Karakteristik Akustik Dan Mekanik Dari Green Composite Serat Sabut Kelapa (Cocos Nuciferal) Bioresin Getah Pinus (Pinus Merkusii) Dengan Variasi Waktu Perlakuan Alkali (Naoh) - Giannitra K, Dimas; Kencanawati, C.I.P.K; Putra Negara, D.N.K (Teknik Desain Mekanika; Vol 8 No 2 (2019): April 2019 : Teknik Desain Mekanika, 2019)
Abstrak Penelitian ini bertujuan untuk mengetahui pengaruh variasi waktu perlakuan alkali (NaOH) pada green composite serat sabut kelapa (Cocos nuciferal) bioresin getah pinus (Pinus merkusii) terhadap kemampuan meredam bunyi dan kekuatan impact. Green composite memiliki perbandingan fraksi volume 10% - 90%, diberi perlakuan alkali (NaOH) 5% dengan variasi waktu perendaman 1, 2, 3 dan 4 jam serta tanpa perlakuan alkali (NaOH). Noise absorption tet dilakukan menggunakan Tabung Impedansi Dua Microphone dengan standar ISO 10534-2 : 1998 dan ASTM E : 1050 : 1998. Uji impact dilakukan menggunakan alat uji Impact Charpy Test dengan standar ASTM D 256. Berdasarkan hasil dari pengujian, didapat bahwa perendaman alkali (NaOH) mempengaruhi kemampuan meredam bunyi maupun kekuatan impact dari green composite. Pada frekuensi 500 Hz, koefisien absorpsi bunyi tertinggi dimiliki oleh green composite dengan perendaman alkali (NaOH) 2 jam yaitu dengan nilai 0,95. Namun, green composite tanpa perlakuan alkali memiliki kekuatan impact terbesar yaitu 0,01152 J/mm2. Persentase perbedaan kekuatan impact (Is) secara berturut-turut adalah menurun sebanyak 26.057 %, kembali menurun sebanyak 18.65 %, mulai meningkat 18.724 % dan kembali meningkat sebanyak 11.822%. Kata Kunci: Green komposit, serat sabut kelapa, getah pinus, alkali, koefisien absorpsi bunyi, kekuatan impak. Abstract The purpose of this research is to identify the influence of alkaline onto green composite - consisting of coconut fibres (Cocos nuciferal) and pine resin with the variation of time to determine its noise absorption capacity and impact strength. The volume fraction of pine resin to coconut fibres was 90% to 10% respectively and was treated with an alkaline solution of 5% with each study conducted at 1, 2, 3, 4 hours and a control study with no treatment of alkaline. The Noise absorption test was done with a tube, two microphones following the ISO 10534-2:1998 and ASTM E:1050:1998. The Charpy Impact Test method was used in this study with the ASTM D256 standard. The results obtained from this study proves that treatment with alkaline influences the capacity of noise absorption and impact strength of the green composite. At a frequency of 500 Hz, the highest noise absorption coefficient was with a treatment of 2 hours with a value of 0.95, whereas, the control study with no treatment of alkaline had the highest impact strength at 0.01152 J/mm2. The difference in percentage of impact strength (Is) reduces consecutively by 26.057% then 18.65%, but takes a turn and starts increasing by 18.724% and 11.822% respectively. Keywords: Green composite, coconut fibres, pine resin, alkaline, noise absorption coefficient, impact strength