This paper highlights the sound absorption performance of microperforated panel (MPP) made from coconut fiber and polylactic acid (PLA) composite named as biocomposite microperforated panel (BMPP). Coconut fiber was used to produce BMPP specimen and PLA was used as matrix. Impedance tube method was employed to identify the sound absorption performance of BMPP specimen while a porosity tester was used to determine the porosity of BMPP specimen. Comparison on the sound absorption performance between BMPP and steel MPP will be discussed in this paper. It has been found that BMPP with different composition percentage of coconut fiber and PLA possessed different sound absorption performance mainly due to the existence of pores and tortuous structure within the specimen itself. Scanning electron microscope (SEM) scan was performed to further analyze the structure of BMPP specimen.

Additive manufacturing (AM) of Natural Fiber-Reinforced Composites through Fused Deposition Modeling is receiving much attention in recent years. AM is very appealing for complex shape structures that can be inconvenient to produce by other methods. In this study, the acoustic panel made from polylactic acid reinforced with wood fiber composite was 3D printed by varying its thickness and infill density. The sound absorption coefficient was measured using an impedance tube. The thin panel with back air gap was found to absorb sound at mid-frequency range resembling the Helmholtz resonator. The absorption performance for the thick panel can be controlled by controlling the infill density of the panel. Customizing the acoustic absorption is therefore possible for panels from biodegradable materials by AM.