Composite Manufacturing of Coir Fiber-Reinforced Polyester as a Motorcycle Helmet Material

Abstract

Berdasarkan standar SNI 1811-2007 helm di Indonesia terbuat dari bahan polimer ABS (Acrylonitrile Butadiene Styrene) yang harganya relatif mahal. Oleh karena itu, dibutuhkan alternatif pengganti dengan pemanfaatan limbah serat alam sebagai bahan pembuatan komposit. Tujuan penelitian ini yaitu menganalisis pengaruh komposisi material, ketahanan impak, dan kekuatan bending material helm dari serat sabut kelapa dan resin poliester dengan perbandingan 20%:80%, 40%:60% dan 60%:40%. Ukuran panjang serat yang digunakan adalah 50 mm dengan perlakuan kimia pada serat menggunakan larutan NaOH 5% selama 2 jam. Komposit dibuat dengan metode compression molding. Penelitian ini menggunakan metode pengujian berupa uji impak ASTM D6110, uji tekuk ASTM D790-03, uji mikrostruktur, dan uji SEM. Didapatkan hasil data dengan nilai tenaga patah optimum sebesar 55,542 J dan nilai kekuatan impak optimum sebesar 0,408 J/mm² pada spesimen B. Hasil uji bending didapatkan nilai kekuatan tekuk optimum sebesar 52,785 MPa dan nilai modulus elastisitas optimum sebesar 13,064 GPa pada spesimen A. Standar uji kekuatan impak menurut SNI 1811-2007 adalah 29000 J/mm, sedangkan nilai kekuatan impak spesimen ini sebesar 0,408 J/mm² sehingga masih belum mencukupi untuk dijadikan bahan alternatif helm.

Based on the SNI 1811-2007 standard, helmets in Indonesia are made of ABS (Acrylonitrile Butadiene Styrene) polymer material which is relatively expensive. Therefore, an alternative is needed by utilizing natural fiber waste reinforced as a composite material. The purpose of the study was to analyze the effect of material composition, impact resistance, and bending strength of helmet material from coconut fiber and polyester resin with a ratio of 20%: 80%, 40%: 60%, and 60%: 40%. The fiber length used is 50 mm, with chemical treatment on the fiber using 5% NaOH solution for 2 hours. Composites were made by the compression molding method. In this study, testing was used in the form of impact test ASTM D6110, bending test ASTM D790-03, microstructure test, and SEM test. The data was obtained with the optimum fracture strength value of 55.542 J and the optimum impact strength value of 0.408 J/mm² on specimen B. In the bending test, the data was obtained with the optimum bending strength value of 52.785 MPa and the optimum elastic modulus value of 13,064 GPa at specimen A. The impact strength test standard according to SNI 1811-2007 is 29000 J/mm, while the impact strength value of this specimen is 0.408 J/mm². Thus, it is still not sufficient to be used as an alternative helmet material.