812) (2.993)

356 361 364 370 376 380 384 388 391 398 403 408 412

(14.02) (14.20) (14.34) (14.58) (14.79) (14.96) (15.12) (15.27) (15.40) (15.65) (15.87) (16.06) (16.24)

381 381 381 381 400 400 400 400 419 419 419 419 432

(15) (15) (15) (15) (15.75) (15.75) (15.75) (15.75) (16.5) (16.5) (16.5) (16.5) (17)

A For other jaws greater than 89 mm (3.5 in.), the standard length shall be increased by twice the length of the jaws minus 178 mm (7 in.). The standard length permits a slippage of approximately 6.4 to 12.7 mm (0.25 to 0.50 in.) in each jaw while maintaining the maximum length of the jaw grip.

FIG. 3 Diagram Showing Location of Rod Tension Test Specimen in Testing Machine

duplicate sets of test specimens shall be prepared, having their long axes respectively parallel with, and normal to, the suspected direction of anisotropy. 7. Number of Test Specimens 7.1 Test at least five specimens for each sample in the case of isotropic materials. 5

D 638 a variable to be studied. NOTE 12—Before testing, all transparent specimens should be inspected in a polariscope. Those which show atypical or concentrated strain patterns should be rejected, unless the effects of these residual strains constitute a variable to be studied.

8. Speed of Testing 8.1 Speed of testing shall be the relative rate of motion of the grips or test fixtures during the test. The rate of motion of the driven grip or fixture when the testing machine is running idle may be used, if it can be shown that the resulting speed of testing is within the limits of variation allowed. 8.2 Choose the speed of testing from Table 1. Determine this chosen speed of testing by the specification for the material being tested, or by agreement between those concerned. When the speed is not specified, use the lowest speed shown in Table 1 for the specimen geometry being used, which gives rupture within 1⁄2 to 5-min testing time. 8.3 Modulus determinations may be made at the speed selected for the other tensile properties when the recorder response and resolution are adequate. 8.4 Poisson’s ratio determinations shall be made at the same speed selected for modulus determinations. 9. Conditioning 9.1 Conditioning—Condition the test specimens at 23 6 2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity for not less than 40 h prior to test in accordance with Procedure A of Practice D 618, unless otherwise specified by contract or the relevant ASTM material specification. Reference pre-test conditioning, to settle disagreements, shall apply tolerances of 61°C (1.8°F) and 62 % relative humidity. 9.2 Test Conditions—Conduct the tests at 23 6 2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity, unless otherwise specified by contract or the relevant ASTM material specification. Reference testing conditions, to settle disagreements,

DIMENSIONS OF TUBE SPECIMENS Nominal Wall Thickness

Length of Radial Total Calculated Sections, Minimum 2R.S. Length of Specimen

Standard Length, L, of Specimen to Be Used for 89-mm (3.5-in.) JawsA

mm (in.) 0.79 (1⁄32) 1.2 (3⁄64) 1.6 (1⁄16) 2.4 (3⁄32) 3.2 (1⁄8) 4.8 (3⁄16) 6.4 (1⁄4) 7.9 (5⁄16) 9.5 (3⁄8) 11.1 (7⁄16) 12.7 (1⁄2)

13.9 17.0 19.6 24.0 27.7 33.9 39.0 43.5 47.6 51.3 54.7

(0.547) (0.670) (0.773) (0.946) (1.091) (1.333) (1.536) (1.714) (1.873) (2.019) (2.154)

350 354 356 361 364 370 376 380 384 388 391

(13.80) (13.92) (14.02) (14.20) (14.34) (14.58) (14.79) (14.96) (15.12) (15.27) (15.40)

381 381 381 381 381 381 400 400 400 400 419

TABLE 1 Designations for Speed of TestingA

(15) (15) (15) (15) (15) (15) (15.75) (15.75) (15.75) (15.75) (16.5)

Classification

B

Rigid and Semirigid

Specimen Type

I, II, III rods and tubes

IV

A For other jaws greater than 89 mm (3.5 in.), the standard length shall be increased by twice the length of the jaws minus 178 mm (7 in.). The standard length permits a slippage of approximately 6.4 to 12.7 mm (0.25 to 0.50 in.) in each jaw while maintaining the maximum length of the jaw grip.

V

Nonrigid

FIG. 2 Diagram Showing Location of Tube Tension Test Specimens in Testing Machine

III IV

7.2 Test ten specimens, five normal to, and five parallel with, the principle axis of anisotropy, for each sample in the case of anisotropic materials. 7.3 Discard specimens that break at some flaw, or that break outside of the narrow cross-sectional test section (Fig. 1, dimension “L”), and make retests, unless such flaws constitute

Speed of Testing, mm/min (in./min)

5 (0.2) 6 25 % 50 (2) 6 10 % 500 (20) 6 10 % 5 (0.2) 6 25 % 50 (2) 6 10 % 500 (20) 6 10 % 1 (0.05) 6 25 % 10 (0.5) 6 25 % 100 (5)6 25 % 50 (2) 6 10 % 500 (20) 6 10 % 50 (2) 6 10 % 500 (20) 6 10 %

Nominal StrainC Rate at Start of Test, mm/mm· min (in./in.·min) 0.1 1 10 0.15 1.5 15 0.1 1 10 1 10 1.5 15

A Select the lowest speed that produces rupture in 1⁄2 to 5 min for the specimen geometry being used (see 8.2). B See Terminology D 883 for definitions. C The initial rate of straining cannot be calculated exactly for dumbbell-shaped specimens because of extension, both in the reduced section outside the gage length and in the fillets. This initial strain rate can be measured from the initial slope of the tensile strain-versus-time diagram.

6

D 638 shall apply tolerances of 61°C (1.8°F) and 62 % relative humidity.

TABLE 4 Elongation at Yield, %, for Eight Laboratories, Three Materials

10. Procedure 10.1 Measure the width and thickness of rigid flat specimens (Fig. 1) with a suitable micrometer to the nearest 0.025 mm (0.001 in.) at several points along their narrow sections. Measure the thickness of nonrigid specimens (produced by a Type IV die) in the same manner with the required dial micrometer. Take the width of this specimen as the distance between the cutting edges of the die in the narrow section. Measure the diameter of rod specimens, and the inside and outside diameters of tube specimens, to the nearest 0.025 mm (0.001 in.) at a minimum of two points 90° apart; make these measurements along the groove for specimens so constructed. Use plugs in testing tube specimens, as shown in Fig. 2.

Cellulose acetate butyrate Acrylic Polypropylene

Polypropylene Cellulose acetate butyrate Acrylic Glass-reinforced nylon Glass-reinforced polyester

Sr

SR

Ir

IR

0.210 0.246 0.481 1.17 1.39

0.0089 0.0179 0.0179 0.0537 0.0894

0.071 0.035 0.063 0.217 0.266

0.025 0.051 0.051 0.152 0.253

0.201 0.144 0.144 0.614 0.753

10.3.1 Poisson’s Ratio Determination: 10.3.1.1 When Poisson’s ratio is determined, the speed of testing and the load range at which it is determined shall be the same as those used for modulus of elasticity. 10.3.1.2 Attach the transverse strain measuring device. The transverse strain measuring device must continuously measure the strain simultaneously with the axial strain measuring device. TABLE 3 Tensile Stress at Yield, 103 psi, for Eight Laboratories, Three Materials Sr

SR

Ir

IR

3.63 5.01 10.4

0.022 0.058 0.067

0.161 0.227 0.317

0.062 0.164 0.190

0.456 0.642 0.897

Ir

IR

0.62 0.55 5.86

0.76 0.59 1.27

1.75 1.56 16.5

11. Calculation 11.1 Toe compensation shall be made in accordance with Annex A1, unless it can be shown that the toe region of the curve is not due to the take-up of slack, seating of the specimen, or other artifact, but rather is an authentic material response. 11.2 Tensile Strength—Calculate the tensile strength by dividing the maximum load in newtons (or pounds-force) by the original minimum cross-sectional area of the specimen in square metres (or square inches). Express the result in pascals (or pounds-force per square inch) and report it to three significant figures as tensile strength at yield or tensile strength at break, whichever term is applicable. When a nominal yield or break load less than the maximum is present and applicable, it may be desirable also to calculate, in a similar manner, the corresponding tensile stress at yield or tensile stress at break and report it to three significant figures (see Note A2.8). 11.3 Percent Elongation—If the specimen gives a yield load that is larger than the load at break, calculate percent elongation at yield. Otherwise, calculate percent elongation at break. Do this by reading the extension (change in gage length) at the moment the applicable load is reached. Divide that extension by the original gage length and multiply by 100. Report percent elongation at yield or percent elongation at break to two significant figures. When a yield or breaking load less than the maximum is present and of interest, it is desirable to calculate and report both percent elongation at yield and percent elongation at break (see Note A2.2). 11.4 Modulus of Elasticity—Calculate the modulus of elasticity by extending the initial linear portion of the loadextension curve and dividing the difference in stress corresponding to any segment of section on this straight line by the corresponding difference in strain. All elastic modulus values shall be computed using the average initial cross-sectional area

NOTE 13—Modulus of materials is determined from the slope of the linear portion of the stress-strain curve. For most plastics, this linear portion is very small, occurs very rapidly, and must be recorded automatically. The change in jaw separation is never to be used for calculating modulus or elongation.

Mean

SR

0.27 0.21 0.45

NOTE 14—If it is desired to measure both modulus and failure properties (yield or break, or both), it may be necessary, in the case of highly extensible materials, to run two independent tests. The high magnification extensometer normally used to determine properties up to the yield point may not be suitable for tests involving high extensibility. If allowed to remain attached to the specimen, the extensometer could be permanently damaged. A broad-range incremental extensometer or hand-rule technique may be needed when such materials are taken to rupture.

10.2 Place the specimen in the grips of the testing machine, taking care to align the long axis of the specimen and the grips with an imaginary line joining the points of attachment of the grips to the machine. The distance between the ends of the gripping surfaces, when using flat specimens, shall be as indicated in Fig. 1. On tube and rod specimens, the location for the grips shall be as shown in Fig. 2 and Fig. 3. Tighten the grips evenly and firmly to the degree necessary to prevent slippage of the specimen during the test, but not to the point where the specimen would be crushed. 10.3 Attach the extension indicator. When modulus is being determined, a Class B-2 or better extensometer is required (see 5.2.1).

Polypropylene Cellulose acetate butyrate Acrylic

Sr

3.65 4.89 8.79

10.3.1.3 Make simultaneous measurements of load and strain and record the data. The precision of the value of Poisson’s ratio will depend on the number of data points of axial and transverse strain taken. 10.4 Set the speed of testing at the proper rate as required in Section 8, and start the machine. 10.5 Record the load-extension curve of the specimen. 10.6 Record the load and extension at the yield point (if one exists) and the load and extension at the moment of rupture.

TABLE 2 Modulus, 106 psi, for Eight Laboratories, Five Materials Mean

Mean

7

D 638

FIG. 4 Plot of Strains Versus Load for Determination of Poisson’s Ratio

of the test specimens in the calculations. The result shall be expressed in pascals (pounds-force per square inch) and reported to three significant figures. 11.5 Secant Modulus—At a designated strain, this shall be calculated by dividing the corresponding stress (nominal) by the designated strain. Elastic modulus values are preferable and shall be calculated whenever possible. However, for materials where no proportionality is evident, the secant value shall be calculated. Draw the tangent as directed in A1.3 and Fig. A1.2, and mark off the designated strain from the yield point where the tangent line goes through zero stress. The stress to be used in the calculation is then determined by dividing the loadextension curve by the original average cross-sectional area of the specimen. 11.6 Poisson’s Ratio—The axial strain, ea, indicated by the axial extensometer, and the transverse strain, e, indicated by the transverse extensometers, are plotted against the applied load, P, as shown in Fig. 4. A straight line is drawn through each set of points, and the slopes, dea / dP and det / dP, of these lines are determined. Poisson’s ratio, µ, is then calculated as follows: µ 5 2~det / dP!/~dea / dP!

where: s = estimated standard deviation, X = value of single observation, n = number of observations, and X¯ = arithmetic mean of the set of observations. 11.9 See Annex A1 for information on toe compensation. TABLE 5 Tensile Strength at Break, 103 psi, for Eight Laboratories, Five MaterialsA Polypropylene Cellulose acetate butyrate Acrylic Glass-reinforced polyester Glass-reinforced nylon

SR

Ir

IR

1.54 0.058 0.452 0.233 0.277

1.65 0.180 0.751 0.437 0.698

4.37 0.164 1.27 0.659 0.784

4.66 0.509 2.13 1.24 1.98

TABLE 6 Elongation at Break, %, for Eight Laboratories, Five MaterialsA

(1)

Glass-reinforced polyester Glass-reinforced nylon Acrylic Cellulose acetate butyrate Polypropylene

Mean

Sr

SR

Ir

IR

3.68 3.87 13.2 14.1 293.0

0.20 0.10 2.05 1.87 50.9

2.33 2.13 3.65 6.62 119.0

0.570 0.283 5.80 5.29 144.0

6.59 6.03 10.3 18.7 337.0

A Tensile strength and elongation at break values obtained for unreinforced propylene plastics generally are highly variable due to inconsistencies in necking or “drawing” of the center section of the test bar. Since tensile strength and elongation at yield are more reproducible and relate in most cases to the practical usefulness of a molded part, they are generally recommended for specification purposes.

(2)

11.6.1 The errors that may be introduced by drawing a straight line through the points can be reduced by applying the method of least squares. 11.7 For each series of tests, calculate the arithmetic mean of all values obtained and report it as the “average value” for the particular property in question. 11.8 Calculate the standard deviation (estimated) as follows and report it to two significant figures: s 5 =~ (X 2 2 nX¯ 2! / ~n 2 1!

Sr

2.97 4.82 9.09 20.8 23.6

A Tensile strength and elongation at break values obtained for unreinforced propylene plastics generally are highly variable due to inconsistencies in necking or “drawing” of the center section of the test bar. Since tensile strength and elongation at yield are more reproducible and relate in most cases to the practical usefulness of a molded part, they are generally recommended for specification purposes.

where: det = change in transverse strain, dea = change in axial strain, and dP = change in applied load; or µ 5 2~det! / ~dea!

Mean

12. Report 12.1 Report the following information: 12.1.1 Complete identification of the material tested, including type, source, manufacturer’s code numbers, form, principal dimensions, previous history, etc., 12.1.2 Method of preparing test specimens, 12.1.3 Type of test specimen and dimensions,

(3)

8

D 638 TABLE 7 Tensile Yield Strength, for Ten Laboratories, Eight Materials Material LDPE LDPE LLDPE LLDPE LLDPE LLDPE HDPE HDPE

Test Speed, in./min

Average

Sr

SR

r

R

20 20 20 20 20 20 2 2

1544 1894 1879 1791 2900 1730 4101 3523

52.4 53.1 74.2 49.2 55.5 63.9 196.1 175.9

64.0 61.2 99.9 75.8 87.9 96.0 371.9 478.0

146.6 148.7 207.8 137.9 155.4 178.9 549.1 492.4

179.3 171.3 279.7 212.3 246.1 268.7 1041.3 1338.5

TABLE 9 Tensile Break Strength, for Nine Laboratories, Six Materials

Values Expressed in psi Units Material LDPE LDPE LLDPE LLDPE LLDPE LLDPE

Test Speed, in./min

Average

Sr

SR

r

R

20 20 20 20 20 20

1592 1750 4379 2840 1679 2660

52.3 66.6 127.1 78.6 34.3 119.1

74.9 102.9 219.0 143.5 47.0 166.3

146.4 186.4 355.8 220.2 95.96 333.6

209.7 288.1 613.3 401.8 131.6 465.6

Values Expressed in psi Units

TABLE 10 Tensile Break Elongation, for Nine Laboratories, Six Materials

12.1.4 Conditioning procedure used, 12.1.5 Atmospheric conditions in test room, 12.1.6 Number of specimens tested, 12.1.7 Speed of testing, 12.1.8 Classification of extensometers used. A description of measuring technique and calculations employed instead of a minimum Class-C extensometer system, 12.1.9 Tensile strength at yield or break, average value, and standard deviation, 12.1.10 Tensile stress at yield or break, if applicable, average value, and standard deviation, 12.1.11 Percent elongation at yield or break, or both, as applicable, average value, and standard deviation, 12.1.12 Modulus of elasticity, average value, and standard deviation, 12.1.13 Date of test, and 12.1.14 Revision date of Test Method D 638.

Material LDPE LDPE LLDPE LLDPE LLDPE LLDPE

TABLE 8 Tensile Yield Elongation, for Eight Laboratories, Eight Materials

LDPE LDPE LLDPE LLDPE LLDPE LLDPE HDPE HDPE

Test Speed, in./min

Average

Sr

SR

r

R

20 20 20 20 20 20 2 2

17.0 14.6 15.7 16.6 11.7 15.2 9.27 9.63

1.26 1.02 1.37 1.59 1.27 1.27 1.40 1.23

3.16 2.38 2.85 3.30 2.88 2.59 2.84 2.75

3.52 2.86 3.85 4.46 3.56 3.55 3.91 3.45

8.84 6.67 7.97 9.24 8.08 7.25 7.94 7.71

Average

Sr

SR

r

R

20 20 20 20 20 20

567 569 890 64.4 803 782

31.5 61.5 25.7 6.68 25.7 41.6

59.5 89.2 113.8 11.7 104.4 96.7

88.2 172.3 71.9 18.7 71.9 116.6

166.6 249.7 318.7 32.6 292.5 270.8

Values Expressed in Percent Units

individual specimens were prepared at the laboratories that tested them. Each test result was the average of five individual determinations. Each laboratory obtained three test results for each material. Data from some laboratories could not be used for various reasons, and this is noted in each table. 13.1.2 In Tables 2-10, for the materials indicated, and for test results that derived from testing five specimens: 13.1.2.1 Sr is the within-laboratory standard deviation of the average; Ir = 2.83 Sr. (See 13.1.2.3 for application of Ir.) 13.1.2.2 SR is the between-laboratory standard deviation of the average; IR = 2.83 SR. (See 13.1.2.4 for application of IR.) 13.1.2.3 Repeatability—In comparing two test results for the same material, obtained by the same operator using the same equipment on the same day, those test results should be judged not equivalent if they differ by more than the Ir value for that material and condition. 13.1.2.4 Reproducibility—In comparing two test results for the same material, obtained by different operators using different equipment on different days, those test results should be judged not equivalent if they differ by more than the IR value for that material and condition. (This applies between different laboratories or between different equipment within the same laboratory.) 13.1.2.5 Any judgment in accordance with 13.1.2.3 and 13.1.2.4 will have an approximate 95 % (0.95) probability of being correct. 13.1.2.6 Other formulations may give somewhat different results. 13.1.2.7 For further information on the methodology used in this section, see Practice E 691. 13.1.2.8 The precision of this test method is very dependent upon the uniformity of specimen preparation, standard practices for which are covered in other documents. 13.2 Bias—There are no recognized standards on which to base an estimate of bias for this test method.

13. Precision and Bias 12 13.1 Precision—Tables 2-6 are based on a round-robin test conducted in 1984, involving five materials tested by eight laboratories using the Type I specimen, all of nominal 0.125-in. thickness. Each test result was based on five individual determinations. Each laboratory obtained two test results for each material.

Material

Test Speed, in./min

Values Expressed in Percent Units

13.1.1 Tables 7-10 are based on a round-robin test conducted by the polyolefin subcommittee in 1988, involving eight polyethylene materials tested in ten laboratories. For each material, all samples were molded at one source, but the 12 Supporting data are available from ASTM Headquarters. Request RR:D201125 for the 1984 round robin and RR:D20-1170 for the 1988 round robin.

9

D 638 14. Keywords 14.1 modulus of elasticity; percent elongation; plastics; tensile properties; tensile strength

ANNEXES (Mandatory Information) A1. TOE COMPENSATION

A1.1 In a typical stress-strain curve (Fig. A1.1) there is a toe region, AC, that does not represent a property of the material. It is an artifact caused by a takeup of slack and alignment or seating of the specimen. In order to obtain correct values of such parameters as modulus, strain, and offset yield point, this artifact must be compensated for to give the corrected zero point on the strain or extension axis.

elastic modulus can be determined by dividing the stress at any point along the line CD (or its extension) by the strain at the same point (measured from Point B, defined as zero-strain). A1.3 In the case of a material that does not exhibit any linear region (Fig. A1.2), the same kind of toe correction of the zero-strain point can be made by constructing a tangent to the maximum slope at the inflection point (H8). This is extended to intersect the strain axis at Point B8, the corrected zero-strain point. Using Point B8 as zero strain, the stress at any point (G8) on the curve can be divided by the strain at that point to obtain a secant modulus (slope of Line B8 G8). For those materials with no linear region, any attempt to use the tangent through the inflection point as a basis for determination of an offset yield point may result in unacceptable error.

A1.2 In the case of a material exhibiting a region of Hookean (linear) behavior (Fig. A1.1), a continuation of the linear (CD) region of the curve is constructed through the zero-stress axis. This intersection (B) is the corrected zerostrain point from which all extensions or strains must be measured, including the yield offset (BE), if applicable. The

NOTE 1—Some chart recorders plot the mirror image of this graph.

NOTE 1—Some chart recorders plot the mirror image of this graph.

FIG. A1.1 Material with Hookean Region

FIG. A1.2 Material with No Hookean Region

10

D 638 A2. DEFINITIONS OF TERMS AND SYMBOLS RELATING TO TENSION TESTING OF PLASTICS

A2.1 elastic limit—the greatest stress which a material is capable of sustaining without any permanent strain remaining upon complete release of the stress. It is expressed in force per unit area, usually pounds-force per square inch (megapascals). NOTE A2.1—Measured values of proportional limit and elastic limit vary greatly with the sensitivity and accuracy of the testing equipment, eccentricity of loading, the scale to which the stress-strain diagram is plotted, and other factors. Consequently, these values are usually replaced by yield strength.

A2.2 elongation—the increase in length produced in the gage length of the test specimen by a tensile load. It is expressed in units of length, usually inches (millimetres). (Also known as extension.) NOTE A2.2—Elongation and strain values are valid only in cases where uniformity of specimen behavior within the gage length is present. In the case of materials exhibiting necking phenomena, such values are only of qualitative utility after attainment of yield point. This is due to inability to ensure that necking will encompass the entire length between the gage marks prior to specimen failure.

FIG. A2.1 Offset Yield Strength

The stress at the point of intersection r is the “offset yield strength.” The specified value of the offset must be stated as a percent of the original gage length in conjunction with the strength value. Example: 0.1 % offset yield strength = ... MPa (psi), or yield strength at 0.1 % offset ... MPa (psi).

A2.3 gage length—the original length of that portion of the specimen over which strain or change in length is determined.

A2.7 percent elongation—the elongation of a test specimen expressed as a percent of the gage length.

A2.4 modulus of elasticity—the ratio of stress (nominal) to corresponding strain below the proportional limit of a material. It is expressed in force per unit area, usually megapascals (pounds-force per square inch). (Also known as elastic modulus or Young’s modulus).

A2.8 percent elongation at break and yield: A2.8.1 percent elongation at break the percent elongation at the moment of rupture of the test specimen. A2.8.2 percent elongation at yield the percent elongation at the moment the yield point (A2.21) is attained in the test specimen.

NOTE A2.3—The stress-strain relations of many plastics do not conform to Hooke’s law throughout the elastic range but deviate therefrom even at stresses well below the elastic limit. For such materials the slope of the tangent to the stress-strain curve at a low stress is usually taken as the modulus of elasticity. Since the existence of a true proportional limit in plastics is debatable, the propriety of applying the term “modulus of elasticity” to describe the stiffness or rigidity of a plastic has been seriously questioned. The exact stress-strain characteristics of plastic materials are very dependent on such factors as rate of stressing, temperature, previous specimen history, etc. However, such a value is useful if its arbitrary nature and dependence on time, temperature, and other factors are realized.

A2.9 percent reduction of area (nominal)—the difference between the original cross-sectional area measured at the point of rupture after breaking and after all retraction has ceased, expressed as a percent of the original area.

A2.5 necking—the localized reduction in cross section which may occur in a material under tensile stress.

A2.10 percent reduction of area (true)—the difference between the original cross-sectional area of the test specimen and the minimum cross-sectional area within the gage boundaries prevailing at the moment of rupture, expressed as a percentage of the original area.

A2.6 offset yield strength—the stress at which the strain exceeds by a specified amount (the offset) an extension of the initial proportional portion of the stress-strain curve. It is expressed in force per unit area, usually megapascals (poundsforce per square inch).

A2.11 proportional limit—the greatest stress which a material is capable of sustaining without any deviation from proportionality of stress to strain (Hooke’s law). It is expressed in force per unit area, usually megapascals (pounds-force per square inch).

NOTE A2.4—This measurement is useful for materials whose stressstrain curve in the yield range is of gradual curvature. The offset yield strength can be derived from a stress-strain curve as follows (Fig. A2.1):

A2.12 rate of loading—the change in tensile load carried by the specimen per unit time. It is expressed in force per unit time, usually newtons (pounds-force) per minute. The initial rate of loading can be calculated from the initial slope of the load versus time diagram.

On the strain axis lay off OM equal to the specified offset. Draw OA tangent to the initial straight-line portion of the stress-strain curve. Through M draw a line MN parallel to OA and locate the intersection of MN with the stress-strain curve.

A2.13 rate of straining—the change in tensile strain per unit time. It is expressed either as strain per unit time, usually 11

D 638 metres per metre (inches per inch) per minute, or percent elongation per unit time, usually percent elongation per minute. The initial rate of straining can be calculated from the initial slope of the tensile strain versus time diagram. NOTE A2.5—The initial rate of straining is synonymous with the rate of crosshead movement divided by the initial distance between crossheads only in a machine with constant rate of crosshead movement and when the specimen has a uniform original cross section, does not “neck down,” and does not slip in the jaws.

FIG. A2.2 Illustration of True Strain Equation

eT 5

A2.14 rate of stressing (nominal)—the change in tensile stress (nominal) per unit time. It is expressed in force per unit area per unit time, usually megapascals (pounds-force per square inch) per minute. The initial rate of stressing can be calculated from the initial slope of the tensile stress (nominal) versus time diagram.

* dL/L 5 ln L/L L

Lo

o

(A2.1)

where: dL = increment of elongation when the distance between the gage marks is L, Lo = original distance between gage marks, and L = distance between gage marks at any time. A2.21 yield point—the first point on the stress-strain curve at which an increase in strain occurs without an increase in stress (Fig. A2.2).

NOTE A2.6—The initial rate of stressing as determined in this manner has only limited physical significance. It does, however, roughly describe the average rate at which the initial stress (nominal) carried by the test specimen is applied. It is affected by the elasticity and flow characteristics of the materials being tested. At the yield point, the rate of stressing (true) may continue to have a positive value if the cross-sectional area is decreasing.

NOTE A2.9—Only materials whose stress-strain curves exhibit a point of zero slope may be considered as having a yield point. NOTE A2.10—Some materials exhibit a distinct “break” or discontinuity in the stress-strain curve in the elastic region. This break is not a yield point by definition. However, this point may prove useful for material characterization in some cases.

A2.15 secant modulus—the ratio of stress (nominal) to corresponding strain at any specified point on the stress-strain curve. It is expressed in force per unit area, usually megapascals (pounds-force per square inch), and reported together with the specified stress or strain.

A2.22 yield strength—the stress at which a material exhibits a specified limiting deviation from the proportionality of stress to strain. Unless otherwise specified, this stress will be the stress at the yield point and when expressed in relation to the tensile strength shall be designated either tensile strength at yield or tensile stress at yield as required in A2.17 (Fig. A2.3). (See offset yield strength.)

NOTE A2.7—This measurement is usually employed in place of modulus of elasticity in the case of materials whose stress-strain diagram does not demonstrate proportionality of stress to strain.

A2.16 strain—the ratio of the elongation to the gage length of the test specimen, that is, the change in length per unit of original length. It is expressed as a dimensionless ratio. A2.17 tensile strength (nominal)—the maximum tensile stress (nominal) sustained by the specimen during a tension test. When the maximum stress occurs at the yield point (A2.21), it shall be designated tensile strength at yield. When the maximum stress occurs at break, it shall be designated tensile strength at break.

A2.23 Symbols—The following symbols may be used for the above terms: Symbol W DW L Lo Lu DL A Ao DA Au

A2.18 tensile stress (nominal)—the tensile load per unit area of minimum original cross section, within the gage boundaries, carried by the test specimen at any given moment. It is expressed in force per unit area, usually megapascals (pounds-force per square inch).

AT t Dt s Ds sT sU sUT e De eU eT %El Y.P. E

NOTE A2.8—The expression of tensile properties in terms of the minimum original cross section is almost universally used in practice. In the case of materials exhibiting high extensibility or necking, or both (A2.15), nominal stress calculations may not be meaningful beyond the yield point (A2.21) due to the extensive reduction in cross-sectional area that ensues. Under some circumstances it may be desirable to express the tensile properties per unit of minimum prevailing cross section. These properties are called true tensile properties (that is, true tensile stress, etc.).

A2.19 tensile stress-strain curve—a diagram in which values of tensile stress are plotted as ordinates against corresponding values of tensile strain as abscissas.

Term Load Increment of load Distance between gage marks at any time Original distance between gage marks Distance between gage marks at moment of rupture Increment of distance between gage marks = elongation Minimum cross-sectional area at any time Original cross-sectional area Increment of cross-sectional area Cross-sectional area at point of rupture measured after breaking specimen Cross-sectional area at point of rupture, measured at the moment of rupture Time Increment of time Tensile stress Increment of stress True tensile stress Tensile strength at break (nominal) Tensile strength at break (true) Strain Increment of strain Total strain, at break True strain Percentage elongation Yield point Modulus of elasticity

A2.24 Relations between these various terms may be defined as follows:

A2.20 true strain (see Fig. A2.2) is defined by the following equation for eT: 12

D 638 sU sUT e eU eT %El

= = = = = =

W/Ao (where W is breaking load) W/AT (where W is breaking load) DL/Lo = (L − Lo)/Lo (Lu − Lo)/Lo *LLo dL/L 5 ln L/Lo [(L − Lo)/Lo] 3 100 = e 3 100

Percent reduction of area (nominal) = [(Ao − Au)/Ao] 3 100 Percent reduction of area (true) = [(Ao − AT)/Ao] 3 100 Rate of loading = DW/Dt Rate of stressing (nominal) = Ds/D = (DW]/Ao)/Dt Rate of straining = De/Dt = (DL/Lo)Dt

For the case where the volume of the test specimen does not change during the test, the following three relations hold: sT 5 s~1 1 e! 5 sL/Lo

(A2.2)

sUT 5 sU ~1 1 eU! 5 sU Lu /Lo A 5 Ao /~1 1 e!

FIG. A2.3 Tensile Designations

s sT

= =

W/Ao W/A

SUMMARY OF CHANGES This section identifies the location of selected changes to this test method. For the convenience of the user, Committee D20 has highlighted those changes that may impact the use of this test method. This section may also include descriptions of the changes or reasons for the changes, or both. D 638–02: (1) Revised 9.1 and 9.2. D 638–01: (1) Modified 7.3 regarding conditions for specimen discard. D 638–00: (1) Added 11.1 and renumbered subsequent sections. D 638–99: (1) Added and clarified extensometer classification requirements.

D 638–98: (1) Revised 10.3 and added 12.1.8 to clarify extensometer usage. (2) Added 12.1.14. (3) Replaced reference to Test Methods D 374 with Test Method D 5947 in 2.1 and 5.3.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.

13

D 638 This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or [email protected] (e-mail); or through the ASTM website (www.astm.org).

14



Standard Test Methods for

Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials1 This standard is issued under the fixed designation D 790; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense.

1. Scope * 1.1 These test methods cover the determination of flexural properties of unreinforced and reinforced plastics, including high-modulus composites and electrical insulating materials in the form of rectangular bars molded directly or cut from sheets, plates, or molded shapes. These test methods are generally applicable to both rigid and semirigid materials. However, flexural strength cannot be determined for those materials that do not break or that do not fail in the outer surface of the test specimen within the 5.0 % strain limit of these test methods. These test methods utilize a three-point loading system applied to a simply supported beam. A four-point loading system method can be found in Test Method D 6272. 1.1.1 Procedure A, designed principally for materials that break at comparatively small deflections. 1.1.2 Procedure B, designed particularly for those materials that undergo large deflections during testing. 1.1.3 Procedure A shall be used for measurement of flexural properties, particularly flexural modulus, unless the material specification states otherwise. Procedure B may be used for measurement of flexural strength only. Tangent modulus data obtained by Procedure A tends to exhibit lower standard deviations than comparable data obtained by means of Procedure B. 1.2 Comparative tests may be run in accordance with either procedure, provided that the procedure is found satisfactory for the material being tested. 1.3 The values stated in SI units are to be regarded as the standard. The values provided in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents 2.1 ASTM Standards: D 618 Practice for Conditioning Plastics for Testing2 D 638 Test Method for Tensile Properties of Plastics2 D 883 Terminology Relating to Plastics2 D 4000 Classification System for Specifying Plastic Materials3 D 5947 Test Methods for Physical Dimensions of Solid Plastic Specimens4 D 6272 Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials by Four-Point Bending4 E 4 Practices for Force Verification of Testing Machines5 E 691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method6 3. Terminology 3.1 Definitions—Definitions of terms applying to these test methods appear in Terminology D 883 and Annex A1 of Test Method D 638. 4. Summary of Test Method 4.1 A bar of rectangular cross section rests on two supports and is loaded by means of a loading nose midway between the supports (see Fig. 1). A support span-to-depth ratio of 16:1 shall be used unless there is reason to suspect that a larger span-to-depth ratio may be required, as may be the case for certain laminated materials (see Section 7 and Note 8 for guidance). 4.2 The specimen is deflected until rupture occurs in the outer surface of the test specimen or until a maximum strain (see 12.7) of 5.0 % is reached, whichever occurs first. 4.3 Procedure A employs a strain rate of 0.01 mm/mm/min (0.01 in./in./min) and is the preferred procedure for this test method, while Procedure B employs a strain rate of 0.10 mm/mm/min (0.10 in./in./min).

NOTE 1—These test methods are not technically equivalent to ISO 178.

2

1 These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and are the direct responsibility of Subcommittee D20.10 on Mechanical Properties. Current edition approved April 10, 2002. Published June 2002. Originally published as D 790 – 70. Last previous edition D 790 – 00.

Annual Annual 4 Annual 5 Annual 6 Annual 3

Book Book Book Book Book

of of of of of

ASTM ASTM ASTM ASTM ASTM

Standards, Standards, Standards, Standards, Standards,


1

Vol Vol Vol Vol Vol

08.01. 08.02. 08.03. 03.01. 14.02.

D 790 TABLE 1 Flexural Strength Material ABS DAP thermoset Cast acrylic GR polyester GR polycarbonate SMC

Mean, 103 psi 9.99 14.3 16.3 19.5 21.0 26.0

Values Expressed in Units of % of 103 psi

VrA

VRB

rC

RD

1.59 6.58 1.67 1.43 5.16 4.76

6.05 6.58 11.3 2.14 6.05 7.19

4.44 18.6 4.73 4.05 14.6 13.5

17.2 18.6 32.0 6.08 17.1 20.4

A Vr = within-laboratory coefficient of variation for the indicated material. It is obtained by first pooling the within-laboratory standard deviations of the test results from all of the participating laboratories: Sr = [[(s1)2 + (s2)2 . . . + ( sn)2]/n] 1/2 then Vr = (Sr divided by the overall average for the material) 3 100. B Vr = between-laboratory reproducibility, expressed as the coefficient of variation: SR = {Sr2 + SL2}1/2 where SL is the standard deviation of laboratory means. Then: VR = (S R divided by the overall average for the material) 3 100. C r = within-laboratory critical interval between two test results = 2.8 3 Vr. D R = between-laboratory critical interval between two test results = 2.8 3 VR.

testing, or appropriate corrections shall be made. The load indicating mechanism shall be essentially free from inertial lag at the crosshead rate used. The accuracy of the testing machine shall be verified in accordance with Practices E 4. 6.2 Loading Noses and Supports—The loading nose and supports shall have cylindrical surfaces. In order to avoid excessive indentation, or failure due to stress concentration directly under the loading nose, the radii of the loading nose and supports shall be 5.0 6 0.1 mm (0.197 6 0.004 in.) unless otherwise specified or agreed upon between the interested clients. When other loading noses and supports are used they must comply with the following requirements: they shall have a minimum radius of 3.2 mm (1⁄8 in.) for all specimens, and for specimens 3.2 mm or greater in depth, the radius of the supports may be up to 1.6 times the specimen depth. They shall be this large if significant indentation or compressive failure occurs. The arc of the loading nose in contact with the specimen shall be sufficiently large to prevent contact of the specimen with the sides of the nose (see Fig. 1). The maximum radius of the loading nose shall be no more than 4 times the specimen depth.

NOTE—(a) Minimum radius = 3.2 mm (1⁄8 in.). (b) Maximum radius supports 1.6 times specimen depth; maximum radius loading nose = 4 times specimen depth. FIG. 1

Allowable Range of Loading Nose and Support Radii

5. Significance and Use 5.1 Flexural properties as determined by these test methods are especially useful for quality control and specification purposes. 5.2 Materials that do not fail by the maximum strain allowed under these test methods (3-point bend) may be more suited to a 4-point bend test. The basic difference between the two test methods is in the location of the maximum bending moment and maximum axial fiber stresses. The maximum axial fiber stresses occur on a line under the loading nose in 3-point bending and over the area between the loading noses in 4-point bending. 5.3 Flexural properties may vary with specimen depth, temperature, atmospheric conditions, and the difference in rate of straining as specified in Procedures A and B (see also Note 8). 5.4 Before proceeding with these test methods, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or combination thereof, covered in the materials specification shall take precedence over those mentioned in these test methods. If there are no material specifications, then the default conditions apply. Table 1 in Classification System D 4000 lists the ASTM materials standards that currently exist for plastics.

NOTE 2—Test data have shown that the loading nose and support dimensions can influence the flexural modulus and flexural strength values. The loading nose dimension has the greater influence. Dimensions of the loading nose and supports must be specified in the material specification.

6.3 Micrometers— Suitable micrometers for measuring the width and thickness of the test specimen to an incremental discrimination of at least 0.025 mm (0.001 in.) should be used. All width and thickness measurements of rigid and semirigid plastics may be measured with a hand micrometer with ratchet. A suitable instrument for measuring the thickness of nonrigid test specimens shall have: a contact measuring pressure of 25 6 2.5 kPa (3.6 6 0.36 psi), a movable circular contact foot 6.35 6 0.025 mm (0.250 6 0.001 in.) in diameter and a lower fixed anvil large enough to extend beyond the contact foot in all directions and being parallel to the contact foot within 0.005 mm (0.002 in.) over the entire foot area. Flatness of foot and anvil shall conform to the portion of the Calibration section of Test Methods D 5947.

6. Apparatus 6.1 Testing Machine— A properly calibrated testing machine that can be operated at constant rates of crosshead motion over the range indicated, and in which the error in the load measuring system shall not exceed 61 % of the maximum load expected to be measured. It shall be equipped with a deflection measuring device. The stiffness of the testing machine shall be such that the total elastic deformation of the system does not exceed 1 % of the total deflection of the test specimen during

7. Test Specimens 7.1 The specimens may be cut from sheets, plates, or 2

D 790 be necessary (32:1 or 40:1 are recommended). When laminated materials exhibit low compressive strength perpendicular to the laminations, they shall be loaded with a large radius loading nose (up to four times the specimen depth to prevent premature damage to the outer fibers. 7.4 Molding Materials (Thermoplastics and Thermosets)— The recommended specimen for molding materials is 127 by 12.7 by 3.2 mm (5 by 1⁄2by 1⁄8 in.) tested flatwise on a support span, resulting in a support span-to-depth ratio of 16 (tolerance 61). Thicker specimens should be avoided if they exhibit significant shrink marks or bubbles when molded. 7.5 High-Strength Reinforced Composites, Including Highly Orthotropic Laminates—The span-to-depth ratio shall be chosen such that failure occurs in the outer fibers of the specimens and is due only to the bending moment (see Note 8). A span-to-depth ratio larger than 16:1 may be necessary (32:1 or 40:1 are recommended). For some highly anisotropic composites, shear deformation can significantly influence modulus measurements, even at span-to-depth ratios as high as 40:1. Hence, for these materials, an increase in the span-to-depth ratio to 60:1 is recommended to eliminate shear effects when modulus data are required, it should also be noted that the flexural modulus of highly anisotropic laminates is a strong function of ply-stacking sequence and will not necessarily correlate with tensile modulus, which is not stacking-sequence dependent.

molded shapes, or may be molded to the desired finished dimensions. The actual dimensions used in Section 4.2, Calculation, shall be measured in accordance with Test Methods D 5947. NOTE 3—Any necessary polishing of specimens shall be done only in the lengthwise direction of the specimen.

7.2 Sheet Materials (Except Laminated Thermosetting Materials and Certain Materials Used for Electrical Insulation, Including Vulcanized Fiber and Glass Bonded Mica): 7.2.1 Materials 1.6 mm (1⁄16 in.) or Greater in Thickness— For flatwise tests, the depth of the specimen shall be the thickness of the material. For edgewise tests, the width of the specimen shall be the thickness of the sheet, and the depth shall not exceed the width (see Notes 4 and 5). For all tests, the support span shall be 16 (tolerance 61) times the depth of the beam. Specimen width shall not exceed one fourth of the support span for specimens greater than 3.2 mm (1⁄8 in.) in depth. Specimens 3.2 mm or less in depth shall be 12.7 mm (1⁄2 in.) in width. The specimen shall be long enough to allow for overhanging on each end of at least 10 % of the support span, but in no case less than 6.4 mm (1⁄4 in.) on each end. Overhang shall be sufficient to prevent the specimen from slipping through the supports. NOTE 4—Whenever possible, the original surface of the sheet shall be unaltered. However, where testing machine limitations make it impossible to follow the above criterion on the unaltered sheet, one or both surfaces shall be machined to provide the desired dimensions, and the location of the specimens with reference to the total depth shall be noted. The value obtained on specimens with machined surfaces may differ from those obtained on specimens with original surfaces. Consequently, any specifications for flexural properties on thicker sheets must state whether the original surfaces are to be retained or not. When only one surface was machined, it must be stated whether the machined surface was on the tension or compression side of the beam. NOTE 5—Edgewise tests are not applicable for sheets that are so thin that specimens meeting these requirements cannot be cut. If specimen depth exceeds the width, buckling may occur.

NOTE 8—As a general rule, support span-to-depth ratios of 16:1 are satisfactory when the ratio of the tensile strength to shear strength is less than 8 to 1, but the support span-to-depth ratio must be increased for composite laminates having relatively low shear strength in the plane of the laminate and relatively high tensile strength parallel to the support span.

8. Number of Test Specimens 8.1 Test at least five specimens for each sample in the case of isotropic materials or molded specimens. 8.2 For each sample of anisotropic material in sheet form, test at least five specimens for each of the following conditions. Recommended conditions are flatwise and edgewise tests on specimens cut in lengthwise and crosswise directions of the sheet. For the purposes of this test, “lengthwise” designates the principal axis of anisotropy and shall be interpreted to mean the direction of the sheet known to be stronger in flexure. “Crosswise” indicates the sheet direction known to be the weaker in flexure and shall be at 90° to the lengthwise direction.

7.2.2 Materials Less than 1.6 mm (1⁄16 in.) in Thickness— The specimen shall be 50.8 mm (2 in.) long by 12.7 mm (1⁄2 in.) wide, tested flatwise on a 25.4-mm (1-in.) support span. NOTE 6—Use of the formulas for simple beams cited in these test methods for calculating results presumes that beam width is small in comparison with the support span. Therefore, the formulas do not apply rigorously to these dimensions. NOTE 7—Where machine sensitivity is such that specimens of these dimensions cannot be measured, wider specimens or shorter support spans, or both, may be used, provided the support span-to-depth ratio is at least 14 to 1. All dimensions must be stated in the report (see also Note 6).

9. Conditioning 9.1 Conditioning—Condition the test specimens at 23 6 2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity for not less than 40 h prior to test in accordance with Procedure A of Practice D 618 unless otherwise specified by contract or the relevant ASTM material specification. Reference pre-test conditioning, to settle disagreements, shall apply tolerances of 61°C (1.8°F) and 62 % relative humidity. 9.2 Test Conditions—Conduct the tests at 23 6 2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity unless otherwise specified by contract or the relevant ASTM material specification. Reference testing conditions, to settle disagreements,

7.3 Laminated Thermosetting Materials and Sheet and Plate Materials Used for Electrical Insulation, Including Vulcanized Fiber and Glass-Bonded Mica—For paper-base and fabric-base grades over 25.4 mm (1 in.) in nominal thickness, the specimens shall be machined on both surfaces to a depth of 25.4 mm. For glass-base and nylon-base grades, specimens over 12.7 mm (1⁄2 in.) in nominal depth shall be machined on both surfaces to a depth of 12.7 mm. The support span-to-depth ratio shall be chosen such that failures occur in the outer fibers of the specimens, due only to the bending moment (see Note 8). Therefore, a ratio larger than 16:1 may 3

D 790 shall apply tolerances of 61°C (1.8°F) and 62 % relative humidity.

outer surface of the test specimen has reached 0.05 mm/mm (in./in.) or at break if break occurs prior to reaching the maximum strain (Notes 9 and 10). The deflection at which this strain will occur may be calculated by letting r equal 0.05 mm/mm (in./in.) in Eq 2:

10. Procedure 10.1 Procedure A: 10.1.1 Use an untested specimen for each measurement. Measure the width and depth of the specimen to the nearest 0.03 mm (0.001 in.) at the center of the support span. For specimens less than 2.54 mm (0.100 in.) in depth, measure the depth to the nearest 0.003 mm (0.0005 in.). These measurements shall be made in accordance with Test Methods D 5947. 10.1.2 Determine the support span to be used as described in Section 7 and set the support span to within 1 % of the determined value. 10.1.3 For flexural fixtures that have continuously adjustable spans, measure the span accurately to the nearest 0.1 mm (0.004 in.) for spans less than 63 mm (2.5 in.) and to the nearest 0.3 mm (0.012 in.) for spans greater than or equal to 63 mm (2.5 in.). Use the actual measured span for all calculations. For flexural fixtures that have fixed machined span positions, verify the span distance the same as for adjustable spans at each machined position. This distance becomes the span for that position and is used for calculations applicable to all subsequent tests conducted at that position. See Annex A2 for information on the determination of and setting of the span. 10.1.4 Calculate the rate of crosshead motion as follows and set the machine for the rate of crosshead motion as calculated by Eq 1: R 5 ZL 2/6d

D 5 rL2/6d

(2)

where: D = midspan deflection, mm (in.), r = strain, mm/mm (in./in.), L = support span, mm (in.), and d = depth of beam, mm (in.). NOTE 9—For some materials that do not yield or break within the 5 % strain limit when tested by Procedure A, the increased strain rate allowed by Procedure B (see 10.2) may induce the specimen to yield or break, or both, within the required 5 % strain limit. NOTE 10—Beyond 5 % strain, this test method is not applicable. Some other mechanical property might be more relevant to characterize materials that neither yield nor break by either Procedure A or Procedure B within the 5 % strain limit (for example, Test Method D 638 may be considered).

10.2 Procedure B: 10.2.1 Use an untested specimen for each measurement. 10.2.2 Test conditions shall be identical to those described in 10.1, except that the rate of straining of the outer surface of the test specimen shall be 0.10 mm/mm (in./in.)/min. 10.2.3 If no break has occurred in the specimen by the time the maximum strain in the outer surface of the test specimen has reached 0.05 mm/mm (in./in.), discontinue the test (see Note 10).

(1)

where: R = rate of crosshead motion, mm (in.)/min, L = support span, mm (in.), d = depth of beam, mm (in.), and Z = rate of straining of the outer fiber, mm/mm/min (in./ in./min). Z shall be equal to 0.01. In no case shall the actual crosshead rate differ from that calculated using Eq 1, by more than 610 %. 10.1.5 Align the loading nose and supports so that the axes of the cylindrical surfaces are parallel and the loading nose is midway between the supports. The parallelism of the apparatus may be checked by means of a plate with parallel grooves into which the loading nose and supports will fit when properly aligned (see A2.3). Center the specimen on the supports, with the long axis of the specimen perpendicular to the loading nose and supports. 10.1.6 Apply the load to the specimen at the specified crosshead rate, and take simultaneous load-deflection data. Measure deflection either by a gage under the specimen in contact with it at the center of the support span, the gage being mounted stationary relative to the specimen supports, or by measurement of the motion of the loading nose relative to the supports. Load-deflection curves may be plotted to determine the flexural strength, chord or secant modulus or the tangent modulus of elasticity, and the total work as measured by the area under the load-deflection curve. Perform the necessary toe compensation (see Annex A1) to correct for seating and indentation of the specimen and deflections in the machine. 10.1.7 Terminate the test when the maximum strain in the

11. Retests 11.1 Values for properties at rupture shall not be calculated for any specimen that breaks at some obvious, fortuitous flaw, unless such flaws constitute a variable being studied. Retests shall be made for any specimen on which values are not calculated. 12. Calculation 12.1 Toe compensation shall be made in accordance with Annex A1 unless it can be shown that the toe region of the curve is not due to the take-up of slack, seating of the specimen, or other artifact, but rather is an authentic material response. 12.2 Flexural Stress (sf)—When a homogeneous elastic material is tested in flexure as a simple beam supported at two points and loaded at the midpoint, the maximum stress in the outer surface of the test specimen occurs at the midpoint. This stress may be calculated for any point on the load-deflection curve by means of the following equation (see Notes 11-13): sf 5 3PL/2bd2

(3)

where: s = stress in the outer fibers at midpoint, MPa (psi), P = load at a given point on the load-deflection curve, N (lbf), L = support span, mm (in.), b = width of beam tested, mm (in.), and 4

D 790 d = depth of beam tested, mm (in.). NOTE 11—Eq 3 applies strictly to materials for which stress is linearly proportional to strain up to the point of rupture and for which the strains are small. Since this is not always the case, a slight error will be introduced if Eq 3 is used to calculate stress for materials that are not true Hookean materials. The equation is valid for obtaining comparison data and for specification purposes, but only up to a maximum fiber strain of 5 % in the outer surface of the test specimen for specimens tested by the procedures described herein. NOTE 12—When testing highly orthotropic laminates, the maximum stress may not always occur in the outer surface of the test specimen.7 Laminated beam theory must be applied to determine the maximum tensile stress at failure. If Eq 3 is used to calculate stress, it will yield an apparent strength based on homogeneous beam theory. This apparent strength is highly dependent on the ply-stacking sequence of highly orthotropic laminates. NOTE 13—The preceding calculation is not valid if the specimen slips excessively between the supports.

12.3 Flexural Stress for Beams Tested at Large Support Spans (s f)—If support span-to-depth ratios greater than 16 to 1 are used such that deflections in excess of 10 % of the support span occur, the stress in the outer surface of the specimen for a simple beam can be reasonably approximated with the following equation (see Note 14): sf 5 ~3PL/2bd2!@1 1 6~D/L! 2 2 4~d/L!~D/L!#

NOTE—Curve a: Specimen that breaks before yielding. Curve b: Specimen that yields and then breaks before the 5 % strain limit. Curve c: Specimen that neither yields nor breaks before the 5 % strain limit.

(4)

where: sf, P, L, b, and d are the same as for Eq 3, and D = deflection of the centerline of the specimen at the middle of the support span, mm (in.).

FIG. 2

NOTE 14—When large support span-to-depth ratios are used, significant end forces are developed at the support noses which will affect the moment in a simple supported beam. Eq 4 includes additional terms that are an approximate correction factor for the influence of these end forces in large support span-to-depth ratio beams where relatively large deflections exist.

Typical Curves of Flexural Stress (ßf) Versus Flexural Strain (ef)

according to Eq 3 or Eq 4. Some materials may give a load deflection curve that shows a break point, B, without a yield point (Fig. 2, Curve a) in which case s fB = sfM. Other materials may give a yield deflection curve with both a yield and a break point, B (Fig. 2, Curve b). The flexural stress at break may be calculated for these materials by letting P (in Eq 3 or Eq 4) equal this point, B. 12.7 Stress at a Given Strain—The stress in the outer surface of a test specimen at a given strain may be calculated in accordance with Eq 3 or Eq 4 by letting P equal the load read from the load-deflection curve at the deflection corresponding to the desired strain (for highly orthotropic laminates, see Note 12). 12.8 Flexural Strain, ef—Nominal fractional change in the length of an element of the outer surface of the test specimen at midspan, where the maximum strain occurs. It may be calculated for any deflection using Eq 5:

12.4 Flexural Strength (sfM)—Maximum flexural stress sustained by the test specimen (see Note 12) during a bending test. It is calculated according to Eq 3 or Eq 4. Some materials that do not break at strains of up to 5 % may give a load deflection curve that shows a point at which the load does not increase with an increase in strain, that is, a yield point (Fig. 2, Curve B), Y. The flexural strength may be calculated for these materials by letting P (in Eq 3 or Eq 4) equal this point, Y. 12.5 Flexural Offset Yield Strength—Offset yield strength is the stress at which the stress-strain curve deviates by a given strain (offset) from the tangent to the initial straight line portion of the stress-strain curve. The value of the offset must be given whenever this property is calculated.

ef 5 6Dd/L2

NOTE 15—This value may differ from flexural strength defined in 12.4. Both methods of calculation are described in the annex to Test Method D 638.

(5)

where: ef = strain in the outer surface, mm/mm (in./in.), D = maximum deflection of the center of the beam, mm (in.), L = support span, mm (in.), and d = depth, mm (in.). D = maximum deflection of the center of the beam, mm (in.), L = support span, mm (in.), and

12.6 Flexural Stress at Break (sfB )—Flexural stress at break of the test specimen during a bending test. It is calculated

7 For a discussion of these effects, see Zweben, C., Smith, W. S., and Wardle, M. W., “Test Methods for Fiber Tensile Strength, Composite Flexural Modulus and Properties of Fabric-Reinforced Laminates, “ Composite Materials: Testing and Design (Fifth Conference), ASTM STP 674, 1979, pp. 228–262.

5

D 790 curve. The selected points are to be chosen at two prespecified stress or strain points in accordance with the appropriate material specification or by customer contract. The chosen stress or strain points used for the determination of the chord modulus shall be reported. Calculate the chord modulus, Ef using the following equation:

d = depth, mm (in.). 12.9 Modulus of Elasticity: 12.9.1 Tangent Modulus of Elasticity—The tangent modulus of elasticity, often called the “modulus of elasticity,” is the ratio, within the elastic limit, of stress to corresponding strain. It is calculated by drawing a tangent to the steepest initial straight-line portion of the load-deflection curve and using Eq 6 (for highly anisotropic composites, see Note 16). EB 5 L3m/4bd 3

where: EB = L = b = d = m =

Ef 5 ~sf2 2 sf1!/~ef2 2 ef1!

where: sf2 and sf1 are the flexural stresses, calculated from Eq 3 or Eq 4 and measured at the predefined points on the load deflection curve, and e f2 and ef1 are the flexural strain values, calculated from Eq 5 and measured at the predetermined points on the load deflection curve. 12.10 Arithmetic Mean— For each series of tests, the arithmetic mean of all values obtained shall be calculated to three significant figures and reported as the “average value” for the particular property in question. 12.11 Standard Deviation—The standard deviation (estimated) shall be calculated as follows and be reported to two significant figures:

(6)

modulus of elasticity in bending, MPa (psi), support span, mm (in.), width of beam tested, mm (in.), depth of beam tested, mm (in.), and slope of the tangent to the initial straight-line portion of the load-deflection curve, N/mm (lbf/in.) of deflection.

NOTE 16—Shear deflections can seriously reduce the apparent modulus of highly anisotropic composites when they are tested at low span-todepth ratios.7 For this reason, a span-to-depth ratio of 60 to 1 is recommended for flexural modulus determinations on these composites. Flexural strength should be determined on a separate set of replicate specimens at a lower span-to-depth ratio that induces tensile failure in the outer fibers of the beam along its lower face. Since the flexural modulus of highly anisotropic laminates is a critical function of ply-stacking sequence, it will not necessarily correlate with tensile modulus, which is not stacking-sequence dependent.

s 5 =~ (X 2 2 nX¯ 2! / ~n 2 1!

13. Report 13.1 Report the following information: 13.1.1 Complete identification of the material tested, including type, source, manufacturer’s code number, form, principal dimensions, and previous history (for laminated materials, ply-stacking sequence shall be reported), 13.1.2 Direction of cutting and loading specimens, when appropriate, 13.1.3 Conditioning procedure, 13.1.4 Depth and width of specimen, 13.1.5 Procedure used (A or B), 13.1.6 Support span length, 13.1.7 Support span-to-depth ratio if different than 16:1, 13.1.8 Radius of supports and loading noses if different than 5 mm, 13.1.9 Rate of crosshead motion, 13.1.10 Flexural strain at any given stress, average value and standard deviation, 13.1.11 If a specimen is rejected, reason(s) for rejection, 13.1.12 Tangent, secant, or chord modulus in bending, average value, standard deviation, and the strain level(s) used if secant or chord modulus, 13.1.13 Flexural strength (if desired), average value, and standard deviation, 13.1.14 Stress at any given strain up to and including 5 % (if desired), with strain used, average value, and standard deviation, 13.1.15 Flexural stress at break (if desired), average value,

TABLE 2 Flexural Modulus Mean, 103 psi

ABS DAP thermoset Cast acrylic GR polyester GR polycarbonate SMC

338 485 810 816 1790 1950

Values Expressed in units of % of 103 psi

VrA

VRB

rC

RD

4.79 2.89 13.7 3.49 5.52 10.9

7.69 7.18 16.1 4.20 5.52 13.8

13.6 8.15 38.8 9.91 15.6 30.8

21.8 20.4 45.4 11.9 15.6 39.1

(8)

where: s = estimated standard deviation, X = value of single observation, n = number of observations, and X¯ = arithmetic mean of the set of observations.

12.9.2 Secant Modulus— The secant modulus is the ratio of stress to corresponding strain at any selected point on the stress-strain curve, that is, the slope of the straight line that joins the origin and a selected point on the actual stress-strain curve. It shall be expressed in megapascals (pounds per square inch). The selected point is chosen at a prespecified stress or strain in accordance with the appropriate material specification or by customer contract. It is calculated in accordance with Eq 6 by letting m equal the slope of the secant to the loaddeflection curve. The chosen stress or strain point used for the determination of the secant shall be reported. 12.9.3 Chord Modulus (Ef)—The chord modulus may be calculated from two discrete points on the load deflection

Material

(7)

A Vr = within-laboratory coefficient of variation for the indicated material. It is obtained by first pooling the within-laboratory standard deviations of the test results from all of the participating laboratories: Sr = [[(s1)2 + ( s2)2 . . . + (sn)2]/n] 1/2 then Vr = (Sr divided by the overall average for the material) 3 100. B Vr = between-laboratory reproducibility, expressed as the coefficient of variation: SR = {Sr2 + SL2}1/2 where SL is the standard deviation of laboratory means. Then: VR = (SR divided by the overall average for the material) 3 100. C r = within-laboratory critical interval between two test results = 2.8 3 Vr. D R = between-laboratory critical interval between two test results = 2.8 3 VR.

6

D 790 and standard deviation, 13.1.16 Type of behavior, whether yielding or rupture, or both, or other observations, occurring within the 5 % strain limit, and 13.1.17 Date of specific version of test used.

specific laboratories. The principles of 14.2-14.2.3 would then be valid for such data.

14.2 Concept of “r” and “R” in Tables 1 and 2—If Sr and SR have been calculated from a large enough body of data, and for test results that were averages from testing five specimens for each test result, then: 14.2.1 Repeatability— Two test results obtained within one laboratory shall be judged not equivalent if they differ by more than the r value for that material. r is the interval representing the critical difference between two test results for the same material, obtained by the same operator using the same equipment on the same day in the same laboratory. 14.2.2 Reproducibility— Two test results obtained by different laboratories shall be judged not equivalent if they differ by more than the R value for that material. R is the interval representing the critical difference between two test results for the same material, obtained by different operators using different equipment in different laboratories. 14.2.3 The judgments in 14.2.1 and 14.2.2 will have an approximately 95 % (0.95) probability of being correct. 14.3 Bias—No statement may be made about the bias of these test methods, as there is no standard reference material or reference test method that is applicable.

14. Precision and Bias 8 14.1 Tables 1 and 2 are based on a round-robin test conducted in 1984, in accordance with Practice E 691, involving six materials tested by six laboratories using Procedure A. For each material, all the specimens were prepared at one source. Each “test result” was the average of five individual determinations. Each laboratory obtained two test results for each material. NOTE 17—Caution: The following explanations of r and R (14.214.2.3) are intended only to present a meaningful way of considering the approximate precision of these test methods. The data given in Tables 2 and 3 should not be applied rigorously to the acceptance or rejection of materials, as those data are specific to the round robin and may not be representative of other lots, conditions, materials, or laboratories. Users of these test methods should apply the principles outlined in Practice E 691 to generate data specific to their laboratory and materials, or between

15. Keywords 15.1 flexural properties; plastics; stiffness; strength

8

Supporting data are available from ASTM Headquarters. Request RR: D20 – 1128.

ANNEXES (Mandatory Information) A1. TOE COMPENSATION

A1.1 In a typical stress-strain curve (see Fig. A1.1) there is

a toe region, AC, that does not represent a property of the material. It is an artifact caused by a takeup of slack and alignment or seating of the specimen. In order to obtain correct values of such parameters as modulus, strain, and offset yield point, this artifact must be compensated for to give the corrected zero point on the strain or extension axis. A1.2 In the case of a material exhibiting a region of Hookean (linear) behavior (see Fig. A1.1), a continuation of the linear (CD) region of the curve is constructed through the zero-stress axis. This intersection (B) is the corrected zerostrain point from which all extensions or strains must be measured, including the yield offset (BE), if applicable. The elastic modulus can be determined by dividing the stress at any point along the Line CD (or its extension) by the strain at the same point (measured from Point B, defined as zero-strain). A1.3 In the case of a material that does not exhibit any linear region (see Fig. A1.2), the same kind of toe correction of the zero-strain point can be made by constructing a tangent to the maximum slope at the inflection Point H8. This is extended to intersect the strain axis at Point B8, the corrected zero-strain point. Using Point B8 as zero strain, the stress at any point (G8) on the curve can be divided by the strain at that point to obtain a secant modulus (slope of Line B8 G8). For those materials with no linear region, any attempt to use the tangent through

NOTE—Some chart recorders plot the mirror image of this graph. FIG. A1.1

Material with Hookean Region

7

D 790 yield point may result in unacceptable error.

NOTE—Some chart recorders plot the mirror image of this graph. FIG. A1.2 Material with No Hookean Region

the inflection point as a basis for determination of an offset

A2. MEASURING AND SETTING SPAN

A2.1 For flexural fixtures that have adjustable spans, it is important that the span between the supports is maintained constant or the actual measured span is used in the calculation of stress, modulus, and strain, and the loading nose or noses are positioned and aligned properly with respect to the supports. Some simple steps as follows can improve the repeatability of your results when using these adjustable span fixtures.

FIG. A2.1 Markings on Fixed Specimen Supports

A2.2 Measurement of Span: A2.2.1 This technique is needed to ensure that the correct span, not an estimated span, is used in the calculation of results. A2.2.2 Scribe a permanent line or mark at the exact center of the support where the specimen makes complete contact. The type of mark depends on whether the supports are fixed or rotatable (see Figs. A2.1 and A2.2). A2.2.3 Using a vernier caliper with pointed tips that is readable to at least 0.1 mm (0.004 in.), measure the distance between the supports, and use this measurement of span in the calculations.

FIG. A2.2 Markings on Rotatable Specimen Supports

A2.3 Setting the Span and Alignment of Loading Nose(s)—To ensure a consistent day-to-day setup of the span and ensure the alignment and proper positioning of the loading nose, simple jigs should be manufactured for each of the standard setups used. An example of a jig found to be useful is shown in Fig. A2.3.

8

D 790

FIG. A2.3 Fixture Used to Set Loading Nose and Support Spacing and Alignment

SUMMARY OF CHANGES This section identifies the location of selected changes to these test methods. For the convenience of the user, Committee D20 has highlighted those changes that may impact the use of these test methods. This section may also include descriptions of the changes or reasons for the changes, or both. D 790 – 02: (1) Revised 9.1 and 9.2. D 790 – 00: (1) Revised 12.1. D 790 – 99: (1) Revised 10.1.3.

D 790 – 98: (1) Section 4.2 was rewritten extensively to bring this standard closer to ISO 178. (2) Fig. 2 was added to clarify flexural behaviors that may be observed and to define what yielding and breaking behaviors look like, as well as the appropriate place to select these points on the stress strain curve.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or [email protected] (e-mail); or through the ASTM website (www.astm.org).

9


Designation: D 256 – 00e1

Standard Test Methods for

Determining the Izod Pendulum Impact Resistance of Plastics1 This standard is issued under the fixed designation D 256; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

e1 NOTE—Note 2 was editorially added in April 2002. Title of Table 1 was editorially corrected in April 2002.

1. Scope * 1.1 These test methods cover the determination of the resistance of plastics to “standardized” (see Note 1) pendulumtype hammers, mounted in “standardized” machines, in breaking standard specimens with one pendulum swing (see Note 2). The standard tests for these test methods require specimens made with a milled notch (see Note 3). In Test Methods A, C, and D, the notch produces a stress concentration that increases the probability of a brittle, rather than a ductile, fracture. In Test Method E, the impact resistance is obtained breakage by flexural shock as indicated by the energy extracted from by reversing the notched specimen 180° in the clamping vise. The results of all test methods are reported in terms of energy absorbed per unit of specimen width or per unit of crosssectional area under the notch. (See Note 4.)

of a plastic’s “notch sensitivity” may be obtained with Test Method D by comparing the energies to break specimens having different radii at the base of the notch. NOTE 4—Caution must be exercised in interpreting the results of these standard test methods. The following testing parameters may affect test results significantly: Method of fabrication, including but not limited to processing technology, molding conditions, mold design, and thermal treatments; Method of notching; Speed of notching tool; Design of notching apparatus; Quality of the notch; Time between notching and test; Test specimen thickness, Test specimen width under notch, and Environmental conditioning.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

NOTE 1—The machines with their pendulum-type hammers have been “standardized” in that they must comply with certain requirements, including a fixed height of hammer fall that results in a substantially fixed velocity of the hammer at the moment of impact. However, hammers of different initial energies (produced by varying their effective weights) are recommended for use with specimens of different impact resistance. Moreover, manufacturers of the equipment are permitted to use different lengths and constructions of pendulums with possible differences in pendulum rigidities resulting. (See Section 5.) Be aware that other differences in machine design may exist. The specimens are “standardized” in that they are required to have one fixed length, one fixed depth, and one particular design of milled notch. The width of the specimens is permitted to vary between limits. NOTE 2—Results generated using pendulums that utilize a load cell to record the impact force and thus impact energy, may not be equivalent to results that are generated using manually or digitally encoded testers that measure the energy remaining in the pendulum after impact. NOTE 3—The notch in the Izod specimen serves to concentrate the stress, minimize plastic deformation, and direct the fracture to the part of the specimen behind the notch. Scatter in energy-to-break is thus reduced. However, because of differences in the elastic and viscoelastic properties of plastics, response to a given notch varies among materials. A measure

NOTE 5—These test methods resemble ISO 180:1993 in regard to title only. The contents are significantly different.

2. Referenced Documents 2.1 ASTM Standards: D 618 Practice for Conditioning Plastics for Testing2 D 883 Terminology Relating to Plastics2 D 3641 Practice for Injection Molding Test Specimens of Thermoplastics Molding Extrusion Materials3 D 4000 Classification System for Specifying Plastic Materials3 D 4066 Specification for Nylon Injection and Extrusion Materials3

1 These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and are the direct responsibility of Subcommittee D20.10 on Mechanical Properties. Current edition approved Nov. 10, 2000. Published January 2001. Originally published as D 256 – 26T. Last previous edition D 256 – 97.

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Annual Book of ASTM Standards, Vol 08.01. Annual Book of ASTM Standards, Vol 08.02.


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D 256 TABLE 1 Precision Data, Test Method A—Reversed Notch Izod

NOTE 1—Values in ft·lbf/in. of width (J/m of width). NOTE 2—See Footnote 10. Material Phenolic Acetal Reinforced nylon Polypropylene ABS Polycarbonate

Average 0.57 (30.4) 1.45 (77.4) 1.98 (105.7) 2.66 (142.0) 10.80 (576.7) 16.40 (875.8)

SrA 0.024 0.075 0.083 0.154 0.136 0.295

(1.3) (4.0) (4.4) (8.2) (7.3) (15.8)

SRB

IrC

IRD

Number of Laboratories

0.076 (4.1) 0.604 (32.3) 0.245 (13.1) 0.573 (30.6) 0.585 (31.2) 1.056 (56.4)

0.06 (3.2) 0.21 (11.2) 0.23 (12.3) 0.43 (23.0) 0.38 (20.3) 0.83 (44.3)

0.21 (11.2) 1.70 (90.8) 0.69 (36.8) 1.62 (86.5) 1.65 (88.1) 2.98 (159.1)

19 9 15 24 25 25

A

Sr = within-laboratory standard deviation of the average. SR = between-laboratories standard deviation of the average. C Ir = 2.83 Sr. D IR = 2.83 SR. B

4.1.3 Test Method D provides a measure of the notch sensitivity of a material. The stress-concentration at the notch increases with decreasing notch radius. 4.1.3.1 For a given system, greater stress concentration results in higher localized rates-of-strain. Since the effect of strain-rate on energy-to-break varies among materials, a measure of this effect may be obtained by testing specimens with different notch radii. In the Izod-type test it has been demonstrated that the function, energy-to-break versus notch radius, is reasonably linear from a radius of 0.03 to 2.5 mm (0.001 to 0.100 in.), provided that all specimens have the same type of break. (See 5.8 and 22.1.) 4.1.3.2 For the purpose of this test, the slope, b (see 22.1), of the line between radii of 0.25 and 1.0 mm (0.010 and 0.040 in.) is used, unless tests with the 1.0-mm radius give “nonbreak” results. In that case, 0.25 and 0.50-mm (0.010 and 0.020-in.) radii may be used. The effect of notch radius on the impact energy to break a specimen under the conditions of this test is measured by the value b. Materials with low values of b, whether high or low energy-to-break with the standard notch, are relatively insensitive to differences in notch radius; while the energy-to-break materials with high values of b is highly dependent on notch radius. The parameter b cannot be used in design calculations but may serve as a guide to the designer and in selection of materials. 4.2 Test Method E is similar to Test Method A, except that the specimen is reversed in the vise of the machine 180° to the usual striking position, such that the striker of the apparatus impacts the specimen on the face opposite the notch. (See Fig. 1, Fig. 2.) Test Method E is used to give an indication of the unnotched impact resistance of plastics; however, results obtained by the reversed notch method may not always agree with those obtained on a completely unnotched specimen. (See 28.1.)7,8

D 4812 Test Methods for Unnoticed Cantilever Beam Impact Strength of Plastics4 E 691 Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods5 2.2 ISO Standard: ISO 180:1993 Plastics—Determination of Izod Impact Strength of Rigid Materials6 3. Terminology 3.1 Definitions— For definitions related to plastics see Terminology D 883. 3.2 Definitions of Terms Specific to This Standard: 3.2.1 cantilever—a projecting beam clamped at only one end. 3.2.2 notch sensitivity—a measure of the variation of impact energy as a function of notch radius. 4. Types of Tests 4.1 Four similar methods are presented in these test methods. (See Note 6.) All test methods use the same testing machine and specimen dimensions. There is no known means for correlating the results from the different test methods. NOTE 6—Test Method B for Charpy has been removed and is being revised under a new standard.

4.1.1 In Test Method A, the specimen is held as a vertical cantilever beam and is broken by a single swing of the pendulum. The line of initial contact is at a fixed distance from the specimen clamp and from the centerline of the notch and on the same face as the notch. 4.1.2 Test Method C is similar to Test Method A, except for the addition of a procedure for determining the energy expended in tossing a portion of the specimen. The value reported is called the “estimated net Izod impact resistance.” Test Method C is preferred over Test Method A for materials that have an Izod impact resistance of less than 27 J/m (0.5 ft·lbf/in.) under notch. (See Appendix X4 for optional units.) The differences between Test Methods A and C become unimportant for materials that have an Izod impact resistance higher than this value.

5. Significance and Use 5.1 Before proceeding with these test methods, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, and

7 Supporting data giving results of the interlaboratory tests are available from ASTM Headquarters. Request RR: D20-1021. 8 Supporting data giving results of the interlaboratory tests are available from ASTM Headquarters. Request RR: D20-1026.

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Annual Book of ASTM Standards, Vol 08.03. Annual Book of ASTM Standards, Vol 14.02. 6 Available from American National Standards Institute, 11 W. 42nd St., 13th Floor, New York, NY 10036. 5

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D 256 5.3.4 Energy to bend the specimen; 5.3.5 Energy to produce vibration in the pendulum arm; 5.3.6 Energy to produce vibration or horizontal movement of the machine frame or base; 5.3.7 Energy to overcome friction in the pendulum bearing and in the excess energy indicating mechanism, and to overcome windage (pendulum air drag); 5.3.8 Energy to indent or deform plastically the specimen at the line of impact; and 5.3.9 Energy to overcome the friction caused by the rubbing of the striker (or other part of the pendulum) over the face of the bent specimen. 5.4 For relatively brittle materials, for which fracture propagation energy is small in comparison with the fracture initiation energy, the indicated impact energy absorbed is, for all practical purposes, the sum of factors 5.3.1 and 5.3.3. The toss correction (see 5.3.3) may represent a very large fraction of the total energy absorbed when testing relatively dense and brittle materials. Test Method C shall be used for materials that have an Izod impact resistance of less than 27 J/m (0.5 ft·lbf/in.). (See Appendix X4 for optional units.) The toss correction obtained in Test Method C is only an approximation of the toss error, since the rotational and rectilinear velocities may not be the same during the re-toss of the specimen as for the original toss, and because stored stresses in the specimen may have been released as kinetic energy during the specimen fracture. 5.5 For tough, ductile, fiber filled, or cloth-laminated materials, the fracture propagation energy (see 5.3.2) may be large compared to the fracture initiation energy (see 5.3.1). When testing these materials, factors (see 5.3.2, 5.3.5, and 5.3.9) can become quite significant, even when the specimen is accurately machined and positioned and the machine is in good condition with adequate capacity. (See Note 7.) Bending (see 5.3.4) and indentation losses (see 5.3.8) may be appreciable when testing soft materials.

FIG. 2 Relationship of Vise, Specimen, and Striking Edge to Each Other for Test Method E

NOTE 7—Although the frame and base of the machine should be sufficiently rigid and massive to handle the energies of tough specimens without motion or excessive vibration, the design must ensure that the center of percussion be at the center of strike. Locating the striker precisely at the center of percussion reduces vibration of the pendulum arm when used with brittle specimens. However, some losses due to pendulum arm vibration, the amount varying with the design of the pendulum, will occur with tough specimens, even when the striker is properly positioned.

FIG. 1 Relationship of Vise, Specimen, and Striking Edge to Each Other for Izod Test Methods A and C

5.6 In a well-designed machine of sufficient rigidity and mass, the losses due to factors 5.3.6 and 5.3.7 should be very small. Vibrational losses (see 5.3.6) can be quite large when wide specimens of tough materials are tested in machines of insufficient mass, not securely fastened to a heavy base. 5.7 With some materials, a critical width of specimen may be found below which specimens will appear ductile, as evidenced by considerable drawing or necking down in the region behind the notch and by a relatively high-energy absorption, and above which they will appear brittle as evidenced by little or no drawing down or necking and by a relatively low-energy absorption. Since these methods permit a variation in the width of the specimens, and since the width dictates, for many materials, whether a brittle, low-energy break or a ductile, high energy break will occur, it is necessary

testing parameters covered in the materials specification shall take precedence over those mentioned in these test methods. If there is no material specification, then the default conditions apply. 5.2 The excess energy pendulum impact test indicates the energy to break standard test specimens of specified size under stipulated parameters of specimen mounting, notching, and pendulum velocity-at-impact. 5.3 The energy lost by the pendulum during the breakage of the specimen is the sum of the following: 5.3.1 Energy to initiate fracture of the specimen; 5.3.2 Energy to propagate the fracture across the specimen; 5.3.3 Energy to throw the free end (or ends) of the broken specimen (“toss correction”); 3

D 256 pendulum holding and releasing mechanism and a pointer and dial mechanism for indicating the excess energy remaining in the pendulum after breaking the specimen. Optionally, an electronic digital display or computer can be used in place of the dial and pointer to measure the energy loss and indicate the breaking energy of the specimen. 6.2 A jig for positioning the specimen in the vise and graphs or tables to aid in the calculation of the correction for friction and windage also should be included. One type of machine is shown in Fig. 3. One design of specimen-positioning jig is illustrated in Fig. 4. Detailed requirements are given in subsequent paragraphs. General test methods for checking and calibrating the machine are given in Appendix X1. Additional instructions for adjusting a particular machine should be supplied by the manufacturer. 6.3 The pendulum shall consist of a single or multimembered arm with a bearing on one end and a head, containing the striker, on the other. The arm must be sufficiently rigid to maintain the proper clearances and geometric relationships between the machine parts and the specimen and to minimize vibrational energy losses that are always included in the measured impact resistance. Both simple and compound pendulum designs may comply with this test method. 6.4 The striker of the pendulum shall be hardened steel and shall be a cylindrical surface having a radius of curvature of 0.80 6 0.20 mm (0.031 6 0.008 in.) with its axis horizontal and perpendicular to the plane of swing of the pendulum. The line of contact of the striker shall be located at the center of percussion of the pendulum within 62.54 mm (60.100 in.) (See Note 9.) Those portions of the pendulum adjacent to the cylindrical striking edge shall be recessed or inclined at a suitable angle so that there will be no chance for other than this cylindrical surface coming in contact with the specimen during the break.

that the width be stated in the specification covering that material and that the width be reported along with the impact resistance. In view of the preceding, one should not make comparisons between data from specimens having widths that differ by more than a few mils. 5.8 The type of failure for each specimen shall be recorded as one of the four categories listed as follows: C H

P

NB

Complete Break—A break where the specimen separates into two or more pieces. Hinge Break—An incomplete break, such that one part of the specimen cannot support itself above the horizontal when the other part is held vertically (less than 90° included angle). Partial Break—An incomplete break that does not meet the definition for a hinge break but has fractured at least 90 % of the distance between the vertex of the notch and the opposite side. Non-Break—An incomplete break where the fracture extends less than 90 % of the distance between the vertex of the notch and the opposite side.

For tough materials, the pendulum may not have the energy necessary to complete the breaking of the extreme fibers and toss the broken piece or pieces. Results obtained from “nonbreak” specimens shall be considered a departure from standard and shall not be reported as a standard result. Impact resistance cannot be directly compared for any two materials that experience different types of failure as defined in the test method by this code. Averages reported must likewise be derived from specimens contained within a single failure category. This letter code shall suffix the reported impact identifying the types of failure associated with the reported value. If more than one type of failure is observed for a sample material, then the report will indicate the average impact resistance for each type of failure, followed by the percent of the specimens failing in that manner and suffixed by the letter code. 5.9 The value of the impact methods lies mainly in the areas of quality control and materials specification. If two groups of specimens of supposedly the same material show significantly different energy absorptions, types of breaks, critical widths, or critical temperatures, it may be assumed that they were made of different materials or were exposed to different processing or conditioning environments. The fact that a material shows twice the energy absorption of another under these conditions of test does not indicate that this same relationship will exist under another set of test conditions. The order of toughness may even be reversed under different testing conditions. NOTE 8—A documented discrepancy exists between manual and digital impact testers, primarily with thermoset materials, including phenolics, having an impact value of less than 54 J/m (1 ft-lb/in.). Comparing data on the same material, tested on both manual and digital impact testers, may show the data from the digital tester to be significantly lower than data from a manual tester. In such cases a correlation study may be necessary to properly define the true relationship between the instruments.

TEST METHOD A—CANTILEVER BEAM TEST 6. Apparatus 6.1 The machine shall consist of a massive base on which is mounted a vise for holding the specimen and to which is connected, through a rigid frame and bearings, a pendulumtype hammer. (See 6.2.) The machine must also have a

FIG. 3 Cantilever Beam (Izod-Type) Impact Machine

4

D 256 ft·lbf). This pendulum shall be used with all specimens that extract less than 85 % of this energy. Heavier pendulums shall be provided for specimens that require more energy to break. These may be separate interchangeable pendulums or one basic pendulum to which extra pairs of equal calibrated weights may be rigidly attached to opposite sides of the pendulum. It is imperative that the extra weights shall not significantly change the position of the center of percussion or the free-hanging rest point of the pendulum (that would consequently take the machine outside of the allowable calibration tolerances). A range of pendulums having energies from 2.7 to 21.7 J (2 to 16 ft·lbf) has been found to be sufficient for use with most plastic specimens and may be used with most machines. A series of pendulums such that each has twice the energy of the next will be found convenient. Each pendulum shall have an energy within 6 0.5 % of its nominal capacity. 6.8 A vise shall be provided for clamping the specimen rigidly in position so that the long axis of the specimen is vertical and at right angles to the top plane of the vise. (See Fig. 1.) This top plane shall bisect the angle of the notch with a tolerance of 0.12 mm (0.005 in.). Correct positioning of the specimen is generally done with a jig furnished with the machine. The top edges of the fixed and moveable jaws shall have a radius of 0.25 6 0.12 mm (0.010 6 0.005 in.). For specimens whose thickness approaches the lower limiting value of 3.00 mm (0.118 in.), means shall be provided to prevent the lower half of the specimen from moving during the clamping or testing operations (see Fig. 4 and Note 11.)

FIG. 4 Jig for Positioning Specimen for Clamping

NOTE 9—The distance from the axis of support to the center of percussion may be determined experimentally from the period of small amplitude oscillations of the pendulum by means of the following equation: L 5 ~g/4p 2!p 2

NOTE 11—Some plastics are sensitive to clamping pressure; therefore, cooperating laboratories should agree upon some means of standardizing the clamping force. One method is using a torque wrench on the screw of the specimen vise. If the faces of the vise or specimen are not flat and parallel, a greater sensitivity to clamping pressure may be evident. See the calibration procedure in Appendix X2 for adjustment and correction instructions for faulty instruments.

where: L = distance from the axis of support to the center of percussion, m (or ft), g = local gravitational acceleration (known to an accuracy of one part in one thousand), m/s2 (or ft/s 2), p = 3.1416 (4p 2 = 39.48), and p = period, s, of a single complete swing (to and fro) determined by averaging at least 20 consecutive and uninterrupted swings. The angle of swing shall be less than 5° each side of center.

6.9 When the pendulum is free hanging, the striking surface shall come within 0.2 % of scale of touching the front face of a standard specimen. During an actual swing this element shall make initial contact with the specimen on a line 22.00 6 0.05 mm (0.87 6 0.002 in.) above the top surface of the vise. 6.10 Means shall be provided for determining energy remaining in the pendulum after breaking the specimen. This may consist of a pointer and dial mechanism which indicate the height of rise of the pendulum beyond the point of impact in terms of energy removed from that specific pendulum. Since the indicated remaining energy must be corrected for pendulum-bearing friction, pointer friction, pointer inertia, and pendulum windage, instructions for making these corrections are included in 10.3 and Annex A1 and Annex A2. Optionally, an electronic digital display or computer can be used in place of the dial and pointer to measure the energy loss and indicate the breaking energy of the specimen. If the electronic display does not automatically correct for windage and friction, it shall be incumbent for the operator to determine the energy loss manually. (See Note 12.)

6.5 The position of the pendulum holding and releasing mechanism shall be such that the vertical height of fall of the striker shall be 610 6 2 mm (24.0 6 0.1 in.). This will produce a velocity of the striker at the moment of impact of approximately 3.5 m (11.4 ft)/s. (See Note 10.) The mechanism shall be so constructed and operated that it will release the pendulum without imparting acceleration or vibration to it. NOTE 10— V 5 ~2gh!0.5 where: V = velocity of the striker at the moment of impact (m/s), g = local gravitational acceleration (m/s2), and h = vertical height of fall of the striker (m). This assumes no windage or friction.

6.6 The effective length of the pendulum shall be between 0.33 and 0.40 m (12.8 and 16.0 in.) so that the required elevation of the striker may be obtained by raising the pendulum to an angle between 60 and 30° above the horizontal. 6.7 The machine shall be provided with a basic pendulum capable of delivering an energy of 2.7 6 0.14 J (2.00 6 0.10

NOTE 12—Many digital indicating systems automatically correct for windage and friction. The equipment manufacturer may be consulted for details concerning how this is performed, or if it is necessary to determine

5

D 256 result in an equivalent accuracy. Appendix X1 also describes a dynamic test for checking certain features of the machine and specimen.

the means for manually calculating the energy loss due to windage and friction.

6.11 The vise, pendulum, and frame shall be sufficiently rigid to maintain correct alignment of the hammer and specimen, both at the moment of impact and during the propagation of the fracture, and to minimize energy losses due to vibration. The base shall be sufficiently massive that the impact will not cause it to move. The machine shall be so designed, constructed, and maintained that energy losses due to pendulum air drag (windage), friction in the pendulum bearings, and friction and inertia in the excess energy-indicating mechanism are held to a minimum. 6.12 A check of the calibration of an impact machine is difficult to make under dynamic conditions. The basic parameters are normally checked under static conditions; if the machine passes the static tests, then it is assumed to be accurate. The calibration procedure in Appendix X2 should be used to establish the accuracy of the equipment. However, for some machine designs it might be necessary to change the recommended method of obtaining the required calibration measurements. Other methods of performing the required checks may be substituted, provided that they can be shown to

A B C D E

7. Test Specimens 7.1 The test specimens shall conform to the dimensions and geometry of Fig. 5, except as modified in accordance with 7.2, 7.3, 7.4, and 7.5. To ensure the correct contour and conditions of the specified notch, all specimens shall be notched as directed in Section 8. 7.2 Molded specimens shall have a width between 3.0 and 12.7 mm (0.118 and 0.500 in.). Use the specimen width as specified in the material specification or as agreed upon between the supplier and the customer. All specimens having one dimension less than 12.7 mm (0.500 in.) shall have the notch cut on the shorter side. Otherwise, all compressionmolded specimens shall be notched on the side parallel to the direction of application of molding pressure. (Due to the draft of the mold, the notched surface and the opposite surface may not be parallel in molded specimens. Therefore, it is essential that the notched surface be machined parallel to its opposite surface within 0.025 mm (0.001 in.), removing a minimum of

10.16 6 0.05 32 6 1 64 6 2 0.25R 6 0.05 12.7 6 0.2

0.400 6 0.002 1.26 6 0.04 2.50 6 0.08 0.010R 6 0.002 0.500 6 0.008

FIG. 5 Dimensions of Izod-Type Test Specimen

6

D 256 specimens shall be noted in the report of test results. 7.4.2 Care must be taken to select a solvent or adhesive that will not affect the impact resistance of the material under test. If solvents or solvent-containing adhesives are employed, a conditioning procedure shall be established to ensure complete removal of the solvent prior to test. 7.5 Each specimen shall be free of twist (see Note 13) and shall have mutually perpendicular pairs of plane parallel surfaces and free from scratches, pits, and sink marks. The specimens shall be checked for compliance with these requirements by visual observation against straightedges, squares, and flat plates, and by measuring with micrometer calipers. Any specimen showing observable or measurable departure from one or more of these requirements shall be rejected or machined to the proper size and shape before testing.

material in the process, so as to remain within the allowable tolerance for the specimen depth). (See Fig. 5.) 7.2.1 Extreme care must be used in handling specimens less than 6.4 mm (0.250 in.) wide. Such specimens must be accurately positioned and supported to prevent twist or lateral buckling during the test. Some materials, furthermore, are very sensitive to clamping pressure (see Note 11). 7.2.2 A critical investigation of the mechanics of impact testing has shown that tests made upon specimens under 6.4 mm (0.250 in.) wide absorb more energy due to crushing, bending, and twisting than do wider specimens. Therefore, specimens 6.4 mm (0.250 in.) or over in width are recommended. The responsibility for determining the minimum specimen width shall be the investigator’s, with due reference to the specification for that material. 7.2.3 Material specification should be consulted for preferred molding conditions. The type of mold and molding machine used and the flow behavior in the mold cavity will influence the impact resistance obtained. A specimen taken from one end of a molded plaque may give different results than a specimen taken from the other end. Cooperating laboratories should therefore agree on standard molds conforming to the material specification. Practice D 3641 can be used as a guide for general molding tolerances, but refer to the material specification for specific molding conditions. 7.2.4 The impact resistance of a plastic material may be different if the notch is perpendicular to, rather than parallel to, the direction of molding. The same is true for specimens cut with or across the grain of an anisotropic sheet or plate. 7.3 For sheet materials, the specimens shall be cut from the sheet in both the lengthwise and crosswise directions unless otherwise specified. The width of the specimen shall be the thickness of the sheet if the sheet thickness is between 3.0 and 12.7 mm (0.118 and 0.500 in.). Sheet material thicker than 12.7 mm shall be machined down to 12.7 mm. Specimens with a 12.7-mm square cross section may be tested either edgewise or flatwise as cut from the sheet. When specimens are tested flatwise, the notch shall be made on the machined surface if the specimen is machined on one face only. When the specimen is cut from a thick sheet, notation shall be made of the portion of the thickness of the sheet from which the specimen was cut, for example, center, top, or bottom surface. 7.4 The practice of cementing, bolting, clamping, or otherwise combining specimens of substandard width to form a composite test specimen is not recommended and should be avoided since test results may be seriously affected by interface effects or effects of solvents and cements on energy absorption of composite test specimens, or both. However, if Izod test data on such thin materials are required when no other means of preparing specimens are available, and if possible sources of error are recognized and acceptable, the following technique of preparing composites may be utilized. 7.4.1 The test specimen shall be a composite of individual thin specimens totaling 6.4 to 12.7 mm (0.250 to 0.500 in.) in width. Individual members of the composite shall be accurately aligned with each other and clamped, bolted, or cemented together. The composite shall be machined to proper dimensions and then notched. In all such cases the use of composite

NOTE 13—A specimen that has a slight twist to its notched face of 0.05 mm (0.002 in.) at the point of contact with the pendulum striking edge will be likely to have a characteristic fracture surface with considerable greater fracture area than for a normal break. In this case the energy to break and toss the broken section may be considerably larger (20 to 30 %) than for a normal break. A tapered specimen may require more energy to bend it in the vise before fracture.

8. Notching Test Specimens 8.1 Notching shall be done on a milling machine, engine lathe, or other suitable machine tool. Both the feed speed and the cutter speed shall be constant throughout the notching operation (see Note 14). Provision for cooling the specimen with either a liquid or gas coolant is recommended. A singletooth cutter shall be used for notching the specimen, unless notches of an equivalent quality can be produced with a multi-tooth cutter. Single-tooth cutters are preferred because of the ease of grinding the cutter to the specimen contour and because of the smoother cut on the specimen. The cutting edge shall be carefully ground and honed to ensure sharpness and freedom from nicks and burrs. Tools with no rake and a work relief angle of 15 to 20° have been found satisfactory. NOTE 14—For some thermoplastics, cutter speeds from 53 to 150 m/min (175 to 490 ft/min) at a feed speed of 89 to 160 mm/min (3.5 to 6.3 in./min) without a water coolant or the same cutter speeds at a feed speed of from 36 to 160 mm/min (1.4 to 6.3 in./min) with water coolant produced suitable notches.

8.2 Specimens may be notched separately or in a group. However, in either case an unnotched backup or “dummy bar” shall be placed behind the last specimen in the sample holder to prevent distortion and chipping by the cutter as it exits from the last test specimen. 8.3 The profile of the cutting tooth or teeth shall be such as to produce a notch of the contour and depth in the test specimen as specified in Fig. 5 (see Note 15). The included angle of the notch shall be 45 6 1° with a radius of curvature at the apex of 0.25 6 0.05 mm (0.010 6 0.002 in.). The plane bisecting the notch angle shall be perpendicular to the face of the test specimen within 2°. NOTE 15—There is evidence that notches in materials of widely varying physical dimensions may differ in contour even when using the same cutter. If the notch in the specimen should take the contour of the cutter, then the contour of the tip of the cutter may be checked instead of the notch in the specimen for single-tooth cutters. Under the same condition,

7

D 256 tions are not selected.9 The notching parameters used shall not alter the physical state of the material such as by raising the temperature of a thermoplastic above its glass transition temperature. In general, high cutter speeds, slow feed rates, and lack of coolant induce more thermal damage than a slow cutter speed, fast feed speed, and the use of a coolant. Too high a feed speed/cutter speed ratio, however, may cause impacting and

multi-tooth cutters may be checked by measuring the contour of a strip of soft metal shim inserted between two specimens for notching.

8.4 The depth of the plastic material remaining in the specimen under the notch shall be 10.16 6 0.05 mm (0.400 6 0.002 in.). This dimension shall be measured, with a micrometer or other suitable measuring device. (See Fig. 6.) 8.5 Cutter speed and feed speed should be chosen appropriate for the material being tested since the quality of the notch may be adversely affected by thermal deformations and stresses induced during the cutting operation if proper condi-

NOTE NOTE NOTE NOTE NOTE NOTE NOTE

9 Supporting data are available from ASTM Headquarters. Request RR: D201066.

1—These views not to scale. 2—Micrometer to be satin-chrome finished with friction thimble. 3—Special anvil for micrometer caliper 0 to 25.4 mm range (50.8 mm frame) (0 to 1 in. range (2-in. frame)). 4—Anvil to be oriented with respect to frame as shown. 5—Anvil and spindle to have hardened surfaces. 6—Range: 0 to 25.4 mm (0 to 1 in. in thousandths of an inch). 7—Adjustment must be at zero when spindle and anvil are in contact. FIG. 6 Early (ca. 1970) Version of a Notch-Depth Micrometer

8

D 256 cracking of the specimen. The range of cutter speed/feed ratios possible to produce acceptable notches can be extended by the use of a suitable coolant. (See Note 16.) In the case of new types of plastics, it is necessary to study the effect of variations in the notching conditions. (See Note 17.)

pendulum that is expected to break each specimen in the group with a loss of not more than 85 % of its energy (see Note 19). Check the machine with the proper pendulum in place for conformity with the requirements of Section 6 before starting the tests. (See Appendix X1.)

NOTE 16—Water or compressed gas is a suitable coolant for many plastics. NOTE 17—Embedded thermocouples, or another temperature measuring device, can be used to determine the temperature rise in the material near the apex of the notch during machining. Thermal stresses induced during the notching operation can be observed in transparent materials by viewing the specimen at low magnification between crossed polars in monochromatic light.

NOTE 19—Ideally an impact test would be conducted at a constant test velocity. In a pendulum-type test, the velocity decreases as the fracture progresses. For specimens that have an impact energy approaching the capacity of the pendulum there is insufficient energy to complete the break and toss. By avoiding the higher 15 % scale energy readings, the velocity of the pendulum will not be reduced below 1.3 m/s (4.4 ft/s). On the other hand, the use of too heavy a pendulum would reduce the sensitivity of the reading.

8.6 The specimen notch produced by each cutter will be examined, at a minimum, after every 500 notches. The notch in the specimen, made of the material to be tested, shall be inspected and verified. One procedure for the inspection and verification of the notch is presented in Appendix X1. Each type of material being notched must be inspected and verified at that time. If the angle or radius does not fall within the specified limits for materials of satisfactory machining characteristics, then the cutter shall be replaced with a newly sharpened and honed one. (See Note 18.)

10.3 If the machine is equipped with a mechanical pointer and dial, perform the following operations before testing the specimens: 10.3.1 With the excess energy indicating pointer in its normal starting position but without a specimen in the vise, release the pendulum from its normal starting position and note the position the pointer attains after the swing as one reading of Factor A. 10.3.2 Without resetting the pointer, raise the pendulum and release again. The pointer should move up the scale an additional amount. Repeat (10.3.2) until a swing causes no additional movement of the pointer and note the final reading as one reading of Factor B (see Note 20). 10.3.3 Repeat the preceding two operations several times and calculate and record the average A and B readings.

NOTE 18—A carbide-tipped or industrial diamond-tipped notching cutter is recommended for longer service life.

9. Conditioning 9.1 Conditioning—Condition the test specimens at 23 6 2°C (73 6 3.6°F) and 50 6 5 % relative humidity for not less than 40 h after notching and prior to testing in accordance with Procedure A of Practice D 618, unless it can be documented (between supplier and customer) that a shorter conditioning time is sufficient for a given material to reach equilibrium of impact resistance. 9.1.1 Note that for some hygroscopic materials, such as nylons, the material specifications (for example, Specification D 4066) call for testing “dry as-molded specimens.” Such requirements take precedence over the above routine preconditioning to 50 % relative humidity and require sealing the specimens in water vapor-impermeable containers as soon as molded and not removing them until ready for testing. 9.2 Test Conditions—Conduct tests in the standard laboratory atmosphere of 23 6 2°C (73 6 3.6°F) and 50 6 5 % relative humidity, unless otherwise specified in the material specification or by customer requirements. In cases of disagreement, the tolerances shall be 61°C (61.8°F) and 6 2 % relative humidity.

NOTE 20—Factor B is an indication of the energy lost by the pendulum to friction in the pendulum bearings and to windage. The difference A – B is an indication of the energy lost to friction and inertia in the excess energy indicating mechanism. However, the actual corrections will be smaller than these factors, since in an actual test the energy absorbed by the specimen prevents the pendulum from making a full swing. Therefore, the indicated breaking energy of the specimen must be included in the calculation of the machine correction before determining the breaking energy of the specimen (see 10.7). The A and B values also provide an indication of the condition of the machine.

10.3.4 If excessive friction is indicated, the machine shall be adjusted before starting a test. If the machine is equipped with a digital energy indicating system, follow the manufacturer’s instructions to correct for windage and friction. If excessive friction is indicated, the machine shall be adjusted before starting a test. 10.4 Check the specimens for conformity with the requirements of Sections 7, 8, and 10.1. 10.5 Measure the width and depth to the nearest 0.025 mm (0.001 in.) after notching of each specimen. Measure the width in the region of the notch. A micrometer or other measuring device is necessary for measuring the depth. (See Fig. 6.) 10.6 Position the specimen precisely (see 6.7) so that it is rigidly, but not too tightly (see Note 11), clamped in the vise. Pay special attention to ensure that the “impacted end” of the specimen as shown and dimensioned in Fig. 5 is the end projecting above the vise. Release the pendulum and record the excess energy remaining in the pendulum after breaking the specimen, together with a description of the appearance of the broken specimen (see failure categories in 5.8). 10.7 Subtract the windage and friction correction from the

10. Procedure 10.1 At least five and preferably ten or more individual determinations of impact resistance must be made on each sample to be tested under the conditions prescribed in Section 9. Each group shall consist of specimens with the same nominal width (60.13 mm (60.005 in.)). In the case of specimens cut from sheets that are suspected of being anisotropic, prepare and test specimens from each principal direction (lengthwise and crosswise to the direction of anisotropy). 10.2 Estimate the breaking energy for the specimen and select a pendulum of suitable energy. Use the lightest standard 9

D 256 (kJ/m 2 (ft·lbf/in.2)) may also need to be reported (see Appendix X4), and 11.1.11 The percent of specimens failing in each category suffixed by the corresponding letter code from 5.8.

indicated breaking energy of the specimen, unless determined automatically by the indicating system (that is, digital display or computer). If a mechanical dial and pointer is employed, use the A and B factors and the appropriate tables or the graph described in Annex A1 and Annex A2 to determine the correction. For those digital systems that do not automatically compensate for windage and friction, follow the manufacturer’s procedure for performing this correction. 10.7.1 In other words, either manually or automatically, the windage and friction correction value is subtracted from the uncorrected, indicated breaking energy to obtain the new breaking energy. Compare the net value so found with the energy requirement of the hammer specified in 10.2. If a hammer of improper energy was used, discard the result and make additional tests on new specimens with the proper hammer. (See Annex A1 and Annex A2.) 10.8 Divide the net value found in 10.7 by the measured width of the particular specimen to obtain the impact resistance under the notch in J/m (ft·lbf/in.). If the optional units of kJ/m 2 2 (ft·lbf/in. ) are used, divide the net value found in 10.7 by the measured width and depth under the notch of the particular specimen to obtain the impact strength. The term, “depth under the notch,” is graphically represented by Dimension A in Fig. 5. Consequently, the cross-sectional area (width times depth under the notch) will need to be reported. (See Appendix X4.) 10.9 Calculate the average Izod impact resistance of the group of specimens. However, only values of specimens having the same nominal width and type of break may be averaged. Values obtained from specimens that did not break in the manner specified in 5.8 shall not be included in the average. Also calculate the standard deviation of the group of values.

TEST METHOD C—CANTILEVER BEAM TEST FOR MATERIALS OF LESS THAN 27 J/m (0.5 ft·lbf/in.) 12. Apparatus 12.1 The apparatus shall be the same as specified in Section 6. 13. Test Specimens 13.1 The test specimens shall be the same as specified in Section 7. 14. Notching Test Specimens 14.1 Notching test specimens shall be the same as specified in Section 8. 15. Conditioning 15.1 Specimen conditioning and test environment shall be in accordance with Section 9. 16. Procedure 16.1 The procedure shall be the same as in Section 10 with the addition of a procedure for estimating the energy to toss the broken specimen part. 16.1.1 Make an estimate of the magnitude of the energy to toss each different type of material and each different specimen size (width). This is done by repositioning the free end of the broken specimen on the clamped portion and striking it a second time with the pendulum released in such a way as to impart to the specimen approximately the same velocity it had attained during the test. This is done by releasing the pendulum from a height corresponding to that to which it rose following the breakage of the test specimen. The energy to toss is then considered to be the difference between the reading previously described and the free swing reading obtained from this height. A reproducible method of starting the pendulum from the proper height must be devised.

11. Report 11.1 Report the following information: 11.1.1 The test method used (Test Method A, C, D, or E), 11.1.2 Complete identification of the material tested, including type source, manufacturer’s code number, and previous history, 11.1.3 A statement of how the specimens were prepared, the testing conditions used, the number of hours the specimens were conditioned after notching, and, for sheet materials, the direction of testing with respect to anisotropy, if any, 11.1.4 The capacity of the pendulum in joules, or foot pound-force, or inch pound-force, 11.1.5 The width and depth under the notch of each specimen tested, 11.1.6 The total number of specimens tested per sample of material, 11.1.7 The type of failure (see 5.8), 11.1.8 The impact resistance must be reported in J/m (ft·lbf/in.); the optional units of kJ/m2 (ft·lbf/in.2) may also be required (see 10.8), 11.1.9 The number of those specimens that resulted in failures which conforms to each of the requirement categories in 5.8, 11.1.10 The average impact resistance and standard deviation (in J/m (ft·lbf/in.)) for those specimens in each failure category, except non-break as presented in 5.8. Optional units

17. Report 17.1 Report the following information: 17.1.1 Same as 11.1.1, 17.1.2 Same as 11.1.2, 17.1.3 Same as 11.1.3, 17.1.4 Same as 11.1.4, 17.1.5 Same as 11.1.5, 17.1.6 Same as 11.1.6, 17.1.7 The average reversed notch impact resistance, J/m (ft·lbf/in.) (see 5.8 for failure categories), 17.1.8 Same as 11.1.8, 17.1.9 Same as 11.1.9, 17.1.10 Same as 11.1.10, and 17.1.11 Same as 11.1.11. 17.1.12 The estimated toss correction, expressed in terms of joule (J) or foot pound-force (ft·lbf). 17.1.13 The difference between the Izod impact energy and the toss correction energy is the net Izod energy. This value is 10

D 256 b 5 192.17 J/m 0.75 mm 5 256.23 J/m of notch per mm of radius

divided by the specimen width (at the base of notch) to obtain the net Izod impact resistance for the report. TEST METHOD D—NOTCH RADIUS SENSITIVITY TEST

24. Report 24.1 Report the following information: 24.1.1 Same as 11.1.1, 24.1.2 Same as 11.1.2, 24.1.3 Same as 11.1.3, 24.1.4 Same as 11.1.4, 24.1.5 Same as 11.1.5, 24.1.6 Same as 11.1.6, 24.1.7 The average reversed notch impact resistance, in J/m (ft·lbf/in.) (see 5.8 for failure categories), 24.1.8 Same as 11.1.8, 24.1.9 Same as 11.1.9, 24.1.10 Same as 11.1.10, and 24.1.11 Same as 11.1.11. 24.1.12 Report the average value of b with its units, and the average Izod impact resistance for a 0.25-mm (0.010-in.) notch.

18. Apparatus 18.1 The apparatus shall be the same as specified in Section 6. 19. Test Specimens 19.1 The test specimens shall be the same as specified in Section 7. All specimens must be of the same nominal width, preferably 6.4-mm (0.25-in.). 20. Notching Test Specimens 20.1 Notching shall be done as specified in Section 8 and Fig. 5, except those ten specimens shall be notched with a radius of 0.25 mm (0.010 in.) and ten specimens with a radius of 1.0 mm (0.040 in.). 21. Conditioning 21.1 Specimen conditioning and test environment shall be in accordance with Section 9.

TEST METHOD E—CANTILEVER BEAM REVERSED NOTCH TEST 25. Apparatus 25.1 The apparatus shall be the same as specified in Section 6.

22. Procedure 22.1 Proceed in accordance with Section 10, testing ten specimens of each notch radius. 22.2 The average impact resistance of each group shall be calculated, except that within each group the type of break must be homogeneously C, H, C and H, or P. 22.3 If the specimens with the 0.25-mm (0.010-in.) radius notch do not break, the test is not applicable. 22.4 If any of ten specimens tested with the 1.0-mm (0.040-in.) radius notch fail as in category NB, non-break, the notch sensitivity procedure cannot be used without obtaining additional data. A new set of specimens should be prepared from the same sample, using a 0.50-mm (0.020-in.) notch radius and the procedure of 22.1 and 22.2 repeated.

26. Test Specimens 26.1 The test specimen shall be the same as specified in Section 7. 27. Notching Test Specimens 27.1 Notch the test specimens in accordance with Section 8. 28. Conditioning 28.1 Specimen conditioning and test environment shall be in accordance with Section 9. 29. Procedure 29.1 Proceed in accordance with Section 10, except clamp the specimen so that the striker impacts it on the face opposite the notch, hence subjecting the notch to compressive rather than tensile stresses during impact (see Fig. 2 and Note 21, Note 22, and Note 23).

23. Calculation 23.1 Calculate the slope of the line connecting the values for impact resistance for 0.25 and 1.0-mm notch radii (or 0.010 and 0.040-in. notch radii) by the equation presented as follows. (If a 0.500-mm (0.020-in.) notch radius is substituted, adjust the calculation accordingly.)

NOTE 21—The reversed notch test employs a standard 0.25-mm (0.010in.) notch specimen to provide an indication of unnotched impact resistance. Use of the reversed notch test obviates the need for machining unnotched specimens to the required 10.2 6 0.05-mm (0.400 6 0.002-in.) depth before testing and provides the same convenience of specimen mounting as the standard notch tests (Test Methods A and C). NOTE 22—Results obtained by the reversed notch test may not always agree with those obtained on unnotched bars that have been machined to the 10.2-mm (0.400-in.) depth requirement. For some materials, the effects arising from the difference in the clamped masses of the two specimen types during test, and those attributable to a possible difference in toss energies ascribed to the broken ends of the respective specimens, may contribute significantly to a disparity in test results. NOTE 23—Where materials are suspected of anisotropy, due to molding or other fabricating influences, notch reversed notch specimens on the face opposite to that used for the standard Izod test; that is, present the same face to the impact blow.

b 5 ~E2 2 E 1!/~R2 2 R1!

where: E 2 = average impact resistance for the larger notch, J/m of notch, E1 = average impact resistance for the smaller notch, J/m of notch, R2 = radius of the larger notch, mm, and R 1 = radius of the smaller notch, mm. Example: E1.0 5 330.95 J/m; E0.25 5 138.78 J/m b 5 ~330.95 2 138.78 J/m!/~1.00 2 0.25 mm!

11

D 256 30. Report 30.1 Report the following information: 30.1.1 Same as 11.1.1, 30.1.2 Same as 11.1.2, 30.1.3 Same as 11.1.3, 30.1.4 Same as 11.1.4, 30.1.5 Same as 11.1.5, 30.1.6 Same as 11.1.6, 30.1.7 The average reversed notch impact resistance, J/m (ft·lbf/in.) (see 5.8 for failure categories), 30.1.8 Same as 11.1.8, 30.1.9 Same as 11.1.9, 30.1.10 Same as 11.1.10, and 30.1.11 Same as 11.1.11.

NOTE 24—Caution: The following explanations of Irand IR (see 31.331.3.3) are only intended to present a meaningful way of considering the precision of this test method. The data in Tables 1-3 should not be rigorously applied to acceptance or rejection of material, as those data are specific to the round robin and may not be representative of other lots, conditions, materials, or laboratories. Users of this test method should apply the principles outlined in Practice E 691 to generate data specific to their laboratory and materials, or between specific laboratories. The principles of 31.3-31.3.3 would then be valid for such data.

31.3 Concept of Ir and IR—If Sr and SR have been calculated from a large enough body of data, and for test results that were averages from testing five specimens. 31.3.1 Repeatability, Ir (Comparing Two Test Results for the Same Material, Obtained by the Same Operator Using the Same Equipment on the Same Day)—The two test results should be judged not equivalent if they differ by more than the Ir value for that material. 31.3.2 Reproducibility, IR (Comparing Two Test Results for the Same Material, Obtained by Different Operators Using Different Equipment on Different Days)—The two test results should be judged not equivalent if they differ by more than the IR value for that material. 31.3.3 Any judgment in accordance with 31.3.1 and 31.3.2 would have an approximate 95 % (0.95) probability of being correct. 31.4 Bias—There is no recognized standards by which to estimate bias of these test methods.

31. Precision and Bias 31.1 Table 1 and Table 2 are based on a round robin10 in accordance with Practice E 691. For each material, all the test bars were prepared at one source, except for notching. Each participating laboratory notched the bars that they tested. Table 1 and Table 2 are presented on the basis of a test result being the average for five specimens. In the round robin each laboratory tested, on average, nine specimens of each material. 31.2 Table 3 is based on a round robin8 involving five materials tested by seven laboratories. For each material, all the samples were prepared at one source, and the individual specimens were all notched at the same laboratory. Table 3 is presented on the basis of a test result being the average for five specimens. In the round robin, each laboratory tested ten specimens of each material. (See Note 24.)

NOTE 25—Numerous changes have occurred since the collection of the original round-robin data in 1973.10 Consequently, a new task group has been formed to evaluate a precision and bias statement for the latest revision of these test methods.

32. Keywords 32.1 impact resistance; Izod impact; notch sensitivity; notched specimen; reverse notch impact

10

Supporting data are available from ASTM Headquarters. Request RR: D201034.

TABLE 2 Precision Data, Test Method C—Reversed Notch Izod

NOTE 1—Values in ft·lbf/in. of width (J/m of width). NOTE 2—See Footnote 10. Material Phenolic

Average

SrA

SRB

IrC

IRD

0.45 (24.0)

0.038 (2.0)

0.129 (6.9)

0.10 (5.3)

0.36 (19.2)

A

Sr = within-laboratory standard deviation of the average. B SR = between-laboratories standard deviation of the average. C Ir = 2.83 Sr. D IR = 2.83 SR.

12

Number of Laboratories 15

D 256 TABLE 3 Precision Data, Test Method E—Reversed Notch Izod

NOTE 1—Values in ft·lbf/in. of width (J/m of width). NOTE 2—See Footnote 8. Material Acrylic sheet, unmodified Premix molding compounds laminate acrylic, injection molded compound (SMC) laminate Preformed mat laminate

SrA

Average 3.02 (161.3) 6.11 (326.3) 10.33 (551.6) 11.00 (587.4) 19.43 (1037.6)

0.243 0.767 0.878 0.719 0.960

(13.0) (41.0) (46.9) (38.4) (51.3)

SRB 0.525 0.786 1.276 0.785 1.618

(28.0) (42.0) (68.1) (41.9) (86.4)

IrC

IRD

0.68 (36.3) 2.17 (115.9) 2.49 (133.0) 2.03 (108.4) 2.72 (145.2)

0.71 (37.9) 2.22 (118.5) 3.61 (192.8) 2.22 (118.5) 4.58 (244.6)

A

Sr = within-laboratory standard deviation of the average. SR = between-laboratories standard deviation of the average. Ir = 2.83 Sr. D IR = 2.83 SR. B

C

ANNEXES (Mandatory Information) A1. INSTRUCTIONS FOR THE CONSTRUCTION OF A WINDAGE AND FRICTION CORRECTION CHART

A1.1 The construction and use of the chart herein described is based upon the assumption that the friction and windage losses are proportional to the angle through which these loss torques are applied to the pendulum. Fig. A1.1 shows the assumed energy loss versus the angle of the pendulum position during the pendulum swing. The correction chart to be described is principally the left half of Fig. A1.1. The windage and friction correction charts should be available from commercial testing machine manufacturers. The energy losses designated as A and B are described in 10.3. A1.2 Start the construction of the correction chart (see Fig. A1.2) by laying off to some convenient linear scale on the abscissa of a graph the angle of pendulum position for the portion of the swing beyond the free hanging position. For convenience, place the free hanging reference point on the right end of the abscissa with the angular displacement increasing linearly to the left. The abscissa is referred to as Scale C. Although angular displacement is the quantity to be represented linearly on the abscissa, this displacement is more conveniently expressed in terms of indicated energy read from the machine dial. This yields a nonlinear Scale C with indicated pendulum energy increasing to the right.

FIG. A1.2 Sample Windage and Friction Correction Chart

starting with zero at the bottom and stopping at the maximum expected pendulum friction and windage value at the top.

A1.3 On the right-hand ordinate lay off a linear Scale B

A1.4 On the left ordinate construct a linear Scale D ranging from zero at the bottom to 1.2 times the maximum ordinate value appearing on Scale B, but make the scale twice the scale used in the construction of Scale B. A1.5 Adjoining Scale D draw a curve OA that is the focus of points whose coordinates have equal values of energy correction on Scale D and indicated energy on Scale C. This curve is referred to as Scale A and utilizes the same divisions and numbering system as the adjoining Scale D. A1.6 Instructions for Using Chart: A1.6.1 Locate and mark on Scale A the reading A obtained from the free swing of the pendulum with the pointer prepositioned in the free hanging or maximum indicated energy position on the dial.

FIG. A1.1 Method of Construction of a Windage and Friction Correction Chart

13

D 256 A1.6.2 Locate and mark on Scale B the reading B obtained after several free swings with the pointer pushed up close to the zero indicated energy position of the dial by the pendulum in accordance with instructions in 10.3. A1.6.3 Connect the two points thus obtained by a straight line.

A1.6.4 From the indicated impact energy on Scale C project up to the constructed line and across to the left to obtain the correction for windage and friction from Scale D. A1.6.5 Subtract this correction from the indicated impact reading to obtain the energy delivered to the specimen.

A2. PROCEDURE FOR THE CALCULATION OF WINDAGE AND FRICTION CORRECTION

A2.1 The procedure for the calculation of the windage and friction correction in this annex is based on the equations developed by derivation in Appendix X3. This procedure can be used as a substitute for the graphical procedure described in Annex A1 and is applicable to small electronic calculator and computer analysis.

hM b max

A2.7 Measure specimen breaking energy, Es, J (ft·lbf).

A2.2 Calculate L, the distance from the axis of support to the center of percussion as indicated in 6.3. (It is assumed here that the center of percussion is approximately the same as the center of gravity.)

A2.8 Calculate b for specimen measurement Es as: b 5 cos 21 $1 2 @~hM/L!~1 2 E s/EM!#%

where: b = angle pendulum travels for a given specimen, and Es = dial reading breaking energy for a specimen, J (ft·lbf).

A2.3 Measure the maximum height, hM, of the center of percussion (center of gravity) of the pendulum at the start of the test as indicated in X2.16. A2.4 Measure and record the energy correction, EA, for windage of the pendulum plus friction in the dial, as determined with the first swing of the pendulum with no specimen in the testing device. This correction must be read on the energy scale, EM, appropriate for the pendulum used.

A2.9 Calculate total correction energy, ETC, as: ETC 5 ~EA 2 ~E B/ 2!!~b/bmax! 1 ~E B/2!

where: ETC = total correction energy for the breaking energy, Es, of a specimen, J (ft·lbf), and = energy correction for windage of the pendulum, J EB (ft·lbf).

A2.5 Without resetting the position of the indicator obtained in A2.4, measure the energy correction, EB , for pendulum windage after two additional releases of the pendulum with no specimen in the testing device. A2.6 Calculate b

max

bmax 5 cos

21

= maximum height of center of gravity of pendulum at start of test, m (ft), and = maximum angle pendulum will travel with one swing of the pendulum.

as follows:

A2.10 Calculate the impact resistance using the following formula:

$1 2 @~hM/L!~1 2 E A/EM!#%

Is 5 ~Es 2 E TC!/t

where: = energy correction for windage of pendulum plus EA friction in dial, J (ft·lbf), = full-scale reading for pendulum used, J (ft·lbf), EM L = distance from fulcrum to center of gravity of pendulum, m (ft),

where: Is = impact resistance of specimen, J/m (ft·lbf/in.) of width, and t = width of specimen or width of notch, m (in.).

14

D 256 APPENDIXES (Nonmandatory Information) X1. PROCEDURE FOR THE INSPECTION AND VERIFICATION OF NOTCH

X1.1 The purpose of this procedure is to describe the microscopic method to be used for determining the radius and angle of the notch. These measurements could also be made using a comparator if available. NOTE X1.1—The notch shall have a radius of 0.25 6 0.05 mm (0.010 6 0.002 in.) and an angle of 45 6 1°.

X1.2 Apparatus: X1.2.1 Optical Device with minimum magnification of 603, Filar glass scale and camera attachment. X1.2.2 Transparent Template, (will be developed in this procedure). X1.2.3 Ruler. X1.2.4 Compass. X1.2.5 Plastic 45°–45°–90° Drafting Set Squares (Triangles). X1.3 A transparent template must be developed for each magnification and for each microscope used. It is preferable that each laboratory standardize on one microscope and one magnification. It is not necessary for each laboratory to use the same magnification because each microscope and camera combination has somewhat different blowup ratios. X1.3.1 Set the magnification of the optical device at a suitable magnification with a minimum magnification of 603. X1.3.2 Place the Filar glass slide on the microscope platform. Focus the microscope so the most distinct image of the Filar scale is visible. X1.3.3 Take a photograph of the Filar scale (see Fig. X1.1). X1.3.4 Create a template similar to that shown in Fig. X1.2. X1.3.4.1 Find the approximate center of the piece of paper. X1.3.4.2 Draw a set of perpendicular coordinates through the center point. X1.3.4.3 Draw a family of concentric circles that are spaced according to the dimensions of the Filar scale.

NOTE 1—Magnification = 100X. FIG. X1.2 Example of Transparent Template for Determining Radius of Notch

X1.3.4.4 This is accomplished by first setting a mechanical compass at a distance of 0.1 mm (0.004 in.) as referenced by the magnified photograph of the Filar eyepiece. Subsequent circles shall be spaced 0.02 mm apart (0.001 in.), as rings with the outer ring being 0.4 mm (0.016 in.) form the center. X1.3.5 Photocopy the paper with the concentric circles to make a transparent template of the concentric circles. X1.3.6 Construct Fig. X1.3 by taking a second piece of paper and find it’s approximate center and mark this point. Draw one line through this center point. Label this line zero degree (0°). Draw a second line perpendicular to the first line through this center point. Label this line “90°.” From the center draw a line that is 44 degrees relative to the “0°.” Label the line “44°.” Draw another line at 46°. Label the line “46°.” X1.4 Place a microscope glass slide on the microscope platform. Place the notched specimen on top of the slide. Focus the microscope. Move the specimen around using the platform adjusting knobs until the specimen’s notch is centered and near the bottom of the viewing area. Take a picture of the notch. X1.4.1 Determination of Notching Radius (see Fig. X1.4): X1.4.1.1 Place the picture on a sheet of paper. Position the picture so that bottom of the notch in the picture faces downwards and is about 64 mm (2.5 in.) from the bottom of the

NOTE 1—100X reference. NOTE 2—0.1 mm major scale; 0.01 mm minor scale. FIG. X1.1 Filar Scale

15

D 256

FIG. X1.3 Example of Transparent Template for Determining Angle of Notch

FIG. X1.4 Determination of Notching Radius

X1.4.2.1 Place transparent template for determining notch angle (see Fig. X1.3) on top of the photograph attached to the sheet of paper. Rotate the picture so that the notch tip is pointed towards you. Position the center point of the template on top of Point I established in 0° axis of the template with the right side straight portion of the notch. Check the left side straight portion of the notch to ensure that this portion falls between the 44 and 46° degree lines. If not, replace the blade.

paper. Tape the picture down to the paper. X1.4.1.2 Draw two lines along the sides of the notch projecting down to a point where they intersect below Notch Point I (see Fig. X1.4). X1.4.1.3 Open the compass to about 51 mm (2 in.). Using Point I as a reference, draw two arcs intersecting both sides of the notch (see Fig. X1.4). These intersections are called 1a and 1b. X1.4.1.4 Close the compass to about 38 mm (1.5 in.). Using Point 1a as the reference point draw an arc (2a) above the notch, draw a second arc (2b) that intersects with arc 2a at Point J. Draw a line between I and J. This establishes the centerline of the notch (see Fig. X1.4). X1.4.1.5 Place the transparent template on top of the picture and align the center of the concentric circles with the drawn centerline of the notch (see Fig. X1.4). X1.4.1.6 Slide the template down the centerline of the notch until one concentric circle touches both sides of the notch. Record the radius of the notch and compare it against the ASTM limits of 0.2 to 0.3 mm (0.008 to 0.012 in.). X1.4.1.7 Examine the notch to ensure that there are no flat spots along the measured radius. X1.4.2 Determination of Notch Angle:

X1.5 A picture of a notch shall be taken at least every 500 notches or if a control sample gives a value outside its three-sigma limits for that test. X1.6 If the notch in the control specimen is not within the requirements, a picture of the notching blade should be taken and analyzed by the same procedure used for the specimen notch. If the notching blade does not meet ASTM requirements or shows damage, it should be replaced with a new blade which has been checked for proper dimensions. X1.7 It is possible that the notching cutter may have the correct dimensions but does not cut the correct notch in the specimen. If that occurs it will be necessary to evaluate other conditions (cutter and feed speeds) to obtain the correct notch dimension for that material.

16

D 256 X2. CALIBRATION OF PENDULUM-TYPE HAMMER IMPACT MACHINES FOR USE WITH PLASTIC SPECIMENS

edge should make contact across the entire width of the bar. If only partial contact is made, examine the vise and pendulum for the cause. If the cause is apparent, make the appropriate correction. If no cause is apparent, remove the striker and shim up or grind its back face to realign the striking edge with the surface of the bar.

X2.1 This calibration procedure applies specifically to the Izod impact machine. However, much of this procedure can be applied to the Charpy impact machine as well. X2.2 Locate the impact machine on a sturdy base. It shall not “walk” on the base and the base shall not vibrate appreciably. Loss of energy from vibrations will give high readings. It is recommended that the impact tester be bolted to a base having a mass of at least 23 kg if it is used at capacities higher than 2.7 J (2 ft·lbf).

X2.10 Check the oil line on the face of the bar for horizontal setting of striking edge within tan−1 0.002 with a machinist’s square. X2.11 Without taking the bar of X2.8 from the vise of the machine, scratch a thin line at the top edge of the vise on the face opposite the striking face of the bar. Remove the bar from the vise and transfer this line to the striking face, using a machinist’s square. The distance from the striking oil line to the top edge of the vise should be 22 6 0.05 mm (0.87 6 0.002 in.). Correct with shims or grinding, as necessary, at the bottom of the vise.

X2.3 Check the level of the machine in both directions in the plane of the base with spirit levels mounted in the base, by a machinist’s level if a satisfactory reference surface is available, or with a plumb bob. The machine should be made level to within tan−1 0.001 in the plane of swing and to within tan −1 0.002 in the plane perpendicular to the swing. X2.4 With a straightedge and a feeler gage or a depth gage, check the height of the movable vise jaw relative to the fixed vise jaw. It must match the height of the fixed vise jaw within 0.08 mm (0.003 in.).

X2.12 When the pendulum is hanging free in its lowest position, the energy reading must be within 0.2 % of full scale. X2.13 Insert the bar of X2.8 into the vise and clamp it tightly in a vertical position. When the striking edge is held in contact with the bar, the energy reading must be within 0.2 % of full scale.

X2.5 Contact the machine manufacturer for a procedure to ensure the striker radius is in tolerance (0.80 6 0.20 mm) (see 6.3). X2.6 Check the transverse location of the center of the pendulum striking edge that shall be within 0.40 mm (0.016 in.) of the center of the vise. Readjust the shaft bearings or relocate the vise, or straighten the pendulum shaft as necessary to attain the proper relationship between the two centers.

X2.14 Swing the pendulum to a horizontal position and support it by the striking edge in this position with a vertical bar. Allow the other end of this bar to rest at the center of a load pan on a balanced scale. Subtract the weight of the bar from the total weight to find the effective weight of the pendulum. The effective pendulum weight should be within 0.4 % of the required weight for that pendulum capacity. If weight must be added or removed, take care to balance the added or removed weight without affecting the center of percussion relative to the striking edge. It is not advisable to add weight to the opposite side of the bearing axis from the striking edge to decrease the effective weight of the pendulum since the distributed mass can lead to large energy losses from vibration of the pendulum.

X2.7 Check the pendulum arm for straightness within 1.2 mm (0.05 in.) with a straightedge or by sighting down the shaft. Allowing the pendulum to slam against the catch sometimes bends the arm especially when high-capacity weights are on the pendulum. X2.8 Insert vertically and center with a locating jig and clamp in the vise a notched machined metal bar 12.7-mm (0.500-in.) square, having opposite sides parallel within 0.025 mm (0.001 in.) and a length of 60 mm (2.4 in.). Check the bar for vertical alignment within tan−1 0.005 in both directions with a small machinist’s level. Shim up the vise, if necessary, to correct for errors in the plane of pendulum swing, using care to preserve solid support for the vise. For errors in the plane perpendicular to the plane of pendulum swing, machine the inside face of the clamp-type locating jig for correct alignment if this type of jig is used. If a blade-type jig is used, use shims or grind the base of the vise to bring the top surface level.

X2.15 Calculate the effective length of the pendulum arm, or the distance to the center of percussion from the axis of rotation, by the procedure in Note 9. The effective length must be within the tolerance stated in 6.3. X2.16 Measure the vertical distance of fall of the pendulum striking edge from its latched height to its lowest point. This distance should be 610 6 2.0 mm (24 6 0.1 in.). This measurement may be made by blocking up a level on the top of the vise and measuring the vertical distance from the striking edge to the bottom of the level (top of vise) and subtracting 22.0 mm (0.9 in.). The vertical falling distance may be adjusted by varying the position of the pendulum latch.

X2.9 Insert and clamp the bar described in X2.8 in a vertical position in the center of the vise so that the notch in the bar is slightly below the top edge of the vise. Place a thin film of oil on the striking edge of the pendulum with an oiled tissue and let the striking edge rest gently against the bar. The striking

X2.17 Notch a standard specimen on one side, parallel to the molding pressure, at 32 mm (1.25 in.) from one end. The 17

D 256 the horizontal and vertical directions within 0.025 mm (0.001 in.). Inserting the machined square metal bar of X2.7 into the vise in a vertical position and clamping until the jaws begin to bind may check parallelism. Any freedom between the metal bar and the clamping surfaces of the jaws of the vise must not exceed the specified tolerance.

depth of the plastic material remaining in the specimen under the notch shall be 10.16 6 0.05 mm (0.400 6 0.002 in.). Use a jig to position the specimen correctly in the vise. When the specimen is clamped in place, the center of the notch should be within 0.12 mm (0.005 in.) of being in line with the top of the fixed surface of the vise and the specimen should be centered midway within 0.40 mm (0.016 in.) between the sides of the clamping faces. The notched face should be the striking face of the specimen for the Izod test. Under no circumstances during the breaking of the specimen should the top of the specimen touch the pendulum except at the striking edge.

X2.23 The top edges of the fixed and moveable jaws of the vise shall have a radius of 0.25 6 0.12 mm (0.010 6 0.005 in.). Depending upon whether Test Method A, C, D, or E is used, a stress concentration may be produced as the specimen breaks. Consequently, the top edge of the fixed and moveable jaw needs to be carefully examined.

X2.18 If a clamping-type locating jig is used, examine the clamping screw in the locating jig. If the thread has a loose fit the specimen may not be correctly positioned and may tend to creep as the screw is tightened. A burred or bent point on the screw may also have the same effect.

X2.24 If a brittle unfilled or granular-filled plastic bar such as a general-purpose wood-flour-filled phenolic material is available, notch and break a set of bars in accordance with these test methods. Examine the surface of the break of each bar in the vise. If the break is flat and smooth across the top surface of the vise, the condition of the machine is excellent. Considerable information regarding the condition of an impact machine can be obtained by examining the broken sections of specimens. No weights should be added to the pendulum for the preceding tests.

X2.19 If a pointer and dial mechanism is used to indicate the energy, the pointer friction should be adjusted so that the pointer will just maintain its position anywhere on the scale. The striking pin of the pointer should be securely fastened to the pointer. Friction washers with glazed surfaces should be replaced with new washers. Friction washers should be on either side of the pointer collar. A heavy metal washer should back the last friction washer installed. Pressure on this metal washer is produced by a thin-bent, spring washer and locknuts. If the spring washer is placed next to the fiber friction washer the pointer will tend to vibrate during impact.

X2.25 The machine should not be used to indicate more than 85 % of the energy capacity of the pendulum. Extra weight added to the pendulum will increase available energy of the machine. This weight must be added so as to maintain the center of percussion within the tolerance stated in 6.3. Correct effective weight for any range can be calculated as follows:

X2.20 The free-swing reading of the pendulum (without specimen) from the latched height should be less than 2.5 % of pendulum capacity on the first swing. If the reading is higher than this, then the friction in the indicating mechanism is excessive or the bearings are dirty. To clean the bearings, dip them in grease solvent and spin-dry in an air jet. Clean the bearings until they spin freely, or replace them. Oil very lightly with instrument oil before replacing. A reproducible method of starting the pendulum from the proper height must be devised.

W 5 Ep/h

where: W = effective pendulum weight, N (lbf) (see X2.13), Ep = potential or available energy of the machine, J (ft·lbf), and h = vertical distance of fall of the pendulum striking edge, m (ft) (see X2.16).

X2.21 The shaft about which the pendulum rotates shall have no detectable radial play (less than 0.05 mm (0.002 in.)). An endplay of 0.25 mm (0.010 in.) is permissible when a 9.8-N (2.2-lbf) axial force is applied in alternate directions.

Each 4.5 N (1 lbf) of added effective weight increases the capacity of the machine by 2.7 J (2 ft·lbf). NOTE X2.1—If the pendulum is designed for use with add-on weight, it is recommended that it be obtained through the equipment manufacturer.

X2.22 The clamping faces of the vise should be parallel in

X3. DERIVATION OF PENDULUM IMPACT CORRECTION EQUATIONS E M 5 hMWpg

X3.1 From right triangle distances in Fig. X3.1: L 2 h 5 L cos b

(X3.1)

X3.5 The potential energy gained by the pendulum, Ep, is related to the absorption of energy of a specimen, E s, by the following equation:

X3.2 But the potential energy gain of pendulum Ep is: Ep 5 hW pg

(X3.2)

EM 2 E s 5 E p

X3.3 Combining Eq X3.1 and Eq X3.2 gives the following: L 2 Ep/Wpg 5 L cos b

(X3.4)

X3.6

(X3.3)

Combining Eq X3.3-X3.5 gives the following: ~EM 2 E s!/EM 5 L/hM ~1 2 cos b!

X3.4 The maximum energy of the pendulum is the potential energy at the start of the test, EM, or

X3.7 Solving Eq X3.6 for b gives the following: 18

(X3.5)

(X3.6)

D 256 EB/2 5 m~0! 1 b

(X3.9)

b 5 EB/2

(X3.10)

or: X3.10 The energy correction, EA, on the first swing of the pendulum occurs at the maximum pendulum angle, bmax. Substituting in Eq X3.8 gives the following: E A 5 mbmax 1 ~EB/2!

(X3.11)

X3.11 Combining Eq X3.8 and Eq X3.11 gives the following: ETC 5 ~EA 2 ~E B/2!!~b/bmax! 1 ~E B/2!

X3.12 Nomenclature:

FIG. X3.1 Swing of Pendulum from Its Rest Position

(X3.7)

b EA

X3.8 From Fig. X3.2, the total energy correction ETC is given as:

EB EM

b 5 cos21$1 2 @~h M/L!~1 2 Es/EM!#%

ETC 5 mb 1 b

X3.9 energy:

(X3.8)

Ep

But at the zero point of the pendulum potential

Es ETC g h hM m L Wp b

FIG. X3.2 Total Energy Correction for Pendulum Windage and Dial Friction as a Function of Pendulum Position

= intercept of total correction energy straight line, = energy correction, including both pendulum windage plus dial friction, J, = energy correction for pendulum windage only, J, = maximum energy of the pendulum (at the start of test), J, = potential energy gain of pendulum from the pendulum rest position, J, = uncorrected breaking energy of specimen, J, = total energy correction for a given breaking energy, E s, J, = acceleration of gravity, m/s2, = distance center of gravity of pendulum rises vertically from the rest position of the pendulum, m, = maximum height of the center of gravity of the pendulum, m, = slope of total correction energy straight line, = distance from fulcrum to center of gravity of pendulum, m, = weight of pendulum, as determined in X2.13, kg, and = angle of pendulum position from the pendulum rest position.

X4. UNIT CONVERSIONS

X4.1 Joules per metre (J/m) cannot be converted directly into kJ/m2. Note that the optional units of kJ/m2 (ft·lbf/in.2) may also be required; therefore, the cross-sectional area under the notch must be reported.

1 ft·lbf/in. 1 ft·lbf/in. 1 ft·lbf/in.

= (39.37)(1.356) J/m = 53.4 J/m = 0.0534 kJ/m

X4.2.2 Example 2: 1 1 1 1

X4.2 The following examples are approximations: X4.2.1 Example 1: 1 ft·lbf/39.37 in.

(X3.12)

= 1.356 J/m

19

ft·lbf/1550 in.2 ft·lbf/in.2 ft·lbf/in.2 ft·lbf/in.2

= 1.356 J/m2 = (1550)(1.356) J/m2 = 2101 J/m2 = 2.1 kJ/m2

D 256 SUMMARY OF CHANGES This section identifies the location of selected changes to these test methods. For the convenience of the user, Committee D20 has highlighted those changes that may impact the use of this test method. This section may also include descriptions of the changes or reasons for the changes, or both. D 256 – 97: (1) Test Method B (Charpy) has been removed from these test methods. This test method is being developed as a separate standard. Research Report D20-1034 will be moved to the new charpy standard. (2) The designations for Test Methods A, C, D, or E remain unchanged due to potential problems with historical data. (3) These test methods have been extensively revised, edito-

rially and technically, with major emphasis on tolerances and units. D 256 – 00: (1) Notch depth dimensions in 8.4, Fig. 5, and X2.17 changed to 10.16 6 0.05 mm. (2) Note 8 added. (3) Deleted former Appendix X4 on Determination of Clamping Load on Izod Specimens.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or [email protected] (e-mail); or through the ASTM website (www.astm.org).

20



Standard Test Method for

Water Absorption of Plastics1 This standard is issued under the fixed designation D 570; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

tics can be made on the basis of values obtained in accordance with 7.1 and 7.4. 3.3 Ideal diffusion of liquids4 into polymers is a function of the square root of immersion time. Time to saturation is strongly dependent on specimen thickness. For example, Table 1 shows the time to approximate time saturation for various thickness of nylon-6. 3.4 The moisture content of a plastic is very intimately related to such properties as electrical insulation resistance, dielectric losses, mechanical strength, appearance, and dimensions. The effect upon these properties of change in moisture content due to water absorption depends largely on the type of exposure (by immersion in water or by exposure to high humidity), shape of the part, and inherent properties of the plastic. With nonhomogeneous materials, such as laminated forms, the rate of water absorption may be widely different through each edge and surface. Even for otherwise homogeneous materials, it may be slightly greater through cut edges than through molded surfaces. Consequently, attempts to correlate water absorption with the surface area must generally be limited to closely related materials and to similarly shaped specimens: For materials of widely varying density, relation between water-absorption values on a volume as well as a weight basis may need to be considered.

1. Scope 1.1 This test method covers the determination of the relative rate of absorption of water by plastics when immersed. This test method is intended to apply to the testing of all types of plastics, including cast, hot-molded, and cold-molded resinous products, and both homogeneous and laminated plastics in rod and tube form and in sheets 0.13 mm (0.005 in.) or greater in thickness. 1.2 The values given in SI units are to be regarded as the standard. The values stated in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. NOTE 1—ISO 62 is technically equivalent to this test method.

2. Referenced Documents 2.1 ASTM Standards: D 647 Practice for Design of Molds for Test Specimens of Plastic Molding Materials2 2.2 ISO Standard: ISO 62 Plastics—Determination of Water Absorption3

4. Apparatus 4.1 Balance—An analytical balance capable of reading 0.0001 g. 4.2 Oven, capable of maintaining uniform temperatures of 50 6 3°C (122 6 5.4°F) and of 105 to 110°C (221 to 230°F).

3. Significance and Use 3.1 This test method for rate of water absorption has two chief functions: first, as a guide to the proportion of water absorbed by a material and consequently, in those cases where the relationships between moisture and electrical or mechanical properties, dimensions, or appearance have been determined, as a guide to the effects of exposure to water or humid conditions on such properties; and second, as a control test on the uniformity of a product. This second function is particularly applicable to sheet, rod, and tube arms when the test is made on the finished product. 3.2 Comparison of water absorption values of various plas-

5. Test Specimen 5.1 The test specimen for molded plastics shall be in the form of a disk 50.8 mm (2 in.) in diameter and 3.2 mm (1⁄8 in.) in thickness (see Note 2). Permissible variations in thickness are 60.18 mm (60.007 in.) for hot-molded and 60.30 mm (60.012 in.) for cold-molded or cast materials. NOTE 2—The disk mold prescribed in the Molds for Disk Test Specimens Section of Practice D 647 is suitable for molding disk test

1 This test method is under the jurisdiction of ASTM Committee D-20 on Plastics and is the direct responsibility of Subcommittee D 20.50 on Permanence Properties. Current edition approved July 10, 1998. Published January 1999. Originally published as D 570 – 40 T. Last previous edition D 570 – 95. 2 Discontinued 1994; replaced by D 1896, D 3419, D 3641, D 4703, and D 5227. See 1994 Annual Book of ASTM Standards, Vol 08.01. 3 Available from American National Standards Institute, 11 W. 42nd St., 13th Floor, New York, NY 10036.

4 Additional information regarding diffusion of liquids in polymers can be found in the following references: (1) Diffusion, Mass Transfer in Fluid Systems, E. L. Cussler, Cambridge University Press, 1985, ISBN 0-521-29846-6, (2) Diffusion in Polymers, J. Crank and G. S. Park, Academic Press, 1968, and (3) “Permeation, Diffusion, and Sorption of Gases and Vapors,” R. M. Felder and G. S. Huvard, in Methods of Experimental Physics, Vol 16C, 1980, Academic Press.

Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.

1

D 570 at 50 6 3°C (122 6 5.4°F), cooled in a desiccator, and immediately weighed to the nearest 0.001 g.

TABLE 1 Time to Saturation for Various Thickness of Nylon-6 Thickness, mm

Typical Time to 95 % Saturation, h

1 2 3.2 10 25

100 400 1 000 10 000 62 000

NOTE 4—If a static charge interferes with the weighing, lightly rub the surface of the specimens with a grounded conductor.

6.1.2 Specimens of materials, such as phenolic laminated plastics and other products whose water-absorption value has been shown not to be appreciably affected by temperatures up to 110°C (230°F), shall be dried in an oven for 1 h at 105 to 110°C (221 to 230°F). 6.1.3 When data for comparison with absorption values for other plastics are desired, the specimens shall be dried in an oven for 24 h at 50 6 3°C (122 6 5.4°F), cooled in a desiccator, and immediately weighed to the nearest 0.001 g.

specimens of thermosetting materials but not thermoplastic materials.

5.2 ISO Standard Specimen—The test specimen for homogeneous plastics shall be 60 by 60 by 1 mm. Tolerance for the 60-mm dimension is 62 mm and 60.05 mm for the 1-mm thickness. This test method and ISO 62 are technically equivalent when the test specimen described in 5.2 is used. 5.3 The test specimen for sheets shall be in the form of a bar 76.2 mm (3 in.) long by 25.4 mm (1 in.) wide by the thickness of the material. When comparison of absorption values with molded plastics is desired, specimens 3.2 mm (1⁄8 in.) thick should be used. Permissible variations in thickness shall be 0.20 mm (60.008 in.) except for asbestos-fabric-base phenolic laminated materials or other materials which have greater standard commercial tolerances. 5.4 The test specimen for rods shall be 25.4 mm (1 in.) long for rods 25.4 mm in diameter or under and 12.7 mm (1⁄2 in.) long for larger-diameter rods. The diameter of the specimen shall be the diameter of the finished rod. 5.5 The test specimen for tubes less than 76 mm (3 in.) in inside diameter shall be the full section of the tube and 25.4 mm (1 in.) long. For tubes 76 mm (3 in.) or more in inside diameter, a rectangular specimen shall be cut 76 mm in length in the circumferential direction of the tube and 25.4 mm in width lengthwise of the tube. 5.6 The test specimens for sheets, rods, and tubes shall be machined, sawed, or sheared from the sample so as to have smooth edges free from cracks. The cut edges shall be made smooth by finishing with No. 0 or finer sandpaper or emery cloth. Sawing, machining, and sandpapering operations shall be slow enough so that the material is not heated appreciably.

7. Procedure 7.1 Twenty-Four Hour Immersion—The conditioned specimens shall be placed in a container of distilled water maintained at a temperature of 23 6 1°C (73.4 6 1.8°F), and shall rest on edge and be entirely immersed. At the end of 24, +1⁄2, −0 h, the specimens shall be removed from the water one at a time, all surface water wiped off with a dry cloth, and weighed to the nearest 0.001 g immediately. If the specimen is 1⁄16 in. or less in thickness, it shall be put in a weighing bottle immediately after wiping and weighed in the bottle. 7.2 Two-Hour Immersion—For all thicknesses of materials having a relatively high rate of absorption, and for thin specimens of other materials which may show a significant weight increase in 2 h, the specimens shall be tested as described in 7.1 except that the time of immersion shall be reduced to 120 6 4 min. 7.3 Repeated Immersion—A specimen may be weighed to the nearest 0.001 g after 2-h immersion, replaced in the water, and weighed again after 24 h. NOTE 5—In using this test method the amount of water absorbed in 24 h may be less than it would have been had the immersion not been interrupted.

7.4 Long-Term Immersion—To determine the total water absorbed when substantially saturated, the conditioned specimens shall be tested as described in 7.1 except that at the end of 24 h they shall be removed from the water, wiped free of surface moisture with a dry cloth, weighed to the nearest 0.001 g immediately, and then replaced in the water. The weighings shall be repeated at the end of the first week and every two weeks thereafter until the increase in weight per two-week period, as shown by three consecutive weighings, averages less than 1 % of the total increase in weight or 5 mg, whichever is greater; the specimen shall then be considered substantially saturated. The difference between the substantially saturated weight and the dry weight shall be considered as the water absorbed when substantially saturated. 7.5 Two-Hour Boiling Water Immersion—The conditioned specimens shall be placed in a container of boiling distilled water, and shall be supported on edge and be entirely immersed. At the end of 120 6 4 min, the specimens shall be removed from the water and cooled in distilled water maintained at room temperature. After 15 6 1 min, the specimens shall be removed from the water, one at a time, all surface water removed with a dry cloth, and the specimens weighed to

NOTE 3—If there is any oil on the surface of the specimen when received or as a result of machining operations, wash the specimen with a cloth wet with gasoline to remove oil, wipe with a dry cloth, and allow to stand in air for 2 h to permit evaporation of the gasoline. If gasoline attacks the plastic, use some suitable solvent or detergent that will evaporate within the 2-h period.

5.7 The dimensions listed in the following table for the various specimens shall be measured to the nearest 0.025 mm (0.001 in.). Dimensions not listed shall be measured within 0.8 mm (61⁄32 in.). Type of Specimen Molded disk Sheet Rod Tube

Dimensions to Be Measured to the Nearest 0.025 mm (0.001 in.) thickness thickness length and diameter inside and outside diameter, and wall thickness

6. Conditioning 6.1 Three specimens shall be conditioned as follows: 6.1.1 Specimens of materials whose water-absorption value would be appreciably affected by temperatures in the neighborhood of 110°C (230°F), shall be dried in an oven for 24 h 2

D 570 Soluble matter lost, % 5 conditioned weight 2 reconditioned weight 3 100 conditioned weight

the nearest 0.001 g immediately. If the specimen is 1⁄16 in. or less in thickness, it shall be weighed in a weighing bottle. 7.6 One-Half-Hour Boiling Water Immersion—For all thicknesses of materials having a relatively high rate of absorption and for thin specimens of other materials which may show a significant weight increase in 1⁄2 h, the specimens shall be tested as described in 7.5, except that the time of immersion shall be reduced to 30 6 1 min. 7.7 Immersion at 50°C—The conditioned specimens shall be tested as described in 7.5, except that the time and temperature of immersion shall be 48 6 1 h and 50 6 1°C (122.0 6 1.8°F), respectively, and cooling in water before weighing shall be omitted. 7.8 When data for comparison with absorption values for other plastics are desired, the 24-h immersion procedure described in 7.1 and the equilibrium value determined in 7.4 shall be used.

NOTE 6—When the weight on reconditioning the specimen after immersion in water exceeds the conditioned weight prior to immersion, report “none” under 9.1.6.

9.1.7 For long-term immersion procedure only, prepare a graph of the increase in weight as a function of the square root of each immersion time. The initial slope of this graph is proportional to the diffusion constant of water in the plastic. The plateau region with little or no change in weight as a function of the square root of immersion time represents the saturation water content of the plastic. NOTE 7—Deviation from the initial slope and plateau model indicates that simple diffusion may be a poor model for determining water content. In such cases, additional studies are suggested to determine a better model for water absorption.

8. Reconditioning 8.1 When materials are known or suspected to contain any appreciable amount of water-soluble ingredients, the specimens, after immersion, shall be weighed, and then reconditioned for the same time and temperature as used in the original drying period. They shall then be cooled in a desiccator and immediately reweighed. If the reconditioned weight is lower than the conditioned weight, the difference shall be considered as water-soluble matter lost during the immersion test. For such materials, the water-absorption value shall be taken as the sum of the increase in weight on immersion and of the weight of the water-soluble matter.

9.1.8 The percentage of water absorbed, which is the sum of the values in 9.1.5 and 9.1.6, and 9.1.9 Any observations as to warping, cracking, or change in appearance of the specimens. 10. Precision and Bias

10.1 Precision—An interlaboratory test program was carried out using the procedure outlined in 7.1, involving three laboratories and three materials. Analysis of this data yields the following coefficients of variation (average of three replicates).

9. Calculation and Report 9.1 The report shall include the values for each specimen and the average for the three specimens as follows: 9.1.1 Dimensions of the specimens before test, measured in accordance with 5.6, and reported to the nearest 0.025 mm (0.001 in.), 9.1.2 Conditioning time and temperature, 9.1.3 Immersion procedure used, 9.1.4 Time of immersion (long-term immersion procedure only), 9.1.5 Percentage increase in weight during immersion, calculated to the nearest 0.01 % as follows: Increase in weight, % 5

5

Average absorption above 1 % (2 materials) Average absorption below 0.2 % (1 material)

Within Laboratories 2.33 %

Between Laboratories 4.89 %

9.01 %

16.63 %

NOTE 8—A round robin is currently under way to more completely determine repeatability and reproducibility of this test method.

10.2 Bias—No justifiable statement on the bias of this test method can be made, since the true value of the property cannot be established by an accepted referee method. 11. Keywords 11.1 absorption; immersion; plastics; water

wet weight 2 conditioned weight 3100 conditioned weight

9.1.6 Percentage of soluble matter lost during immersion, if determined, calculated to the nearest 0.01 % as follows (see Note 6):

5 Supporting data are available from ASTM Headquarters. Request RR: D-201064.

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or [email protected] (e-mail); or through the ASTM website (www.astm.org).

3

LAMPIRAN 2 Tabel.2.1.Data Pengujian Bending Alkali 2 jam Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T1-20/1

20%

Luas (mm )

12

1.35

66

792

B/T1-20/2

13.05

1.35

66

861.3

B/T1-20/3

12.6

1.35

69

869.4

Volume

B/T1-30/1

11.95

1.55

68

812.6

30%

B/T1-30/2

12.95

1.8

69

893.55

B/T1-30/3

12.75

1.7

68

867

Volume

B/T1-40/1

12.7

2.3

67

850.9

40%

B/T1-40/2

12.95

2.25

67

867.65

B/T1-40/3

13.3

2.3

68

904.4

Volume

B/T1-50/1

13.65

1.9

68

928.2

50%

B/T1-50/2

13.05

1.95

68

887.4

B/T1-50/3

12.9

1.9

67

864.3

2

Tebal 2 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T2-20/1

20%

(mm )

12.45

2.1

86

1070.7

B/T2-20/2

12.75

2.1

86

1096.5

B/T2-20/3 B/T2-30/1 B/T2-30/2 B/T2-30/3 B/T2-40/1 B/T2-40/2

12.5 12.7 13.3 12.95 12.55 13.15

2.15 2.8 2.85 2.8 2.75 2.75

86 85 84 86 85 85

1075

B/T2-40/3

12.5

2.7

85

1062.5

Volume

B/T2-50/1

13.2

3.35

85

1122

50%

B/T2-50/2

12.55

3.45

85

1066.75

B/T2-50/3

13.55

3.3

85

1151.75

Volume 30% Volume 40%

Luas 2

1079.5 1117.2 1113.7 1066.75 1117.75

Tebal 3 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T3-20/1

20%

Luas (mm )

14.05

3.15

101

1419.05

B/T3-20/2

15.05

3.2

101

1520.05

B/T3-20/3

12.15

3.15

102

1239.3

Volume

B/T3-30/1

12.65

4.45

100

1265

30%

B/T3-30/2

13.3

4.3

100

1330

B/T3-30/3

11.7

4.2

100

1170

Volume

B/T3-40/1

12.55

3.55

101

1267.55

40%

B/T3-40/2

13.5

3.7

100

1350

B/T3-40/3

14.3

3.7

100

1430

Volume

B/T3-50/1

13.15

4.5

100

1315

50%

B/T3-50/2

13.25

4.2

100

1325

B/T3-50/3

13.15

4.6

100

1315

2

Tebal 4 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T4-20/1

20%

Luas (mm )

13.9

4.4

115

1598.5

B/T4-20/2

12.95

4.25

114

1476.3

B/T4-20/3

13.75

4.2

114

1567.5

Volume

B/T4-30/1

12.7

4.7

114

1447.8

30%

B/T4-30/2

13.3

4.6

114

1516.2

B/T4-30/3

12.65

4.7

115

1454.75

Volume

B/T4-40/1

13.25

5.35

115

1523.75

40%

B/T4-40/2

14.5

5.45

114

1653

B/T4-40/3

13.15

5.55

115

1512.25

Volume

B/T4-50/1

13.3

5.15

115

1529.5

50%

B/T4-50/2

12.6

5.25

115

1449

B/T4-50/3

12.25

5.05

115

1408.75

2

Tebal 5 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T5-20/1

20%

Luas (mm )

14

5.4

130

1820

B/T5-20/2

13

5.45

130

1690

B/T5-20/3

14.85

5.55

130

1930.5

Volume

B/T5-30/1

12.9

5.25

130

1677

30%

B/T5-30/2

12.85

5.4

130

1670.5

B/T5-30/3

12.5

5.25

130

1625

Volume

B/T5-40/1

12.45

6.05

130

1618.5

40%

B/T5-40/2

13.75

5.6

129

1773.75

B/T5-40/3

12.8

5.75

130

1664

Volume

B/T5-50/1

13

7.05

130

1690

50%

B/T5-50/2

12.4

7

130

1612

B/T5-50/3

13.15

6.8

131

1722.65

Luas (mm2)

2

Alkali 4 jam Tebal 1 mm Jenis

No

Lebar

Tebal

komposit

Spesimen

(mm)

(mm)

Panjang Awal (mm)

Volume

B/T1-20/1

12

1.35

66

792

20%

B/T1-20/2

13.05

1.35

66

861.3

B/T1-20/3

12.6

1.35

69

869.4

Volume

B/T1-30/1

11.95

1.55

68

812.6

30%

B/T1-30/2

12.95

1.8

69

893.55

B/T1-30/3

12.75

1.7

68

867

Volume

B/T1-40/1

12.7

2.3

67

850.9

40%

B/T1-40/2

12.95

2.25

67

867.65

B/T1-40/3

13.3

2.3

68

904.4

Volume

B/T1-50/1

13.65

1.9

68

928.2

50%

B/T1-50/2

13.05

1.95

68

887.4

B/T1-50/3

12.9

1.9

67

864.3

Tebal 2 mm Jenis

No

Lebar

Tebal

Panjang Awal (mm)

komposit

Spesimen

(mm)

(mm)

Volume

B/T2-20/1

12.45

20%

B/T2-20/2

(mm )

2.1

86

1070.7

12.75

2.1

86

1096.5

B/T2-20/3 B/T2-30/1 B/T2-30/2 B/T2-30/3 B/T2-40/1 B/T2-40/2

12.5 12.7 13.3 12.95 12.55 13.15

2.15 2.8 2.85 2.8 2.75 2.75

86 85 84 86 85 85

1075

B/T2-40/3

12.5

2.7

85

1062.5

Volume

B/T2-50/1

13.2

3.35

85

1122

50%

B/T2-50/2

12.55

3.45

85

1066.75

B/T2-50/3

13.55

3.3

85

1151.75


Luas 2

1079.5 1117.2 1113.7 1066.75 1117.75

Tebal 3 mm Jenis

No

Lebar

Tebal

Panjang Awal (mm)

Luas

komposit

Spesimen

(mm)

(mm)

Volume

B/T3-20/1

14.05

3.15

101 1419.05

20%

B/T3-20/2

15.05

3.2

101 1520.05

B/T3-20/3

12.15

3.15

102

1239.3

Volume

B/T3-30/1

12.65

4.45

100

1265

30%

B/T3-30/2

13.3

4.3

100

1330

B/T3-30/3

11.7

4.2

100

1170

Volume

B/T3-40/1

12.55

3.55

40%

B/T3-40/2

13.5

3.7

100

1350

B/T3-40/3

14.3

3.7

100

1430

Volume

B/T3-50/1

13.15

4.5

100

1315

50%

B/T3-50/2

13.25

4.2

100

1325

B/T3-50/3

13.15

4.6

100

1315

2

(mm )

101 1267.55

Tebal 4 mm Jenis

No

Lebar

Tebal

Panjang Awal (mm)

komposit

Spesimen

(mm)

(mm)

Volume

B/T4-20/1

13.9

20%

B/T4-20/2

Luas (mm )

4.4

115

1598.5

12.95

4.25

114

1476.3

B/T4-20/3

13.75

4.2

114

1567.5

Volume

B/T4-30/1

13.3

5.15

115

1529.5

30%

B/T4-30/2

12.6

5.25

115

1449

B/T4-30/3

12.25

5.05

115

1408.75

Volume

B/T4-40/1

13.25

5.35

115

1523.75

40%

B/T4-40/2

14.5

5.45

114

1653

B/T4-40/3

13.15

5.55

115

1512.25

Volume

B/T4-50/1

12.7

4.7

114

1447.8

50%

B/T4-50/2

13.3

4.6

114

1516.2

B/T4-50/3

12.65

4.7

115

1454.75

2

Tebal 5 mm Jenis

No

Lebar

Tebal

Panjang Awal (mm)

komposit

Spesimen

(mm)

(mm)

Volume

B/T5-20/1

14

20%

B/T5-20/2

Luas (mm )

5.4

130

1820

13

5.45

130

1690

B/T5-20/3

14.85

5.55

130

1930.5

Volume

B/T5-30/1

12.9

5.25

130

1677

30%

B/T5-30/2

12.85

5.4

130

1670.5

B/T5-30/3

12.5

5.25

130

1625

Volume

B/T5-40/1

13

7.05

130

1690

40%

B/T5-40/2

12.4

7

130

1612

B/T5-40/3

13.15

6.8

131

1722.65

Volume

B/T5-50/1

12.45

6.05

130

1618.5

50%

B/T5-50/2

13.75

5.6

129

1773.75

B/T5-50/3

12.8

5.75

130

1664

2


No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T1-20/1

20%

Luas (mm )

12

1.35

66

792

B/T1-20/2

13.05

1.35

66

861.3

B/T1-20/3

12.6

1.35

69

869.4

Volume

B/T1-30/1

11.95

1.55

68

812.6

30%

B/T1-30/2

12.95

1.8

69

893.55

B/T1-30/3

12.75

1.7

68

867

Volume

B/T1-40/1

12.7

2.3

67

850.9

40%

B/T1-40/2

12.95

2.25

67

867.65

B/T1-40/3

13.3

2.3

68

904.4

Volume

B/T1-50/1

13.65

1.9

68

928.2

50%

B/T1-50/2

13.05

1.95

68

887.4

B/T1-50/3

12.9

1.9

67

864.3

Panjang Awal (mm)

Luas (mm )

2

Tebal 2 mm Jenis

No

Lebar

Tebal

komposit

Spesimen

(mm)

(mm)

Volume

B/T2-20/1

12.45

2.1

86

1070.7

20%

B/T2-20/2

12.75

2.1

86

1096.5

B/T2-20/3 B/T2-30/1 B/T2-30/2 B/T2-30/3 B/T2-40/1 B/T2-40/2

12.5 12.7 13.3 12.95 12.55 13.15

2.15 2.8 2.85 2.8 2.75 2.75

86 85 84 86 85 85

1075

B/T2-40/3

12.5

2.7

85

1062.5

Volume

B/T2-50/1

13.2

3.35

85

1122

50%

B/T2-50/2

12.55

3.45

85

1066.75

B/T2-50/3

13.55

3.3

85

1151.75


2

1079.5 1117.2 1113.7 1066.75 1117.75

Tebal 3 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T3-20/1

20%

Luas (mm )

14.05

3.15

101

1419.05

B/T3-20/2

15.05

3.2

101

1520.05

B/T3-20/3

12.15

3.15

102

1239.3

Volume

B/T3-30/1

12.65

4.45

100

1265

30%

B/T3-30/2

13.3

4.3

100

1330

B/T3-30/3

11.7

4.2

100

1170

Volume

B/T3-40/1

12.55

3.55

101

1267.55

40%

B/T3-40/2

13.5

3.7

100

1350

B/T3-40/3

14.3

3.7

100

1430

Volume

B/T3-50/1

13.15

4.5

100

1315

50%

B/T3-50/2

13.25

4.2

100

1325

B/T3-50/3

13.15

4.6

100

1315

Luas (mm )

2

Tebal 4 mm Jenis

No

Lebar

Tebal

komposit

Spesimen

(mm)

(mm)

Panjang Awal (mm)

Volume

B/T4-20/1

13.9

4.4

115

1598.5

20%

B/T4-20/2

12.95

4.25

114

1476.3

B/T4-20/3

13.75

4.2

114

1567.5

Volume

B/T4-30/1

12.7

4.7

114

1447.8

30%

B/T4-30/2

13.3

4.6

114

1516.2

B/T4-30/3

12.65

4.7

115

1454.75

Volume

B/T4-40/1

13.25

5.35

115

1523.75

40%

B/T4-40/2

14.5

5.45

114

1653

B/T4-40/3

13.15

5.55

115

1512.25

Volume

B/T4-50/1

13.3

5.15

115

1529.5

50%

B/T4-50/2

12.6

5.25

115

1449

B/T4-50/3

12.25

5.05

115

1408.75

2

Tebal 5 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Luas (mm )

2

Volume

B/T5-20/1

14

5.4

130

1820

20%

B/T5-20/2

13

5.45

130

1690

B/T5-20/3

14.85

5.55

130

1930.5

Volume

B/T5-30/1

12.9

5.25

130

1677

30%

B/T5-30/2

12.85

5.4

130

1670.5

B/T5-30/3

12.5

5.25

130

1625

Volume

B/T5-40/1

12.45

6.05

130

1618.5

40%

B/T5-40/2

13.75

5.6

129

1773.75

B/T5-40/3

12.8

5.75

130

1664

Volume

B/T5-50/1

13

7.05

130

1690

50%

B/T5-50/2

12.4

7

130

1612

B/T5-50/3

13.15

6.8

131

1722.65

Luas (mm )


No

Lebar

Tebal

komposit

Spesimen

(mm)

(mm)

Panjang Awal (mm)

Volume

B/T1-20/1

12

1.35

66

792

20%

B/T1-20/2

13.05

1.35

66

861.3

B/T1-20/3

12.6

1.35

69

869.4

Volume

B/T1-30/1

11.95

1.55

68

812.6

30%

B/T1-30/2

12.95

1.8

69

893.55

B/T1-30/3

12.75

1.7

68

867

Volume

B/T1-40/1

12.7

2.3

67

850.9

40%

B/T1-40/2

12.95

2.25

67

867.65

B/T1-40/3

13.3

2.3

68

904.4

Volume

B/T1-50/1

13.65

1.9

68

928.2

50%

B/T1-50/2

13.05

1.95

68

887.4

B/T1-50/3

12.9

1.9

67

864.3

2

Tebal 2 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T2-20/1

20%

(mm )

12.45

2.1

86

1070.7

B/T2-20/2

12.75

2.1

86

1096.5

B/T2-20/3 B/T2-30/1 B/T2-30/2 B/T2-30/3 B/T2-40/1 B/T2-40/2

12.5 12.7 13.3 12.95 12.55 13.15

2.15 2.8 2.85 2.8 2.75 2.75

86 85 84 86 85 85

1075

B/T2-40/3

12.5

2.7

85

1062.5

Volume

B/T2-50/1

13.2

3.35

85

1122

50%

B/T2-50/2

12.55

3.45

85

1066.75

B/T2-50/3

13.55

3.3

85

1151.75

Panjang Awal (mm)

Luas


Luas 2

1079.5 1117.2 1113.7 1066.75 1117.75

Tebal 3 mm Jenis

No

Lebar

Tebal

komposit

Spesimen

(mm)

(mm)

Volume

B/T3-20/1

14.05

3.15

101

1419.05

20%

B/T3-20/2

15.05

3.2

101

1520.05

B/T3-20/3

12.15

3.15

102

1239.3

Volume

B/T3-30/1

12.65

4.45

100

1265

30%

B/T3-30/2

13.3

4.3

100

1330

B/T3-30/3

11.7

4.2

100

1170

Volume

B/T3-40/1

12.55

3.55

101

1267.55

40%

B/T3-40/2

13.5

3.7

100

1350

B/T3-40/3

14.3

3.7

100

1430

Volume

B/T3-50/1

13.15

4.5

100

1315

50%

B/T3-50/2

13.25

4.2

100

1325

B/T3-50/3

13.15

4.6

100

1315

2

(mm )

Tebal 4 mm Jenis

No

Lebar

Tebal (mm)

Panjang Awal (mm)

komposit

Spesimen

(mm)

Volume

B/T4-20/1

20%

Luas (mm )

13.9

4.4

115

1598.5

B/T4-20/2

12.95

4.25

114

1476.3

B/T4-20/3

13.75

4.2

114

1567.5

Volume

B/T4-30/1

12.7

4.7

114

1447.8

30%

B/T4-30/2

13.3

4.6

114

1516.2

B/T4-30/3

12.65

4.7

115

1454.75

Volume

B/T4-40/1

13.25

5.35

115

1523.75

40%

B/T4-40/2

14.5

5.45

114

1653

B/T4-40/3

13.15

5.55

115

1512.25

Volume

B/T4-50/1

13.3

5.15

115

1529.5

50%

B/T4-50/2

12.6

5.25

115

1449

B/T4-50/3

12.25

5.05

115

1408.75

Panjang Awal (mm)

Luas (mm )

2

Tebal 5 mm Jenis

No

Lebar

Tebal

komposit

Spesimen

(mm)

(mm)

Volume

B/T5-20/1

14

5.4

130

1820

20%

B/T5-20/2

13

5.45

130

1690

B/T5-20/3

14.85

5.55

130

1930.5

Volume

B/T5-30/1

12.9

5.25

130

1677

30%

B/T5-30/2

12.85

5.4

130

1670.5

B/T5-30/3

12.5

5.25

130

1625

Volume

B/T5-40/1

12.45

6.05

130

1618.5

40%

B/T5-40/2

13.75

5.6

B/T5-40/3

12.8

5.75

130

1664

Volume

B/T5-50/1

13

7.05

130

1690

50%

B/T5-50/2

12.4

7

130

1612

B/T5-50/3

13.15

6.8

2

129 1773.75

131 1722.65

Tabel.2.2.Data Pengujian Tarik Alkali 2 jam

Specimen 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

40% T2

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

panjang awal 33 32 33 31 32 33 31 32 33 31 31 32 32.5 32 33 33.5 34 33 32 33 31.7 32.5 32.6 32.5 33 34 33.5 32 31.8 32.2 33.5 33 31.6 32 32 33.6 33 34

lebar

tebal

G (Kgf)

ε (mm)

luas

6 6.5 7 6 6 7 7 6.5 6.5 6 7 7 6 6.5 6.4 6 5.9 5 6 6.5 7 6.8 6 5.5 6.5 6.2 6 7 6.3 7 7 6.3 5.8 5.5 6 5.4 6 6.5

1.35 1.35 1.35 1.55 1.8 1.7 1.6 1.5 1.5 1.9 1.95 1.9 2.5 2 2.4 2.8 2.5 2.4 2.2 2.4 2.5 2.3 2.4 2.4 3.2 3 3 3.5 3.5 2.8 3 3.4 3 3.4 3.2 3.4 4.4 3.8

15.11 17.26 10.01 2.82 18.81 28.49 24.74 18.97 15.48 45.98 18.77 28.49 25.65 30.55 28.33 42.30 38.76 34.10 74.55 38.35 45.52 60.54 84.13 48.84 62.75 43.72 34.46 80.07 64.64 55.89 66.77 108.96 114.68 127.86 125.02 80.02 98.43 77.49

0.71 1.25 0.61 0.57 0.81 1.09 0.62 1.12 0.78 0.83 0.73 1.09 0.42 0.43 0.39 0.43 0.48 0.59 0.60 0.50 0.42 0.52 0.75 0.46 0.58 0.32 0.26 0.79 0.41 0.30 0.54 0.77 0.08 0.64 0.86 0.44 0.86 0.89

198 208 231 186 192 231 217 208 214.5 186 217 224 195 208 211.2 201 200.6 165 192 214.5 221.9 221 195.6 178.75 214.5 210.8 201 224 200.34 225.4 234.5 207.9 183.28 176 192 181.44 198 221

30% T4

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

32.5 31.8 32 32 32.6 33.2 33.4 33 32 33.4 33 32.5 32.6 33 32 34 33 32.8 33.5 33.2 34 33.5

6 7 6.5 7 6 7 6.3 6.5 7 7 7 7 6.5 6.4 6 6 6.4 6.5 7 6.8 6.4 6

4.2 3.9 4.2 4.5 4 4.6 4.8 3.5 4.2 4.5 4.8 5 5.4 6 5.5 4.8 5 5.2 5.5 6 6.2 5.5

94.56 91.53 77.80 78.77 127.72 137.73 125.54 319.83 172.29 309.66 163.42 209.19 200.10 136.29 248.40 127.59 158.43 251.41 224.02 257.15 220.72 345.19

0.78 0.79 0.55 0.59 1.28 1.29 1.21 1.48 0.88 1.49 1.59 1.39 1.36 1.49 1.52 1.61 1.43 1.49 1.53 1.68 1.63 1.25

195 222.6 208 224 195.6 232.4 210.42 214.5 224 233.8 231 227.5 211.9 211.2 192 204 211.2 213.2 234.5 225.76 217.6 201

panjang awal 33.5 33 32 31 32 33 31 32 33 31 32 32 32 32 33 33 34 33

lebar

tebal

G (Kgf)

ε (mm)

luas

6.5 6.5 7 6 6 7 7 6.5 6 6 7 6.5 6 6.5 6.4 6 5.9 5

1.35 1.35 1.35 1.55 1.8 1.7 1.6 1.5 1.5 1.9 1.95 1.9 2.5 2 2.4 2.8 2.5 2.4

13.70 14.79 25.21 11.47 15.48 20.55 38.86 38.82 40.79 27.27 30.18 35.88 60.34 36.52 13.32 52.00 20.76 23.57

1.86 0.85 0.73 0.73 0.78 0.85 0.94 1.19 1.88 0.57 0.78 0.91 0.61 0.39 1.40 1.00 1.21 1.10

217.75 214.5 224 186 192 231 217 208 198 186 224 208 192 208 211.2 198 200.6 165

Alkali 4 jam Specimen 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

40% T2

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

30% T4

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

32 33 32 32.5 32 33 33 32 33 32 31.8 32.2 32 33 31.6 32 32 32 33 33 32.5 31.8 32 32 32.6 33.2 33.4 33 32 32 33 32 32 33 32 34 33 32.8 32 33.2 33 32

6 6.5 7 6.5 6 5.5 6.5 6.2 6 7 6.3 7 7 6.3 6 5.5 6 5.4 6 6.5 6 7 6.5 6.5 6 7 6.3 6.5 7 7 6.5 7 6.5 6.4 6 6 6.4 6.5 7 6.8 6.4 6

2.2 2.4 2.5 2.3 2.4 2.4 3.2 3 3 3.5 3.5 2.8 3 3.4 3 3.4 3.2 3.4 4.4 3.8 4.2 3.9 4.2 4.5 4 4.6 4.8 3.5 4.2 4.5 4.8 5 5.4 6 5.5 4.8 5 5.2 5.5 6 6.2 5.5

94.98 65.43 50.86 103.69 91.18 89.72 43.55 46.90 85.45 82.52 82.76 85.17 56.49 60.89 79.80 155.46 144.68 119.87 66.35 71.89 112.86 82.94 103.34 135.73 120.04 102.73 90.39 178.03 157.93 135.01 58.43 68.37 70.40 77.97 81.95 120.52 111.37 102.96 115.76 233.21 202.29 180.90

0.85 0.59 0.56 0.71 0.77 0.57 0.33 0.32 0.58 0.65 0.68 0.58 0.34 0.48 0.86 1.04 0.81 0.54 0.35 0.53 0.61 0.60 0.57 0.86 0.68 0.60 0.37 1.29 0.65 0.60 0.57 0.36 0.34 0.37 0.45 0.56 0.47 0.71 0.55 1.14 0.67 0.66

192 214.5 224 211.25 192 181.5 214.5 198.4 198 224 200.34 225.4 224 207.9 189.6 176 192 172.8 198 214.5 195 222.6 208 208 195.6 232.4 210.42 214.5 224 224 214.5 224 208 211.2 192 204 211.2 213.2 224 225.76 211.2 192

Alkali 6 jam Specimen 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

40% T2

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

30% T4

panjang awal 33.5 33 32 31 32 33 31 32 33 31 32 32 32 32 33 33 34 33 32 33 32 32.5 32 33 33 32 33 32 31.8 32.2 32 33 31.6 32 32 32 33 33 32.5 31.8

lebar

tebal

G (Kgf)

ε (mm)

luas

6 6 6.5 6 6 6.5 7 6.5 6 6 7 6 6.5 6 6 6 5.9 5.5 6 6.5 7 6.5 6 7 6.5 6.2 6 7 6.5 7 7 6.5 6 6 6 5.8 6.5 6 6 7

1.35 1.35 1.35 1.55 1.8 1.7 1.6 1.5 1.5 1.9 1.95 1.9 2.5 2 2.4 2.8 2.5 2.4 2.2 2.4 2.5 2.3 2.4 2.4 3.2 3 3 3.5 3.5 2.8 3 3.4 3 3.4 3.2 3.4 4.4 3.8 4.2 3.9

12.59 9.31 15.46 24.29 21.44 17.57 34.45 33.09 21.19 40.85 56.25 47.83 32.35 49.06 31.11 30.48 45.75 40.18 139.26 92.20 72.02 120.13 90.28 125.17 60.03 49.56 61.05 76.84 83.30 62.99 132.56 96.43 88.11 116.83 153.67 121.47 71.09 65.62 73.81 99.75

0.85 0.47 0.77 0.80 1.45 0.79 0.58 1.21 1.48 0.60 0.72 1.07 0.69 0.58 1.01 0.72 0.19 0.87 0.83 0.56 0.55 1.18 0.88 0.95 0.75 0.39 0.48 0.42 0.62 0.40 1.00 0.70 0.61 0.63 0.80 0.68 0.38 0.48 0.53 0.58

201 198 208 186 192 214.5 217 208 198 186 224 192 208 192 198 198 200.6 181.5 192 214.5 224 211.25 192 231 214.5 198.4 198 224 206.7 225.4 224 214.5 189.6 192 192 185.6 214.5 198 195 222.6

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

32 32 32.6 33.2 33.4 33 32 32 33 32 32 33 32 34 33 32.8 32 33.2 33 32

6.5 6 6 7 6.3 6.5 7 7 6 6.5 6 6.5 6 6 6.5 6.5 7 6.8 6.5 7

4.2 4.5 4 4.6 4.8 3.5 4.2 4.5 4.8 5 5.4 6 5.5 4.8 5 5.2 5.5 6 6.2 5.5

114.03 124.88 180.71 112.29 129.32 111.72 106.23 144.42 64.43 118.95 78.69 130.66 108.82 125.92 125.79 159.07 144.85 207.68 186.31 291.33

0.54 0.61 1.04 0.56 0.78 0.54 0.52 0.75 0.42 0.59 0.48 0.57 0.64 0.62 0.83 0.92 0.86 0.87 0.64 1.15

208 192 195.6 232.4 210.42 214.5 224 224 198 208 192 214.5 192 204 214.5 213.2 224 225.76 214.5 224

panjang awal 33.5 33 32 31 32 33 31 32 33 31 32 32 32 32 33 33 34 33 32 33

lebar

tebal

G (Kgf)

ε (mm)

luas

6 6 6.5 6 6 6.5 7 6.5 6 6 7 6 6.5 6 6 6 5.9 5.5 6 6.5

1.35 1.35 1.35 1.55 1.8 1.7 1.6 1.5 1.5 1.9 1.95 1.9 2.5 2 2.4 2.8 2.5 2.4 2.2 2.4

10.27 13.35 13.81 30.63 19.22 23.46 34.70 11.78 25.72 45.01 33.42 29.98 14.72 35.54 37.12 55.00 41.10 38.10 89.79 74.64

0.50 0.70 0.90 0.67 0.79 0.51 0.92 1.16 0.88 0.73 0.48 0.42 1.25 0.37 0.60 0.55 0.49 0.48 0.59 0.46

201 198 208 186 192 214.5 217 208 198 186 224 192 208 192 198 198 200.6 181.5 192 214.5

Alkali 8 jam Alkali 8 jam 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

40% T2

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

30% T4

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

32 32.5 32 33 33 32 33 32 31.8 32.2 32 33 31.6 32 32 32 33 33 32.5 31.8 32 32 32.6 33.2 33.4 33 32 32 33 32 32 33 32 34 33 32.8 32 33.2 33 32

7 6.5 6 7 6.5 6.2 6 7 6.5 7 7 6.5 6 6 6 5.8 6.5 6 6 7 6.5 6 6 7 6.3 6.5 6.4 6.5 6 6.5 6 6.5 6 6 6.5 6.5 7 6 6.5 6

2.5 2.3 2.4 2.4 3.2 3 3 3.5 3.5 2.8 3 3.4 3 3.4 3.2 3.4 4.4 3.8 4.2 3.9 4.2 4.5 4 4.1 4.2 4 4.2 4.5 4.8 5 5.4 6 5.5 4.8 5 5.2 5.5 5.5 5 5

68.48 80.15 84.61 78.18 45.11 71.02 50.15 84.17 71.81 65.18 98.74 82.27 91.63 143.88 161.82 144.87 73.54 61.84 70.59 78.84 92.61 89.34 135.75 131.02 103.38 196.27 286.62 159.26 131.07 99.55 114.77 108.42 128.26 141.13 195.08 164.91 166.88 134.14 166.02 143.77

0.58 0.50 0.52 0.68 0.35 0.47 0.77 0.75 0.56 0.47 0.78 0.56 0.56 0.81 0.90 0.79 0.47 0.48 0.39 0.48 0.58 0.57 0.63 0.62 0.45 1.06 1.52 0.87 0.50 0.41 0.49 0.45 0.53 0.62 0.81 0.73 0.62 0.75 0.71 0.60

224 211.25 192 231 214.5 198.4 198 224 206.7 225.4 224 214.5 189.6 192 192 185.6 214.5 198 195 222.6 208 192 195.6 232.4 210.42 214.5 204.8 208 198 208 192 214.5 192 204 214.5 213.2 224 199.2 214.5 192

Tabel.2.3.Data Pengujian Impak Alkali 2 jam Jenis komposit

No Spesimen

Tebal (mm)

Lebar (mm)

Luas penampang dibawah takik (mm²)

Harga impak (J/mm²)

Volume

I/T1-20/1

1.25

4.55

5.69

0.4

20%

I/T1-20/2

1.3

4.35

5.66

0.4

I/T1-20/3

1.2

5.05

6.06

0.5

Volume

I/T1-30/1

1.25

5.5

6.88

0.5

30%

I/T1-30/2

1.55

5.7

8.84

0.4

I/T1-30/3

1.5

5.75

8.63

0.5

Volume

I/T1-40/1

2.15

5.75

12.36

0.6

40%

I/T1-40/2

2.15

4.85

10.43

0.6

I/T1-40/3

2.15

4.9

10.54

0.7

Volume

I/T1-50/1

1.95

4.55

8.87

0.8

50%

I/T1-50/2

2.2

5.65

12.43

0.7

I/T1-50/3

1.7

5.1

8.67

0.7

Volume

I/T2-20/1

2.1

4.8

10.08

0.8

20%

I/T2-20/2

2.1

5.3

11.13

1

I/T2-20/3

2.1

5.1

10.71

0.8

Volume

I/T2-30/1

2.55

6.15

15.68

0.8

30%

I/T2-30/2

2.6

6.15

15.99

0.7

I/T2-30/3

2.65

5.85

15.50

0.8

Volume

I/T2-40/1

2.95

5.2

15.34

0.7

40%

I/T2-40/2

2.8

5.5

15.40

0.5

I/T2-40/3

3

5.95

17.85

0.6

Volume

I/T2-50/1

3.55

5.25

18.64

1

50%

I/T2-50/2

3.75

5.25

19.69

0.9

I/T2-50/3

3.75

5.2

19.50

1

Volume

I/T3-20/1

3.3

5.35

17.66

1

20%

I/T3-20/2

3.15

5.25

16.54

1.1

I/T3-20/3

3.2

4.95

15.84

1.1

Volume

I/T3-30/1

4.15

5.15

21.37

1.2

30%

I/T3-30/2

3.3

5.4

17.82

1.1

I/T3-30/3

3.4

5.05

17.17

1.1

Volume

I/T3-40/1

4.1

5.4

22.14

1.1

40%

I/T3-40/2

3.05

5.5

16.78

1.1

I/T3-40/3

4.05

5.15

20.86

1.3

Volume

I/T3-50/1

4.35

4.95

21.53

1

50%

I/T3-50/2

4.2

5.3

22.26

1.1

I/T3-50/3

3.8

5.8

22.04

1.1

Volume

I/T4-20/1

3.95

4.95

19.55

1.4

20%

I/T4-20/2

4.05

5.25

21.26

1.4

I/T4-20/3

4.05

5.1

20.66

1.5

Volume

I/T4-30/1

4.5

6

27.00

1.1

30%

I/T4-30/2

4.4

5.35

23.54

1.1

I/T4-30/3

4.2

5.65

23.73

1.2

Volume

I/T4-40/1

4.4

5.85

25.74

1.2

40%

I/T4-40/2

4.1

6.2

25.42

1.3

I/T4-40/3

3.95

6.35

25.08

1.3

Volume

I/T4-50/1

4.75

5.95

28.26

1.5

50%

I/T4-50/2

4.2

5.55

23.31

1.6

I/T4-50/3

4.5

4.45

20.03

1.4

Volume

I/T5-20/1

5.2

5.7

29.64

1.7

20%

I/T5-20/2

5.4

5.3

28.62

1.7

I/T5-20/3

5

5.25

26.25

1.6

Volume

I/T5-30/1

5.3

5.55

29.42

1.6

30%

I/T5-30/2

5.5

4.9

26.95

1.7

I/T5-30/3

5.2

5.15

26.78

1.6

Volume

I/T5-40/1

5.4

5.2

28.08

1.7

40%

I/T5-40/2

5.1

5.25

26.78

1.8

I/T5-40/3

5.2

5.75

29.90

1.7

Volume

I/T5-50/1

5.1

5.5

28.05

1.8

50%

I/T5-50/2

5

5.55

27.75

1.7

I/T5-50/3

5

6

30

1.6

Alkali 4 jam Jenis komposit

No Spesimen

Tebal (mm)

Lebar (mm)



Volume

I/T1-20/1

1

5

6.24

0.5

20%

I/T1-20/2

1.25

4.55

5.69

0.6

I/T1-20/3

1.2

5.05

6.06

0.4

Volume

I/T1-30/1

1.25

5.5

6.88

0.5

30%

I/T1-30/2

1.55

5.7

8.84

0.5

I/T1-30/3

1.5

5.75

8.63

0.6

Volume

I/T1-40/1

2.15

5.75

12.36

0.7

40%

I/T1-40/2

2.15

4.85

10.43

0.6

I/T1-40/3

2.15

4.9

10.54

0.7

Volume

I/T1-50/1

1.95

4.55

8.87

0.8

50%

I/T1-50/2

2.2

5.65

12.43

0.7

I/T1-50/3

1.7

5.1

8.67

0.8

Volume

I/T2-20/1

2.1

4.8

10.08

0.8

20%

I/T2-20/2

2.1

5.3

11.13

0.8

I/T2-20/3

2.1

5.1

10.71

0.9

Volume

I/T2-30/1

2.55

6.15

15.68

0.9

30%

I/T2-30/2

2.6

6.15

15.99

0.8

I/T2-30/3

2.65

5.85

15.50

0.7

Volume

I/T2-40/1

2.95

5.2

15.34

0.8

40%

I/T2-40/2

2.8

5.5

15.40

0.7

I/T2-40/3

3

5.95

17.85

0.6

Volume

I/T2-50/1

3.55

5.25

18.64

0.9

50%

I/T2-50/2

3.75

5.25

19.69

1

I/T2-50/3

3.75

5.2

19.50

1.1

Volume

I/T3-20/1

3.3

5.35

17.66

1.1

20%

I/T3-20/2

3.15

5.25

16.54

1.1

I/T3-20/3

3.2

4.95

15.84

1.2

Volume

I/T3-30/1

4.15

5.15

21.37

1.3

30%

I/T3-30/2

3.3

5.4

17.82

1.1

I/T3-30/3

3.4

5.05

17.17

1.3

I/T3-40/1

4.1

5.4

22.14

1.1

Volume

40%

I/T3-40/2

3.05

5.5

16.78

1

I/T3-40/3

4.05

5.15

20.86

1.1

Volume

I/T3-50/1

4.35

4.95

21.53

1.4

50%

I/T3-50/2

4.2

5.3

22.26

1.4

I/T3-50/3

3.8

5.8

22.04

1.5

Volume

I/T4-20/1

3.95

4.95

19.55

1.5

20%

I/T4-20/2

4.05

5.25

21.26

1.4

I/T4-20/3

4.05

5.1

20.66

1.5

Volume

I/T4-30/1

4.5

6

27.00

1.1

30%

I/T4-30/2

4.4

5.35

23.54

1.3

I/T4-30/3

4.2

5.65

23.73

1.3

Volume

I/T4-40/1

4.4

5.85

25.74

1.4

40%

I/T4-40/2

4.1

6.2

25.42

1.6

I/T4-40/3

3.95

6.35

25.08

1.6

Volume

I/T4-50/1

4.75

5.95

28.26

1.7

50%

I/T4-50/2

4.2

5.55

23.31

1.5

I/T4-50/3

4.5

4.45

20.03

1.5

Volume

I/T5-20/1

5.2

5.7

29.64

1.4

20%

I/T5-20/2

5.4

5.3

28.62

1.5

I/T5-20/3

5

5.25

26.25

1.5

Volume

I/T5-30/1

5.3

5.55

29.42

1.5

30%

I/T5-30/2

5.5

4.9

26.95

1.7

I/T5-30/3

5.2

5.15

26.78

1.7

Volume

I/T5-40/1

5.4

5.2

28.08

1.8

40%

I/T5-40/2

5.1

5.25

26.78

1.7

I/T5-40/3

5.2

5.75

29.90

1.8

Volume

I/T5-50/1

5.1

5.5

28.05

1.8

50%

I/T5-50/2

5

5.55

27.75

1.7

I/T5-50/3

5

6

30

1.8


No Spesimen

Tebal (mm)

Lebar (mm)



Volume

I/T1-20/1

1

5

6.24

0.6

20%

I/T1-20/2

1.25

4.55

5.69

0.5

I/T1-20/3

1.2

5.2

6.24

0.5

Volume

I/T1-30/1

1.25

5.5

6.88

0.6

30%

I/T1-30/2

1.55

5.7

8.84

0.5

I/T1-30/3

1.5

5.75

8.63

0.4

Volume

I/T1-40/1

2.15

5.75

12.36

0.5

40%

I/T1-40/2

1.75

4.85

8.49

0.6

I/T1-40/3

1.95

4.9

9.56

0.6

Volume

I/T1-50/1

1.95

4.55

8.87

0.6

50%

I/T1-50/2

2.1

5.65

11.87

0.8

I/T1-50/3

1.7

5.1

8.67

0.7

Volume

I/T2-20/1

2.1

4.8

10.08

0.9

20%

I/T2-20/2

2.1

5.3

11.13

0.8

I/T2-20/3

2.1

5.1

10.71

1

Volume

I/T2-30/1

2.55

6.15

15.68

0.7

30%

I/T2-30/2

2.6

6.15

15.99

0.8

I/T2-30/3

2.65

5.85

15.50

0.7

Volume

I/T2-40/1

2.95

5.2

15.34

0.7

40%

I/T2-40/2

2.8

5.5

15.40

0.8

I/T2-40/3

2.7

5.95

16.07

0.9

Volume

I/T2-50/1

2.85

5.25

14.96

1.1

50%

I/T2-50/2

2.55

5.25

13.39

1.1

I/T2-50/3

2.56

5.2

13.31

1.2

Volume

I/T3-20/1

3.3

5.35

17.66

1

20%

I/T3-20/2

3.15

5.25

16.54

1.1

I/T3-20/3

3.2

4.95

15.84

0.9

Volume

I/T3-30/1

4.15

5.15

21.37

1.2

30%

I/T3-30/2

3.3

5.4

17.82

1.3

I/T3-30/3

3.4

5.05

17.17

1.3

I/T3-40/1

4.1

5.4

22.14

1.3

Volume

40%

I/T3-40/2

3.05

5.5

16.78

1.3

I/T3-40/3

4.05

5.15

20.86

1.2

Volume

I/T3-50/1

4.35

4.95

21.53

1.4

50%

I/T3-50/2

4.2

5.3

22.26

1.3

I/T3-50/3

3.8

5.8

22.04

1.3

Volume

I/T4-20/1

3.95

4.95

19.55

1.3

20%

I/T4-20/2

4.05

5.25

21.26

1.2

I/T4-20/3

4.05

5.1

20.66

1.2

Volume

I/T4-30/1

4.5

6

27.00

1.3

30%

I/T4-30/2

4.4

5.35

23.54

1.2

I/T4-30/3

4.2

5.65

23.73

1.3

Volume

I/T4-40/1

4.4

5.85

25.74

1.6

40%

I/T4-40/2

4.1

6.2

25.42

1.5

I/T4-40/3

3.95

6.35

25.08

1.5

Volume

I/T4-50/1

4.75

5.95

28.26

1.8

50%

I/T4-50/2

4.2

5.55

23.31

1.7

I/T4-50/3

4.5

4.45

20.03

1.7

Volume

I/T5-20/1

5.2

5.7

29.64

1.7

20%

I/T5-20/2

5.4

5.3

28.62

1.5

I/T5-20/3

5

5.25

26.25

1.5

Volume

I/T5-30/1

5.3

5.55

29.42

1.6

30%

I/T5-30/2

5.5

4.9

26.95

1.7

I/T5-30/3

5.2

5.15

26.78

1.7

Volume

I/T5-40/1

5.4

5.2

28.08

1.7

40%

I/T5-40/2

5.1

5.25

26.78

1.6

I/T5-40/3

5.2

5.75

29.90

1.8

Volume

I/T5-50/1

5.1

5.5

28.05

1.8

50%

I/T5-50/2

5.4

5.55

29.97

1.8

I/T5-50/3

5

5.65

28.25

1.9


No Spesimen

Tebal (mm)

Lebar (mm)



Volume

I/T1-20/1

1.50

5.25

7.88

0.4

20%

I/T1-20/2

1.25

4.85

6.06

0.6

I/T1-20/3

1.2

5.40

6.48

0.6

Volume

I/T1-30/1

1.25

5.5

6.88

0.4

30%

I/T1-30/2

1.55

5.7

8.84

0.6

I/T1-30/3

1.5

5.75

8.63

0.6

Volume

I/T1-40/1

2.15

5.75

12.36

0.6

40%

I/T1-40/2

1.75

4.85

8.49

0.7

I/T1-40/3

1.95

4.9

9.56

0.5

Volume

I/T1-50/1

1.95

4.55

8.87

0.8

50%

I/T1-50/2

2.10

5.65

11.87

0.9

I/T1-50/3

1.7

5.1

8.67

0.7

Volume

I/T2-20/1

2.1

4.80

10.08

0.7

20%

I/T2-20/2

2.1

5.3

11.13

0.9

I/T2-20/3

2.1

5.1

10.71

0.9

Volume

I/T2-30/1

2.55

6.15

15.68

0.8

30%

I/T2-30/2

2.6

6.15

15.99

1.1

I/T2-30/3

2.65

5.85

15.50

1

Volume

I/T2-40/1

2.95

5.2

15.34

0.9

40%

I/T2-40/2

2.8

5.5

15.40

0.8

I/T2-40/3

2.70

5.95

16.07

0.6

Volume

I/T2-50/1

2.85

5.25

14.96

1

50%

I/T2-50/2

2.55

5.25

13.39

0.9

I/T2-50/3

2.56

5.2

13.31

0.9

Volume

I/T3-20/1

3.3

5.35

17.66

1.1

20%

I/T3-20/2

3.15

5.25

16.54

1.1

I/T3-20/3

3.2

4.95

15.84

1.2

Volume

I/T3-30/1

4.15

5.15

21.37

1.1

30%

I/T3-30/2

3.3

5.4

17.82

1.2

I/T3-30/3

3.4

5.05

17.17

1.2

I/T3-40/1

4.1

5.4

22.14

1.2

Volume

40%

I/T3-40/2

3.05

5.5

16.78

1.3

I/T3-40/3

4.05

5.15

20.86

1.2

Volume

I/T3-50/1

4.35

4.95

21.53

1.4

50%

I/T3-50/2

4.2

5.3

22.26

1.3

I/T3-50/3

3.8

5.8

22.04

1.4

Volume

I/T4-20/1

3.95

4.95

19.55

1.2

20%

I/T4-20/2

4.05

5.25

21.26

1.1

I/T4-20/3

4.05

5.1

20.66

1.1

Volume

I/T4-30/1

4.5

6.00

27.00

1.4

30%

I/T4-30/2

4.4

5.35

23.54

1.5

I/T4-30/3

4.2

5.65

23.73

1.4

Volume

I/T4-40/1

4.4

5.85

25.74

1.5

40%

I/T4-40/2

4.1

6.2

25.42

1.4

I/T4-40/3

3.95

6.35

25.08

1.4

Volume

I/T4-50/1

4.75

5.95

28.26

1.8

50%

I/T4-50/2

4.2

5.55

23.31

1.6

I/T4-50/3

4.5

4.45

20.03

1.7

Volume

I/T5-20/1

5.2

5.7

29.64

1.6

20%

I/T5-20/2

5.4

5.3

28.62

1.7

I/T5-20/3

5.00

5.25

26.25

1.6

Volume

I/T5-30/1

5.3

5.55

29.42

1.7

30%

I/T5-30/2

5.5

4.9

26.95

1.6

I/T5-30/3

5.2

5.15

26.78

1.5

Volume

I/T5-40/1

5.4

5.2

28.08

1.8

40%

I/T5-40/2

5.1

5.25

26.78

1.7

I/T5-40/3

5.2

5.75

29.90

1.5

Volume

I/T5-50/1

5.1

5.00

25.50

1.9

50%

I/T5-50/2

5.25

5.45

28.61

1.7

I/T5-50/3

5.20

5.50

28.6

1.6

LAMPIRAN III

1. Pengujian Bending (Standart ASTM D 790-02) Diketahui : Tebal spesimen (d)

: 1,35 mm

Lebar spesimen (b)

: 12,00 mm

Panjang span (L)

: 25,4 mm

Gaya (P)

: 0,05 kN = 50 N

Penambahan panjang (∆L mesin)

: 4,68 mm

a. Defleksi

 

Lmesin kotak

4,68mm  0,78 mm (nilai per kotak) 6kotak

= 2,5 kotak x 0,78 = 1,95 mm

b. Momen bending P

L P/2

Mb = =

P/2

½L

PL 4

50 N  25,4mm 4mm

=317,5 N

c. Tegangan bending

 

3PL 2bd 2 3  50 N  25,4mm

2  12 mm  1,35 mm 

2



3810 N .mm 43,74 mm 3

= 87,1056 N/mm2

d. Modulus elastisitas bending

PL3 E 4bd 3



50N  (25,4mm) 3

4  12mm  1,35mm  1,95mm 3

819353 ,2 N .mm 3  230 ,2911 mm 5

= 3557,902 N/mm2 e. Kekakuan bending (Lukasen, 1975) I

= 1/12 x b x h3 = 1/12 x 12 mm x (1,35 mm)3 = 2,460 mm4

D =ExI = 3557,902N/mm2 x 2,460 mm4 = 8753,773 Nmm2

2. Pengujian Impak (Standart ASTM D 256-00) Diketahui : Tebal spesimen (d)

: 1,25mm

Lebar spesimen (b)

: 4,55mm

Luas (Ao)

: 5,7 mm2

Energi Terpasang

: 21 J

Sudut α

: 300

Sudut β

: 29,50

Panjang Lengan (R)

: 0,8 m : 10 m/s2

Percepatan gravitasi (g) Berat Pendulum (m) a. Esrp

: 20 kg

= mg.R.(cos β - cos α) = 20kg. 10 m/s2 0,8 m(cos 29,5- cos 30) = 160 kgm2/s2 (0,87-0,866) = 0,69 kgm2/s2= 0,7 J

b. HI

=

Eserap Ao

=

0,7 J 5,7 mm 2

= 0,122 J/mm2

3. Pengujian Tarik ( Standart ASTM D 638-02) Diketahui : Tebal spesimen (d)

: 1,35mm

Lebar spesimen (b)

: 6 mm

Panjang specimen (lo)

: 33 mm

Luas

(A)

: 198 mm2

Beban

(P)

:148,10 N

Regangan

()

:0,71 mm/mm

a. Tegangan Tarik P= σ . A atau σ = P/A =148,10 N / 198 mm2

=0,748 Mpa b. Regangan Tarik 

=

L atau ΔL = x lo lo = 0,71 x 33 =23,43 mm

c. Modulus elastisitas tarik E

 =  = 0,748 Mpa / 0,71 mm/mm =1,048 Mpa.

Data Hasil Pengujian Impak Serat Rami Alkali 2 jam Jenis komposit

No Spesimen


Harga impak rata-rata (j/mm²)

Energi yang terserap (J)

Volume

I/T1-20/1

0.4

20%

I/T1-20/2

0.4

I/T1-20/3

0.5

Volume

I/T1-30/1

0.5

30%

I/T1-30/2

0.4

I/T1-30/3

0.5

4.31

Volume

I/T1-40/1

0.6

7.42

40%

I/T1-40/2

0.6

I/T1-40/3

0.7

7.37

Volume

I/T1-50/1

0.8

7.10

50%

I/T1-50/2

0.7

Energi yang terserap rata-rata (J)

2.28 0.433

2.26

2.522

3.03 3.44 0.467

0.700

0.733

3.53

6.26

8.70

I/T1-50/3

0.7

6.07

Volume

I/T2-20/1

0.8

8.06

20%

I/T2-20/2

1

I/T2-20/3

0.8

8.57

Volume

I/T2-30/1

0.8

12.55

30%

I/T2-30/2

0.7

I/T2-30/3

0.8

12.40

Volume

I/T2-40/1

0.7

10.74

40%

I/T2-40/2

0.5

I/T2-40/3

0.6

10.71

Volume

I/T2-50/1

1

18.64

50%

I/T2-50/2

0.9

I/T2-50/3

1

19.50

Volume

I/T3-20/1

1

17.66

20%

I/T3-20/2

1.1

I/T3-20/3

1.1

Volume

I/T3-30/1

1.2

30%

I/T3-30/2

1.1

I/T3-30/3

1.1

18.89

Volume

I/T3-40/1

1.1

24.35

40%

I/T3-40/2

1.1

I/T3-40/3

1.3

0.867

0.767

0.600

0.967

1.067

11.13

11.19

7.70

17.72

18.19

3.761

7.016

7.289

9.254

12.047

9.716

18.619

17.757

17.42 25.65 1.133

1.167

19.60

18.45 27.11

21.379

23.307

Volume

I/T3-50/1

1

21.53

50%

I/T3-50/2

1.1

I/T3-50/3

1.1

24.24

Volume

I/T4-20/1

1.4

27.37

20%

I/T4-20/2

1.4

I/T4-20/3

1.5

30.98

Volume

I/T4-30/1

1.1

29.70

30%

I/T4-30/2

1.1

I/T4-30/3

1.2

Volume

I/T4-40/1

1.2

40%

I/T4-40/2

1.3

I/T4-40/3

1.3

32.61

Volume

I/T4-50/1

1.5

42.39

50%

I/T4-50/2

1.6

I/T4-50/3

1.4

28.04

Volume

I/T5-20/1

1.7

50.39

20%

I/T5-20/2

1.7

1.067

1.433

1.133

24.49

29.77

25.89

23.421

29.375

28.023

28.48 30.89 1.267

1.500

1.667

33.05

37.30

48.65

I/T5-20/3

1.6

42.00

Volume

I/T5-30/1

1.6

47.06

30%

I/T5-30/2

1.7

I/T5-30/3

1.6

42.85

Volume

I/T5-40/1

1.7

47.74

40%

I/T5-40/2

1.8

I/T5-40/3

1.7

50.83

Volume

I/T5-50/1

1.8

50.49

50%

I/T5-50/2

1.7

I/T5-50/3

1.6

1.633

1.733

1.700

45.82

48.20

47.18

32.180

35.908

47.014

45.242

48.920

48.555

48.00


No Spesimen




Volume

I/T1-20/1

0.5

20%

I/T1-20/2

0.6

I/T1-20/3

0.4

3.03

Volume

I/T1-30/1

0.5

3.44

30%

I/T1-30/2

0.5

I/T1-30/3

0.6


3.12 0.500

0.533

3.41

4.42 5.18

3.188

4.343

Volume

I/T1-40/1

0.7

8.65

40%

I/T1-40/2

0.6

I/T1-40/3

0.7

7.37

Volume

I/T1-50/1

0.8

7.10

50%

I/T1-50/2

0.7

I/T1-50/3

0.8

6.94

Volume

I/T2-20/1

0.8

8.06

20%

I/T2-20/2

0.8

I/T2-20/3

0.9

Volume

I/T2-30/1

0.9

30%

I/T2-30/2

0.8

I/T2-30/3

0.7

10.85

Volume

I/T2-40/1

0.8

12.27

40%

I/T2-40/2

0.7

I/T2-40/3

0.6

10.71

Volume

I/T2-50/1

0.9

16.77

50%

I/T2-50/2

1

0.700

0.767

0.833

6.26

8.70

8.90

7.428

7.578

8.869

9.64 14.11 0.800

0.700

1.000

12.79

10.78

19.69

I/T2-50/3

1.1

21.45

Volume

I/T3-20/1

1.1

19.42

20%

I/T3-20/2

1.1

I/T3-20/3

1.2

19.01

Volume

I/T3-30/1

1.3

27.78

30%

I/T3-30/2

1.1

I/T3-30/3

1.3

22.32

Volume

I/T3-40/1

1.1

24.35

40%

I/T3-40/2

1

1.133

1.233

1.067

18.19

19.60

16.78

I/T3-40/3

1.1

22.94

Volume

I/T3-50/1

1.4

30.15

50%

I/T3-50/2

1.4

I/T3-50/3

1.5

33.06

Volume

I/T4-20/1

1.5

29.33

20%

I/T4-20/2

1.4

I/T4-20/3

1.5

30.98

Volume

I/T4-30/1

1.1

29.70

30%

I/T4-30/2

1.3

I/T4-30/3

1.3

30.85

Volume

I/T4-40/1

1.4

36.04

40%

I/T4-40/2

1.6

I/T4-40/3

1.6

40.13

Volume

I/T4-50/1

1.7

48.05

50%

I/T4-50/2

1.5

1.433

1.467

1.233

1.533

1.567

31.16

29.77

30.60

40.67

34.97

12.586

11.254

19.304

18.873

23.236

21.357

31.457

30.026

30.384

38.947

37.683

I/T4-50/3

1.5

30.04

Volume

I/T5-20/1

1.4

20%

I/T5-20/2

1.5

I/T5-20/3

1.5

39.38

Volume

I/T5-30/1

1.5

44.12

30%

I/T5-30/2

1.7

I/T5-30/3

1.7

45.53

Volume

I/T5-40/1

1.8

50.54

40%

I/T5-40/2

1.7

41.50 1.467

1.633

1.767

42.93

45.82

45.52

I/T5-40/3

1.8

53.82

Volume

I/T5-50/1

1.8

50.49

50%

I/T5-50/2

1.7

I/T5-50/3

1.8

1.767

47.18

41.267

45.155

49.961

50.555

54.00


No Spesimen




Volume

I/T1-20/1

0.6

20%

I/T1-20/2

0.5

I/T1-20/3

0.5

3.03

Volume

I/T1-30/1

0.6

4.13

30%

I/T1-30/2

0.5

I/T1-30/3

0.4

3.45

Volume

I/T1-40/1

0.5

6.18

40%

I/T1-40/2

0.6

3.74 0.533

0.500

0.600

2.84

4.42

5.09

I/T1-40/3

0.6

5.73

Volume

I/T1-50/1

0.6

5.32

50%

I/T1-50/2

0.8

I/T1-50/3

0.7

6.07

Volume

I/T2-20/1

0.9

9.07

20%

I/T2-20/2

0.8

I/T2-20/3

1

10.71

Volume

I/T2-30/1

0.7

10.98

30%

I/T2-30/2

0.8

I/T2-30/3

0.7

10.85

I/T2-40/1

0.7

10.74

Volume


0.700

0.900

0.733

9.49

8.90

12.79

3.206

3.998

5.669

6.962

9.562

11.541

40%

I/T2-40/2

0.8

0.800

12.32

I/T2-40/3

0.9

14.46

Volume

I/T2-50/1

1.1

16.46

50%

I/T2-50/2

1.1

I/T2-50/3

1.2

15.97

Volume

I/T3-20/1

1

17.66

20%

I/T3-20/2

1.1

I/T3-20/3

0.9

14.26

Volume

I/T3-30/1

1.2

25.65

30%

I/T3-30/2

1.3

I/T3-30/3

1.3

22.32

Volume

I/T3-40/1

1.3

28.78

40%

I/T3-40/2

1.3

I/T3-40/3

1.2

25.03

Volume

I/T3-50/1

1.4

30.15

50%

I/T3-50/2

1.3

I/T3-50/3

1.3

Volume

I/T4-20/1

1.3

20%

I/T4-20/2

1.2

I/T4-20/3

1.2

24.79

Volume

I/T4-30/1

1.3

35.10

30%

I/T4-30/2

1.2

I/T4-30/3

1.3

30.85

Volume

I/T4-40/1

1.6

41.18

40%

I/T4-40/2

1.5

I/T4-40/3

1.5

Volume

I/T4-50/1

1.8

50%

I/T4-50/2

1.7

I/T4-50/3

1.7

34.04

Volume

I/T5-20/1

1.7

50.39

20%

I/T5-20/2

1.5

I/T5-20/3

1.5

39.38

Volume

I/T5-30/1

1.6

47.06

30%

I/T5-30/2

1.7

1.133

1.000

1.267

1.267

1.333

14.73

18.19

23.17

21.81

28.94

12.506

15.720

16.701

23.711

25.206

29.245

28.65 25.42 1.233

1.267

1.533

25.52

28.25

38.13

25.240

31.399

38.979

37.62 50.87 1.733

1.567

1.667

39.63

42.93

45.82

I/T5-30/3

1.7

45.53

Volume

I/T5-40/1

1.7

47.74

40%

I/T5-40/2

1.6

I/T5-40/3

1.8

53.82

Volume

I/T5-50/1

1.8

50.49

50%

I/T5-50/2

1.8

I/T5-50/3

1.9

1.700

1.833

42.84

53.95 53.68

41.514

44.231

46.135

48.132

52.704


No Spesimen


Volume

I/T1-20/1

0.4

20%

I/T1-20/2

0.6




3.15 0.533

3.64

I/T1-20/3

0.6

3.03

Volume

I/T1-30/1

0.4

2.75

30%

I/T1-30/2

0.6

I/T1-30/3

0.6

5.18

Volume

I/T1-40/1

0.6

7.42

40%

I/T1-40/2

0.7

I/T1-40/3

0.5

4.78

Volume

I/T1-50/1

0.8

7.10

50%

I/T1-50/2

0.9

I/T1-50/3

0.7

6.07

Volume

I/T2-20/1

0.7

7.06

20%

I/T2-20/2

0.9

I/T2-20/3

0.9

9.64

Volume

I/T2-30/1

0.8

12.55

30%

I/T2-30/2

1.1

I/T2-30/3

1

Volume

I/T2-40/1

0.9

40%

I/T2-40/2

0.8

I/T2-40/3

0.6

9.64

Volume

I/T2-50/1

1

14.96

50%

I/T2-50/2

0.9

I/T2-50/3

0.9

11.98

Volume

I/T3-20/1

1.1

19.42

20%

I/T3-20/2

1.1

0.533

0.667

0.800

0.833

0.967

5.30

5.94

10.68

10.02

17.59

3.273

4.409

6.045

7.949

8.904

15.213

15.50 13.81 0.767

0.933

1.133

12.32

12.05

18.19

I/T3-20/3

1.2

19.01

Volume

I/T3-30/1

1.1

23.51

30%

I/T3-30/2

1.2

I/T3-30/3

1.2

20.60

Volume

I/T3-40/1

1.2

26.57

40%

I/T3-40/2

1.3

I/T3-40/3

1.2

25.03

Volume

I/T3-50/1

1.4

30.15

50%

I/T3-50/2

1.3

1.167

1.233

1.367

21.38

21.81

28.94

11.922

12.997

18.873

21.833

24.468

29.980

I/T3-50/3

1.4

30.86

Volume

I/T4-20/1

1.2

20%

I/T4-20/2

1.1

I/T4-20/3

1.1

22.72

Volume

I/T4-30/1

1.4

37.80

30%

I/T4-30/2

1.5

I/T4-30/3

1.4

33.22

Volume

I/T4-40/1

1.5

38.61

40%

I/T4-40/2

1.4

23.46 1.133

1.433

1.433

23.39

35.31

35.59

I/T4-40/3

1.4

35.12

Volume

I/T4-50/1

1.8

50.87

50%

I/T4-50/2

1.6

I/T4-50/3

1.7

34.04

Volume

I/T5-20/1

1.6

47.42

20%

I/T5-20/2

1.7

I/T5-20/3

1.6

42.00

Volume

I/T5-30/1

1.7

50.01

30%

I/T5-30/2

1.6

I/T5-30/3

1.5

40.17

Volume

I/T5-40/1

1.8

50.54

40%

I/T5-40/2

1.7

I/T5-40/3

1.5

44.85

Volume

I/T5-50/1

1.9

48.45

50%

I/T5-50/2

1.7

I/T5-50/3

1.6

1.700

1.633

1.600

1.667

1.733

37.30

48.65

43.12

45.52

48.64 45.76

23.191

35.444

36.438

40.737

46.026

44.432

46.971

47.617

Data Hasil Pengujian tarik Serat Rami Alkali 2 jam specimen 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

40% T2

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

kek tarik

Mod Elastisitas

kek tarik rata2

Mod Elastisitas rata2

0.748

1.048

0.662

0.797

0.813

0.650

0.425

0.694

0.148

0.260

0.772

0.850

0.960

1.182

1.209

1.107

1.117

1.814

0.906

1.174

0.894

0.801

0.707

0.907

2.423

2.937

1.506

1.747

0.848

1.163

1.247

1.142

1.289

3.106

1.348

3.297

1.439

3.370

1.314

3.414

2.062

4.774

1.994

4.060

1.894

3.962

2.025

3.444

3.805

6.300

2.523

4.875

1.752

3.504

2.010

4.821

2.685

5.173

3.192

5.565

4.215

5.650

2.678

5.872

2.867

4.952

2.193

5.924

2.032

6.432

1.680

6.389

3.503

4.462

3.032

6.756

3.162

7.731

2.430

8.074

2.790

5.158

4.686

28.560

5.136

6.644

6.132

73.879

7.120

11.055

5.941

9.449

6.381

7.403

4.322

9.890

4.872

5.685

4.353

5.208

3.436

3.878

4.752

6.061

30% T4

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

4.030

5.114

3.666

6.702

3.446

5.881

6.399

5.011

5.808

4.520

5.847

4.816

14.612

9.880

7.538

8.615

12.980

8.711

6.933

4.352

9.011

6.506

9.254

6.795

6.324

4.241

12.679

8.325

6.129

3.819

7.351

5.148

11.556

7.756

9.362

6.119

11.162

6.652

9.940

6.098

16.830

13.442

3.714

5.899

6.018

4.782

11.710

9.069

8.399

5.884

8.377

5.462

9.423

6.341

12.644

8.731

Data Hasil Pengujian tarik Serat Rami Alkali 4 jam Spesimen 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

kek tarik

Mod Elastisitas

kek tarik rata2


0.617

0.331

0.798

0.878

0.676

0.793

1.103

1.511

0.604

0.829

0.755

0.956

0.790

1.013

0.872

1.026

1.755

1.877

1.868

1.498

1.829

1.541

2.019

1.077

1.437

2.525

1.483

2.025

1.320

1.693

1.690

1.858

3.080

5.082

1.806

3.308

1.721

4.401

0.618

0.442

2.574

2.579

1.663

1.563

1.014

0.839

40% T2

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

30% T4

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

1.400

1.272

4.848

5.677

2.989

5.084

2.225

4.002

4.810

6.737

4.654

6.013

4.844

8.559

1.990

6.122

2.316

7.307

4.229

7.356

3.610

5.529

4.049

5.945

3.703

6.352

2.471

7.377

2.870

5.979

4.125

4.791

8.656

8.316

7.385

9.128

6.798

12.613

3.284

9.409

3.285

6.163

5.672

9.252

3.651

6.096

4.869

8.587

6.395

7.471

6.014

8.884

4.332

7.280

4.210

11.503

8.134

6.315

6.910

10.581

5.907

9.861

2.669

4.675

2.991

8.403

3.317

9.901

3.618

9.884

4.183

9.254

5.789

10.265

5.168

10.949

4.732

6.637

5.065

9.142

10.123

8.857

9.386

13.927

9.234

13.948

3.354

4.921

4.769

7.103

2.845

6.928

3.787

5.942

3.155

6.049

7.613

10.019

4.080

8.275

4.972

7.385

4.852

9.222

6.983

8.919

2.992

7.659

4.530

9.801

4.988

8.909

9.581

12.244

Data Hasil Pengujian tarik Serat Rami Alkali 6 jam Specimen 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

40% T2

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

30% T4

kek tarik

Mod Elastisitas

kek tarik rata2


0.614

0.723

0.601

0.886

0.461

0.986

0.728

0.948

1.280

1.608

1.059

1.128

1.094

0.756

0.803

1.021

1.556

2.701

1.388

1.568

1.559

1.293

1.049

0.710

2.152

3.587

2.352

3.096

2.461

3.418

2.441

2.282

1.524

2.222

1.856

2.700

2.504

4.347

1.540

1.531

1.508

2.110

1.971

5.536

2.235

12.017

2.169

2.482

7.108

8.616

4.824

7.293

4.212

7.482

3.151

5.782

5.573

4.743

5.164

5.205

4.608

5.266

5.310

5.608

2.743

3.657

2.738

5.420

2.448

6.359

3.022

6.243

3.362

7.947

3.350

7.040

3.950

6.360

2.739

6.812

5.800

5.782

4.920

6.533

4.406

6.339

4.554

7.478

5.963

9.421

6.740

9.554

7.843

9.780

6.414

9.460

3.248

8.615

3.402

7.451

3.248

6.753

3.709

6.985

4.391

7.598

5.379

9.314

5.373

9.913

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

6.374

10.432

9.054

8.731

4.735

8.456

6.023

7.682

5.104

9.453

4.647

8.886

6.319

8.414

3.189

7.593

5.604

9.499

4.016

8.420

5.970

10.473

5.554

8.679

6.049

9.804

5.747

6.949

7.312

7.939

6.337

7.343

9.015

10.398

8.512

13.404

12.746

11.112

6.604

8.290

5.357

8.917

4.270

8.504

5.858

9.652

6.465

7.410

10.091

11.638

Data Hasil Pengujian tarik Serat Rami Alkali 8 jam Alkali 8 jam 20% T1

30% T1

40% T1

50% T1

20% T2

30% T2

40% T2

kek tarik

Mod Elastisitas

kek tarik rata2


0.501

1.011

0.604

0.895

0.661

0.948

0.651

0.725

1.614

2.394

1.222

1.908

0.981

1.244

1.072

2.085

1.567

1.709

1.132

1.213

0.555

0.478

1.273

1.453

2.372

3.253

1.788

3.309

1.462

3.021

1.530

3.652

0.693

0.555

1.448

2.825

1.814

4.877

1.837

3.042

2.722

4.923

2.262

4.441

2.008

4.131

2.057

4.268

4.583

7.716

3.663

6.784

50% T2

20% T3

30% T3

40% T3

50% T3

20% T4

30% T4

40% T4

50% T4

20% T5

30% T5

40% T5

50% T5

3.410

7.462

2.996

5.174

3.718

7.497

4.319

8.370

3.317

4.892

2.061

5.956

3.508

7.480

2.482

3.236

3.683

4.884

3.405

6.069

2.834

6.017

4.320

5.510

3.759

6.712

4.736

8.472

7.344

9.044

8.260

9.177

7.649

9.732

3.360

7.088

3.061

6.363

3.548

9.004

3.471

7.277

4.363

7.497

4.560

8.014

6.801

10.864

5.525

8.868

4.815

10.747

8.967

8.467

13.715

9.053

7.504

8.595

6.487

13.079

4.690

11.412

5.858

12.029

4.953

11.008

6.546

12.282

6.780

10.970

8.913

11.058

7.580

10.456

7.301

11.852

6.599

8.846

7.585

10.638

7.338

12.190

3.785

6.919

2.684

5.557

3.307

5.657

4.272

6.898

7.751

9.318

3.323

7.485

4.131

7.596

5.713

10.160

10.062

8.705

5.679

12.173

6.093

11.420

7.931

11.122

7.174

10.558

Data Pengujian Bending komposit serat rami Tabel data hasil pengujian bending komposit serat rami pada alkali 2 jam tebal 1mm Jenis

No Spesimen

Komposit

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

Volume

B/T1-20/1

2.16

25.4

31.89

202.5015

55.55596708

2048.610409

5040.3498

20%

B/T1-20/2

2.456

25.4

35.42

224.917

56.74080381

1840.134364

4923.5699

B/T1-20/3

2.512

25.4

33.52

212.852

55.61486707

1763.411557

4555.5864

Volume

B/T1-30/1

4.024

25.4

33.53

212.9155

44.49664096

767.1031041

2844.6936

30%

B/T1-30/2

3.668

25.4

42.98

272.923

39.02802803

635.6103478

4000.3408

B/T1-30/3

2.945

25.4

31.51

200.0885

32.58107063

699.7571

3652.7758

Volume

B/T1-40/1

5.898

25.4

36.35

230.8225

20.61436673

163.4005735

2104.067

40%

B/T1-40/2

3.267

25.4

30.92

196.342

17.96923781

262.8537556

3231.099

B/T1-40/3

4.351

25.4

29.85

189.5475

16.16448967

173.6845796

2342.1525

Volume

B/T1-50/1

1.309

25.4

95.37

605.5995

73.7389425

3188.011214

24873.222

50%

B/T1-50/2

1.458

25.4

90.53

574.8655

69.50847522

2628.825805

21198.001

B/T1-50/3

1.422

25.4

97.36

618.236

79.65419056

3170.090161

23374.422

Tabel data hasil pengujian bending komposit serat rami pada alkali 2 jam tebal 2mm Jenis

No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T2-20/1

1.408

30

136.21

1021.575

111.6383903

5663.473534

54416.282

B/T2-20/2

2.203

30

115.02

862.65

92.05282113

2984.657971

29368.475

B/T2-20/3

1.945

30

127.48

956.1

99.28134127

3561.236609

36867.609

B/T2-30/1

1.601

30

95.02

712.65

42.94452033

1436.976454

33384.603

B/T2-30/2

2.663

30

100.22

751.65

41.74702685

825.0889746

21169.264

B/T2-30/3

1.418

30

42.19

316.425

18.69976755

706.4691549

16736.16

B/T2-40/1

1.104

30

92.44

693.3

43.82917915

2165.473278

47099.185

B/T2-40/2

1.177

30

64.33

482.475

29.10951199

1349.015771

30743.946

B/T2-40/3

0.803

30

58.17

436.275

28.72592593

1987.403205

40747.976

B/T2-50/1

1.253

30

228.18

1711.35

69.31489095

2476.976723

102435.16

B/T2-50/2

2.515

30

205.07

1538.025

61.77784138

1067.989305

45865.557

B/T2-50/3

2.061

30

302.28

2267.1

92.18383093

2033.078182

82500


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T3-20/1

2.284

50

103.94

1299.25

55.91734519

3238.386266

118510.11

B/T3-20/2

4.057

50

116.27

1453.375

56.58384811

1816.043519

74633.093

B/T3-20/3

1.589

50

67.42

842.75

41.94233706

3491.458894

110492.71

B/T3-30/1

2.997

50

140.44

1755.5

42.04763143

1313.661709

122031.75

B/T3-30/2

2.021

50

148.98

1862.25

45.43606176

2178.485484

191968.7

B/T3-30/3

1.621

50

86.68

1083.5

31.49892436

1927.756502

139253.03

B/T3-40/1

2.391

50

373.12

4664

176.9332114

8685.407299

406385.06

B/T3-40/2

2.396

50

346.69

4333.625

140.6906907

6612.498434

376810.74

B/T3-40/3

1.991

50

298.23

3727.875

114.2544453

6462.326264

390075.65

B/T3-50/1

3.318

50

204.37

2554.625

57.56090691

1606.303075

160401.91

B/T3-50/2

3.804

50

168.34

2104.25

54.01745604

1408.747268

115243.27

B/T3-50/3

1.371

50

49.73

621.625

13.40411998

885.5881125

94460.4


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T4-20/1

6.888

65

163.21

2652.1625

59.13317899

1373.918196

135566.52

B/T4-20/2

6.897

65

163.72

2660.45

68.24309628

1639.400375

135812.69

B/T4-20/3

7.279

65

188.65

3065.5625

75.83333333

1746.685035

148280.46

B/T4-30/1

6.424

65

222.3

3612.375

77.25820997

1801.842035

197985.22

B/T4-30/2

7.386

65

150.87

2451.6375

52.26851983

1083.299467

116867.14

B/T4-30/3

6.645

65

177.56

2885.35

61.9531668

1396.838287

152879.4

B/T4-40/1

25.6

65

114.29

1857.2125

29.38254474

151.0675277

25542.717

B/T4-40/2

15.276

65

138.43

2249.4875

31.33818412

265.0593562

51846.495

B/T4-40/3

16.03

65

109.69

1782.4625

26.40340474

208.9820045

39150.052

B/T4-50/1

3.912

65

216.27

3514.3875

59.77709379

2089.316262

316297.87

B/T4-50/2

5.56

65

459.11

7460.5375

128.893856

3109.378448

472433.62

B/T4-50/3

5.02

65

470.19

7640.5875

146.7435966

4076.050225

535881.18


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T5-20/1

12.038

80

242.78

4855.6

71.36390359

1171.006276

215123.22

B/T5-20/2

5.406

80

120.54

2410.8

37.4607162

1356.226594

237839.44

B/T5-20/3

8.947

80

258

5160

67.68439201

1453.941173

307589.14

B/T5-30/1

11.38

80

152.95

3059

51.62052418

921.6150717

143362.62

B/T5-30/2

14.523

80

210.32

4206.4

67.35520648

916.1145868

154473.13

B/T5-30/3

11.19

80

205.37

4107.4

71.53023129

1298.760175

195765.27

B/T5-40/1

4.915

80

252.177

5043.54

66.40589268

2382.080566

547281.38

B/T5-40/2

3.194

80

198.111

3962.22

55.13293135

3287.886892

661610.52

B/T5-40/3

5.514

80

285.393

5707.86

80.92429112

2722.532174

552084.15

B/T5-50/1

3.415

80

353.189

7063.78

65.59440982

2906.134616

1103177

B/T5-50/2

4.715

80

295.63

5912.6

58.38643845

1886.952513

668798.87

B/T5-50/3

5.171

80

289.74

5794.8

57.18025971

1734.568266

597671.63


No Spesimen

Komposit

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

Volume

B/T1-20/1

1.922

25.4

36.24

230.124

63.13415638

2616.335371

6437.1661

20%

B/T1-20/2

2.557

25.4

38.27

243.0145

61.30633997

1909.664503

5109.6087

B/T1-20/3

2.29

25.4

38.67

245.5545

64.15951401

2231.557068

5764.9906

Volume

B/T1-30/1

2.37

25.4

31.42

199.517

41.69652428

1220.494969

4526.0333

30%

B/T1-30/2

2.301

25.4

31.62

200.787

28.71256971

745.4167059

4691.4291

B/T1-30/3

2.028

25.4

28.35

180.0225

29.31365764

914.2591641

4772.49

Volume

B/T1-40/1

3.013

25.4

39.06

248.031

22.15122873

343.7059392

4425.8126

40%

B/T1-40/2

3.004

25.4

68.6

435.61

39.86706707

634.2318141

7796.2203

B/T1-40/3

2.18

25.4

77.13

489.7755

41.76774166

895.7211877

12078.882

Volume

B/T1-50/1

6.988

25.4

87.11

553.1485

67.35240936

545.4598915

4255.7394

50%

B/T1-50/2

2.591

25.4

74.03

470.0905

56.83985883

1209.670666

9754.393

B/T1-50/3

2.701

25.4

52.86

335.661

43.24692392

906.1356559

6681.3233


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T2-20/1

1.848

30

59.69

447.675

48.92221949

1890.933035

18168.628

B/T2-20/2

3.448

30

68.35

512.625

54.70188075

1133.201043

11150.486

B/T2-20/3

3.249

30

101.95

764.625

79.39859383

1704.966691

17650.623

B/T2-30/1

3.748

30

80.83

606.225

36.53131528

522.154415

12130.97

B/T2-30/2

2.365

30

100.98

757.35

42.06360777

936.0989824

24017.442

B/T2-30/3

1.902

30

74.95

562.125

33.21989993

935.6664018

22165.812

B/T2-40/1

1.421

30

222.85

1671.375

105.6613217

4055.83731

88214.726

B/T2-40/2

1.512

30

186.09

1395.675

84.20626591

3037.74408

69229.911

B/T2-40/3

2.157

30

341.92

2564.4

168.8493827

4348.87402

89165.508

B/T2-50/1

1.859

30

304.98

2287.35

92.64464651

2231.451186

92281.469

B/T2-50/2

2.072

30

321.72

2412.9

96.9189405

2033.719584

87339.527

B/T2-50/3

2.225

30

355.54

2666.55

108.4260925

2215.037641

89883.708


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T3-20/1

4.806

50

146.74

1834.25

78.9427673

2172.73512

79512.155

B/T3-20/2

2.074

50

129.85

1623.125

63.19267805

3967.315954

163042.93

B/T3-20/3

0.893

50

50.95

636.875

31.69626332

4694.991516

148580.39

B/T3-30/1

0.903

50

86.91

1086.375

26.02078929

2698.121253

250640.23

B/T3-30/2

1.375

50

85.42

1067.75

26.05147265

1835.90364

161780.3

B/T3-30/3

1.533

50

138.04

1725.5

50.16280016

3246.228487

234493.91

B/T3-40/1

1.901

50

87.58

1094.75

41.53036732

2564.153739

119975.23

B/T3-40/2

3.489

50

172.66

2158.25

70.06736466

2261.52737

128872.29

B/T3-40/3

1.251

50

69.1

863.75

26.47279674

2383.030219

143843.26

B/T3-50/1

0.777

50

186.51

2331.375

52.53062949

6259.906274

625100.55

B/T3-50/2

1.854

50

264.48

3306

84.86715441

4541.186924

371494.07

B/T3-50/3

1.482

50

236.11

2951.375

63.64059456

3889.707564

414891.9


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T4-20/1

3.772

65

137.26

2230.475

49.73114484

2109.98593

208195.41

B/T4-20/2

2.188

65

95.82

1557.075

39.9404684

3024.491504

250557.66

B/T4-20/3

4.607

65

135.74

2205.775

54.56462585

1985.725175

168573.17

B/T4-30/1

3.598

65

213.36

3467.1

58.9727689

2241.086369

339274.08

B/T4-30/2

5.242

65

270.81

4400.6625

76.02915452

1945.356963

295574.19

B/T4-30/3

3.665

65

217.39

3532.5875

67.84616954

2581.281918

339362.94

B/T4-40/1

3.366

65

290.53

4721.1125

74.69166789

2920.651418

493827.99

B/T4-40/2

4.4

65

324.33

5270.3625

73.42276425

2156.040999

421728.82

B/T4-40/3

2.082

65

227

3688.75

54.64101446

3329.81809

623797.98

B/T4-50/1

3.327

65

222.3

3612.375

77.25820997

3479.120298

382283.45

B/T4-50/2

2.678

65

311.87

5067.8875

108.0465519

6176.15192

666287.8

B/T4-50/3

2.152

65

226.63

3682.7375

79.07437594

5505.174773

602523.46


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T5-20/1

4.921

80

102.43

2048.6

30.10875955

1208.577382

222025.33

B/T5-20/2

4.929

80

107.22

2144.4

33.32120451

1323.104344

232030.84

B/T5-20/3

9.253

80

170.22

3404.4

44.65595817

927.5398784

196226.09

B/T5-30/1

7.774

80

186.52

3730.4

62.95037705

1645.217118

255923.16

B/T5-30/2

5.365

80

251.82

5036.4

80.64562617

2969.24515

500667.29

B/T5-30/3

7.899

80

191.89

3837.8

66.83515646

1719.104493

259124.78

B/T5-40/1

2.87

80

306.15

6123

56.85830693

2997.447833

1137839.7

B/T5-40/2

3.851

80

324.51

6490.2

64.09019092

2535.99697

898841.86

B/T5-40/3

2.012

80

363.2

7264

71.67760864

5588.243764

1925513.6

B/T5-50/1

3.696

80

395.77

7915.4

104.2183076

4971.476635

1142193.4

B/T5-50/2

4.579

80

430.72

8614.4

119.8664193

4986.175784

1003351.5

B/T5-50/3

4.303

80

335.82

6716.4

95.22306238

4105.175016

832461.07


No Spesimen

Komposit

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

Volume

B/T1-20/1

5.579

25.4

26.87

170.6245

46.81056241

668.2976162

1644.2627

20%

B/T1-20/2

2.763

25.4

18.27

116.0145

29.26748971

843.6979693

2257.4471

B/T1-20/3

2.777

25.4

17.53

111.3155

29.08498269

834.2099091

2155.0927

Volume

B/T1-30/1

4.705

25.4

22.68

144.018

30.09793669

443.7737212

1645.6722

30%

B/T1-30/2

5.722

25.4

28.86

183.261

26.20634921

273.591341

1721.9018

B/T1-30/3

4.661

25.4

33.59

213.2965

34.73177285

471.3191769

2460.3156

Volume

B/T1-40/1

2.977

25.4

81.2

515.62

46.04914934

723.1545517

9311.8743

40%

B/T1-40/2

3.449

25.4

72.81

462.3435

42.31371943

586.3024007

7207.0536

B/T1-40/3

3.625

25.4

90.62

575.437

49.07289964

632.8809981

8534.4583

Volume

B/T1-50/1

2.164

25.4

70.73

449.1355

54.68758942

1430.191215

11158.513

50%

B/T1-50/2

1.71

25.4

38.32

243.332

29.4219018

948.7596425

7650.4909

B/T1-50/3

3.405

25.4

88.43

561.5305

72.348193

1202.466965

8866.3


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T2-20/1

4.281

30

110.79

830.925

90.80403246

1515.067115

14557.2

B/T2-20/2

4.237

30

92.56

694.2

74.07763105

1248.822129

12288.176

B/T2-20/3

2.244

30

118.08

885.6

91.96062737

2859.116632

29598.93

B/T2-30/1

1.052

30

240.42

1803.15

108.6584043

5533.256602

128551.57

B/T2-30/2

1.512

30

308.59

2314.425

128.5443526

4474.531905

114802.83

B/T2-30/3

1.246

30

280.01

2100.075

124.1081278

5335.994947

126409.01

B/T2-40/1

1.163

30

280.99

2107.425

133.2276185

6248.461742

135904.45

B/T2-40/2

1.563

30

189.77

1423.275

85.8714766

2996.736228

68295.345

B/T2-40/3

0.931

30

160.13

1200.975

79.07654321

4718.733931

96748.792

B/T2-50/1

1.875

30

393.88

2954.1

119.6500537

2857.314714

118164

B/T2-50/2

1.508

30

349.33

2619.975

105.2365208

3034.151794

130303.8

B/T2-50/3

0.92

30

264.59

1984.425

80.68982343

3986.651355

161773.78


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T3-20/1

2.918

50

126.89

1586.125

68.26392083

3094.454818

113242.87

B/T3-20/2

3.79

50

112.36

1404.5

54.68101121

1878.60774

77204.266

B/T3-20/3

2.244

50

113.75

1421.875

70.76447406

4171.292409

132007.11

B/T3-30/1

3.453

50

131.37

1642.125

39.33208018

1066.544756

99075.985

B/T3-30/2

3.065

50

126.46

1580.75

38.56789079

1219.314427

107446.3

B/T3-30/3

2.401

50

85.02

1062.75

30.89569161

1276.57175

92214.182

B/T3-40/1

2.844

50

411.47

5143.375

195.1187513

8052.483085

376770.91

B/T3-40/2

2.94

50

218.27

2728.375

88.57641425

3392.796403

193337.23

B/T3-40/3

2.53

50

224.7

2808.75

86.08447798

3831.698802

231287.06

B/T3-50/1

2.087

50

232.97

2912.125

65.61611041

2911.147953

290700.87

B/T3-50/2

1.788

50

191.9

2398.75

61.57746117

3416.596821

279496.41

B/T3-50/3

1.987

50

125.58

1569.75

33.84857001

1543.026503

164585.43


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T4-20/1

2.099

65

116.07

1886.1375

42.05372272

3206.378552

316378.07

B/T4-20/2

2.229

65

127.6

2073.5

53.18726537

3953.521691

327521.22

B/T4-20/3

4.263

65

175.63

2853.9875

70.5995671

2776.597178

235712.28

B/T4-30/1

3.311

65

108.46

1762.475

37.69422156

1705.6629

187417.12

B/T4-30/2

3.447

65

246.52

4005.95

85.40621402

3792.851316

409175.58

B/T4-30/3

4.819

65

219.54

3567.525

76.6005758

2381.511664

260648.7

B/T4-40/1

4.197

65

198.74

3229.525

51.09359473

1602.319694

270922.55

B/T4-40/2

4.188

65

206.2

3350.75

46.6801529

1440.139484

281696.09

B/T4-40/3

4.493

65

101.09

1642.7125

24.33330463

687.1430438

128727.29

B/T4-50/1

2.486

65

291.09

4730.2125

80.45736454

4425.200087

669923.16

B/T4-50/2

3.021

65

351.39

5710.0875

98.65176547

4379.96153

665483.83

B/T4-50/3

4.542

65

210.13

3414.6125

65.58036527

2013.310628

264691.36


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T5-20/1

10.054

80

91.67

1833.4

26.94591417

529.4061779

97256.15

B/T5-20/2

11.793

80

139.05

2781

43.21314575

717.1727923

125769.52

B/T5-20/3

5.71

80

83.34

1666.8

21.86363267

735.9053403

155684.76

B/T5-30/1

7.825

80

131.97

2639.4

44.53978801

1156.466933

179895.21

B/T5-30/2

11.947

80

182.6

3652

58.47784663

966.8686349

163031.17

B/T5-30/3

7.779

80

194.41

3888.2

67.71287075

1768.548097

266577.54

B/T5-40/1

7.748

80

204.74

4094.8

53.91428428

1226.839022

281865.43

B/T5-40/2

6.27

80

229.99

4599.8

64.00463822

1944.39548

391264.22

B/T5-40/3

8.619

80

224.45

4489

63.6436673

1369.806413

277773.91

B/T5-50/1

4.486

80

326.01

6520.2

60.54671449

2042.071381

775176.1

B/T5-50/2

6.104

80

442.98

8859.6

87.48782093

2184.055943

774102.23

B/T5-50/3

5.239

80

317.59

6351.8

62.67646401

1876.618095

646617.04


No Spesimen

Komposit

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

Volume

B/T1-20/1

2.729

25.4

18.88

119.888

32.89108368

959.9686741

2361.8829

20%

B/T1-20/2

5.525

25.4

17.74

112.649

28.41846018

409.6855767

1096.1784

B/T1-20/3

4.121

25.4

25.11

159.4485

41.66137566

805.217873

2080.1948

Volume

B/T1-30/1

6.338

25.4

54.87

348.4245

72.81630449

797.0047029

2955.5794

30%

B/T1-30/2

4.446

25.4

31.45

199.7075

28.55820106

383.7117216

2414.9665

B/T1-30/3

5.834

25.4

46.45

294.9575

48.02890291

520.7190943

2718.1862

Volume

B/T1-40/1

4.212

25.4

67.18

426.593

38.09829868

422.8687252

5445.1713

40%

B/T1-40/2

2.384

25.4

53.56

340.106

31.12653225

623.9620167

7669.98

B/T1-40/3

3.33

25.4

61.6

391.16

33.35787484

468.3197661

6315.335

Volume

B/T1-50/1

2.544

25.4

115.19

731.4565

89.06352927

1981.27781

15458.152

50%

B/T1-50/2

2.024

25.4

103.78

659.003

79.68175807

2170.850775

17505.039

B/T1-50/3

1.738

25.4

79.87

507.1745

65.34490756

2127.769394

15688.948


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T2-20/1

2.143

30

74.04

555.3

60.68355053

2022.650174

19434.204

B/T2-20/2

3.155

30

92.38

692.85

73.93357343

1673.841373

16470.285

B/T2-20/3

1.765

30

63.64

477.3

49.5627907

1959.132645

20281.87

B/T2-30/1

3.37

30

133.35

1000.125

60.26785714

958.0519893

22257.975

B/T2-30/2

1.698

30

102.9

771.75

42.86339116

1328.603037

34087.898

B/T2-30/3

0.815

30

38.2

286.5

16.93128989

1112.924401

26365.031

B/T2-40/1

1.742

30

192.18

1441.35

91.11955484

2853.132914

62055.827

B/T2-40/2

1.441

30

248.15

1861.125

112.2885963

4250.404251

96866.325

B/T2-40/3

1.334

30

131.2

984

64.79012346

2698.239358

55322.339

B/T2-50/1

1.924

30

235.52

1766.4

71.54458373

1665.014981

68856.549

B/T2-50/2

2.676

30

340.86

2556.45

102.6849125

1668.371231

71649.383

B/T2-50/3

1.972

30

225.25

1689.375

68.69262908

1583.3632

64251.078


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T3-20/1

1.837

50

38.56

482

20.74439899

1493.722439

54663.4

B/T3-20/2

1.731

50

7.21

90.125

3.508811773

263.9379162

10846.933

B/T3-20/3

1.774

50

92.92

1161.5

57.80602136

4310.202436

136403.14

B/T3-30/1

2.172

50

130.45

1630.625

39.05663287

1683.696177

156405.87

B/T3-30/2

1.194

50

50.61

632.625

15.43508582

1252.636391

110382.64

B/T3-30/3

3.524

50

120.78

1509.75

43.89063318

1235.592929

89254.044

B/T3-40/1

4.77

50

180.02

2250.25

85.36534283

2100.504494

98281.359

B/T3-40/2

2.242

50

131.05

1638.125

53.18155994

2671.23747

152219.47

B/T3-40/3

2.881

50

317.77

3972.125

121.7403853

4758.591754

287235.7

B/T3-50/1

1.91

50

286.38

3579.75

80.6590621

3910.173653

390461.39

B/T3-50/2

1.959

50

503.47

6293.375

161.5549994

8181.358694

669280.14

B/T3-50/3

1.341

50

237.87

2973.375

64.11498128

4330.735585

461933.72


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

B/T4-20/1

3.019

65

139.2

2262

50.43403294

2673.519593

263800.1

B/T4-20/2

4.228

65

111.1

1805.375

46.30960174

1814.774216

150341.17

B/T4-20/3

3.539

65

98.52

1600.95

39.60296846

1876.175022

159273.19

B/T4-30/1

6.815

65

170.63

2772.7375

59.30080237

1303.683937

143247.93

B/T4-30/2

7.163

65

200.15

3252.4375

69.3414479

1481.888698

159867.24

B/T4-30/3

4.157

65

137.99

2242.3375

48.1466405

1735.256059

189918.13

B/T4-40/1

4.483

65

257.33

4181.6125

66.15635872

1942.336786

328413.13

B/T4-40/2

3.609

65

203.27

3303.1375

46.01685101

1647.437603

322244.3

B/T4-40/3

5.257

65

226.83

3685.9875

54.60009388

1317.764769

246866.04

B/T4-50/1

5.16

65

319.87

5197.8875

88.4121653

2342.774883

354668.52

B/T4-50/2

4.643

65

340.38

5531.175

95.56073858

2760.558619

419434.53

B/T4-50/3

3.064

65

254.8

4140.5

79.52161553

3618.932796

475783.63


No Spesimen

Komposit Volume 20%

Volume 30%

Volume 40%

Volume 50%

Defleksi

Support span

Beban

Momen Bending

Teg Bending

Modulus elastisitas

Kekakuan

(mm)

(mm)

(N)

(Nmm)

(MPa)

(MPa)

(Nmm2)

2538.4

37.3074662

1954.223293

359006.45

1680

26.10502871

1172.113121

205551.73

B/T5-20/1

3.771

80

126.92

B/T5-20/2

4.359

80

84

B/T5-20/3

5.271

80

119.54

2390.8

31.36043496

1143.470071

241907.29

B/T5-30/1

6.094

80

161.59

3231.8

54.53651848

1818.253282

282839.95

B/T5-30/2

8.7

80

202.57

4051.4

64.87326064

1472.927728

248361.69

B/T5-30/3

8.717

80

186.63

3732.6

65.00310204

1515.083109

228372.15

B/T5-40/1

5.937

80

345.83

6916.6

91.06758295

2704.394911

621332.88

B/T5-40/2

5.277

80

306.08

6121.6

85.17996289

3074.617176

618694.97

B/T5-40/3

3.928

80

186.16

3723.2

52.78638941

2492.937308

505526.14

B/T5-50/1

4.256

80

180.42

3608.4

33.50767838

1191.193529

452180.45

B/T5-50/2

5.522

80

226.56

4531.2

44.74522712

1234.755582

437638.54

B/T5-50/3

5.776

80

282.5

5650

55.75144395

1514.079733

521698.98

LAMPIRAN IV

Tabel 4.1. Sifat mekanik dari beberapa jenis serat.( Dieter H. Mueller ) Cotton

Flax

Jute

Kenaf

E-Glass

Ramie

Sisal

Diameter

m

-

11–33

200

200

5–25

40–80

50– 200

Length

mm

10–60

10–40

1–5

2–6

-

60–260

1–5

Tensile strength

MPa

930

1800

400– 1050

GPa

26.5

53.0

69.0– 73.0

61.5

Density

g/cm

345– 1035 27.6– 45.0 1.43– 1.52

393– 773

Young’s modulus

330– 585 4.5– 12.6 1.5– 1.54

1.5

2.5

1.5–1.6

Maximum strain

%

7.0–8.0

2.7–3.2

1.6

2.5–3.0

3.6–3.8

511– 635 9.4– 15.8 1.16– 1.5 2.0– 2.5

Specific tensile strength

km

39.2

73.8

52.5

63.2

73.4

71.4

43.2

Specific stiffness

km

0.85

3.21

1.80

3.60

2.98

4.18

1.07

3

1.44– 1.50 1.5– 1.8

Tabel 4.2. Sifat mekanik dari beberapa jenis material polymers (Smith, W.F., Hashemi, J., 2006).

Density 3 (gr/cm )

Ultimate Tensile Strength (MPa)

Yield Strength (MPa)

Modulus of Elasticity (GPa)

% Elongation at break

Izod Impact Strength (J)

1.2

70

60

2.25

5

0.3

Phenolic Polybutylene terepthalate (PBT) Nylon 66

1.705

56

52

7

1.3

0.18

1.355

55

67

12

148

0.27

1.095

62

63

2.1

152

7

Polyester

1.65

58

70

3.5

2.4

0.22

Polyethylene

0.925

16

16

0.25

350

1.068

Polypropylene (PP)

1.07

50

28

2.25

427

0.16

Polyvinyl Chloride (PVC) Polymethyl Metharcrylate (PMMA)

1.305

47

38

3.1

62

5.3

1.17

62

69

2.9

15

0.16

Type

Epoxy

LAMPIRAN V UJI DENSITY SERAT Tabel 6.1. ASTM D 3800-79. ρs1

ASTM D 3800-79 = ( Mu x ρm ) / ( Mu – Mm ) …….....….[1]

ρs2 = (ρs1 – (ρa x wa)) / ws ………………… [2] ws = (Mu – ρa) / Mu …………………….......[3] ρs1 = massa jenis serat ρs2 = massa jenis serat (kadar air : 0%) ρa = massa jenis udara = 0.08298 gr/cm3 m = massa jenis air = 0.997 Mu = massa serat di udara Mm = massa serat dalam air ws = berat serat, gr wa = berat udara, gr

Tabel 6.2. Hasil Uji Density Serat Kenaf Dengan Kadar Air 10% (ASTM D 3800 - 79). Specimen serat

Massa di dalam air Ma (gr) 30.616 30.599 30.529 30.536

1 2 3 4 Jumlah total Massa jenis serat rata-rata

Massa di udara Mu (gr) 82.324 83.654 80.645 84.398

Massa jenis air ρu (gr/cm3) 0.997 0.997 0.997 0.997

Massa jenis serat ρs (gr/cm3) 1.587 1.572 1.592 1.562 6.314 1.578

Density (gr/cm2)

Density Serat Ramie 1,592457645

1,595 1,59 1,585 1,58 1,575 1,57 1,565 1,56 1,555 1,55 1,545

1,587317784 1,578503959 1,572010894 1,562229512

1

2

3

4

Rata-rata

Spesimen serat

Grafik 6.1. Hasil Uji Density Serat Ramie. Massa jenis Massa jenis/densitas suatu material merupakan. perbandingan antara berat dan volume dari material tersebut. Dalam menentukan massa jenis suatu benda yang bentuknya beraturan dapat mudah kita lakukan dengan menggunakan persamaan 2.1 ( Tipler, 1991). ρ =

mu g W ⇒ ρ = u …………………………………. (2.1) V V

ρ = massa jenis, gram/cm3

Wu = berat di udara, gram

mu = massa udara,gram

V = volume material, cm3

g = grafitasi,gram/second2 = 9,8 gr/sec2 Untuk benda dengan bentuk yang tidak beraturan, dimana kita kesulitan untuk menentukan volumenya. Kita dapat menghitung massa jenis dengan hukum Archimedes,bahwa berat benda di dalam air sama dengan berat di udara dikurangi dengan gaya ke atas yang diberikan oleh air. Gaya tekan ke atas merupakan volume dari benda tersebut.

Dengan massa jenis air murni ( ρ air) 0,997 gr/cm3 pada suhu 23ºC maka volume benda dapat kita hitung dengan persamaan 2.2 dan 2.3 sebagai berikut (Tipler,1991): Cara I : V =

ρ=

(Wu - Wa )

.........................................(2.2)

 air

W   air Wu ⇒= u Wu - Wa V

..................................(2.3)

Wa = berat di air, gram

Wu = berat di udara, gram

air = 0,997 gr/cm3

V = volume material, cm3

Cara II : Dengan Gelas Ukur  V = V1 – V2 V= volume benda, cm3 V1= volume benda + volume air V2= volume air/water



LAMPIRAN VI

Analisa perhitungan fraksi volume serat ramie Diketahui

:

Massa jenis serat (ρf)

= 1.578 gr/cm3

Massa jenis matrik Polyester (ρm)

= 1.65 gr/cm3

Specimen dengan Vf 20% tebal 1mm Volume composit (Vc)

= 18.75 cm3

Volume serat (Vf)

= 20% x Vc = 0.2 x 18.75 cm3 = 3.75 cm3

Berat serat (Wf)

= ρf x Vf = 1.578 gr/cm3 x 3.75 cm3 = 5.92 gr

Volume matrik (Vm)

= 80% x Vc = 0.8 x 18.75 cm3 = 15 cm3

Berat matrik (Wm)

= ρm x Vm =1.65 gr/cm3 x 15 cm3 = 24.75 gr

Berat composit (Wc)

= Wf + Wm = 5.92 gr + 24.75 gr = 30.42 gr

Checking fraksi volume (Vf) Vf 

Wf /  f W f /  f  Wm /  m

x100%

𝑉𝑓 =

5.92 1.578 × 100% (5.92 1.578) + (24,75 1.65)

𝑉𝑓 =

3.75158 × 100% 18.75158

𝑉𝑓 = 0.2 × 100% 𝑉𝑓 = 20%

Tabel perhitungan fraksi volume komposit serat ramie Perhitungan

Fraksi Volume Serat Ramie 3

Volume composit Vc (cm ) Volume serat Vf (cm3) Volume matrik Vm (cm3) Berat serat Wf (gr) Berat matrik Wm (gr) Berat composit Wc (gr)

1mm 18.75 3.75 15 5.92 24,75 30,42

2mm 37.50 7.5 30 11.835 39 50,84

20% 3mm 56.25 11.25 45 17.7525 58.5 76,25

4mm 75 15 60 23.67 78 101,67

Perhitungan

5mm 93.75 18.75 75 29.5875 97.5 127,09

1mm 18.75 5.625 13.125 8.87625 17.0625 25,936

2mm 37.50 11.25 26.25 17.7525 34.125 51,878

4mm 75 22.5 52.5 35.505 68.25 103,755

5mm 93.75 28.125 65.625 44.38125 85.3125 129,69

Fraksi Volume Serat Ramie 40%

Volume composit Vc (cm3) Volume serat Vf (cm3) Volume matrik Vm (cm3) Berat serat Wf (gr) Berat matrik Wm (gr) Berat composit Wc (gr)

30% 3mm 56.25 16.875 39.375 26.62875 51.1875 77,82

1mm 18.75 7.5 11.25 11.835 14.625 26,46

2mm 37.50 15 22.5 23.67 29.25 52,92

3mm 56.25 22.5 33.75 35.505 43.875 79,38

50% 4mm 75 30 45 47.34 58.5 105,84

5mm 93.75 37.5 56.25 59.175 73.125 132,3

1mm 18.75 9.375 9.375 14.7938 12.1875 26,98

2mm 37.50 18.75 18.75 29.588 24.375 53,963

3mm 56.25 28.125 28.125 44.3813 36.5625 80,94

4mm 75 37.5 37.5 59.175 48.75 107,93

5mm 93.75 46.875 46.875 73.9688 60.9375 134,91

LAMPIRAN VII Konversi Satuan

LAMPIRAN VIII Gambar Spesimen

Gambar hasil cetakan komposit serat Ramie dengan matrik polyester untuk pengujian bending dan impact

Gambar specimen uji bending komposit serat ramie sebelum pengujian.

Gambar specimen uji impact komposit serat ramie sebelum pengujian.

Gambar specimen uji bending komposit serat ramie setelah pengujian.

Gambar specimen uji impact komposit serat ramie setelah pengujian.

Gambar specimen uji tarik komposit serat ramie sebelum pengujian.

Gambar ramie jenis pujon

Gambar mesin pengolahan ramie

Mesin pemisah serat ramie dengan batangnya Proses Dekortikasi: Proses pemisahan serat dari batang tanaman, hasilnya serat kasar disebut “China Grass “.

Mesin pemisah ramie

Mesin pembersih ramie Proses Degumisasi: Proses pembersihan serat dari getah pectin, legnin wales dan lain-lain, hasilnya serat degum disebut “ Degummed Fiber “.

Mesin pelembut serat ramie

Proses Softening: Proses pelepasan dan proses penghalusan baik secara kimiawi maupun mekanis agar serat rami tersebut dapat diproses untuk dijadikan seperti kapas.

Mesin pemotong serat ramie dan membukanya Proses Cutting dan Opening: Proses mekanisisasi untuk memotong serat dan membukanya agar serat tersebut menjadi serat individual untuk serat panjang disebut “Top Rami” dan untuk serat pendek disebut “Staple Fiber “.

Beberapa benang hasil pengolahan serat ramie Serat ramie yang telah diproses sampai menyerupai serat kapas sudah dapat dipintal menjadi benang untuk ditenun menjadi tekstil dari ramie peringkat No.2 setelah sutera, (cotton nomor 7).

JURUSAN TEKNIK MESIN FAKULTAS TEKNIK UNIVERSITAS MUHAMMADIYAH SURAKARTA

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