Sound Absorption Performance of Coir Fiber/Polylactic Acid Composite Microperforated Panel

Abstract

Microperforated panel (MPP) is considered a unique and promising sound absorber, as its sound absorption performance depends on parameters such as perforation ratio, perforation diameter, and air gap thickness. In this study, the MPP was fabricated through conventional mixing, granulating, and hot compression methods. The MPP was made from coir fiber/polylactic acid (PLA) composite, outside the norm of using metallic materials to produce MPP. The panel's sound absorption performance was measured using an impedance measurement tube and then compared with pure PLA MPP, which was taken as a benchmark for this study for a fair comparison. The MPP produced in this study demonstrated outstanding sound absorption performance due to its porous and tortuous structure. The porous and tortuous structure coincided with the perforated hole mechanism in absorbing sound; thus, the performance was better than pure PLA MPP, which did not possess an apparent porous and tortuous structure. This study proved that natural fiber composite has considerable potential to be used for MPP production, as it is a sustainable and natural resource that brings less harm to the environment compared to the common usage of metallic materials.