Pengaruh Model Anyaman 3D Serat Cantula Terhadap Karakteristik Serapan Bunyi Komposit Unsaturated Polyester Resin (UPRs)-Cantula 3D

Abstract
The aim of this research is to investigate sound absorption coefficient characteristics of natural fiber composite, it is formed from cantula fiber woven as the reinforcement and UPRs resin as the matrix. The cantula woven fiber models are varied in four types AI, LAIS, LAIW, OI at 40 % fibre weight. The manufacture precede by plaiting the continous twisted cantula fiber and continue with making the sample that have 10 cm roundness longitudinal section. After that the acoustical characteristic spesimen are tested by impedance tube method with varies frequencies include 125 Hz, 160 Hz, 200 Hz, 250 Hz, 315 Hz, 400 Hz, 500 Hz, 630 Hz, 800 Hz, 1000 Hz, 1250 Hz, 1600 Hz, 2000Hz and then the surface roughness of spesimen are tested by contact-stylus profilometer.
The result of this research presents the varied woven models cause cantula 3D-UPRs skin composite have different surface roughness value and it influence to sound absorbing coefficient value of cantula 3D-UPRs skin composite. 3D-UPRs skin composite reinforced LAIW wovens cantula model form the best wovens model because this models has maximum absorbing coefficient in almost all frequency that is tested and it has highest roughness value (Ra) average (as big as 26.865 μm) too.
Key words : absorption coefficient, Impedance tube method, surface roughness, composites, woven model, cantula