Acoustic properties of natural fiber reinforced composite micro-perforated panel designed using 3D printing

The present study investigated the acoustic performance of biodegradable MPP absorbers made of natural fiber-reinforced composites (NFRC) using 3D printing. The novelty of this current research lies in the recent development of a methodology that aids industry professionals in optimizing the production of MPP (Micro Perforated Panel) at a competitive cost. This is achieved by addressing and eliminating issues commonly faced in traditional manufacturing processes, such as manual preparation and pressing. The fused deposition modeling (FDM) technique was used to fabricate test samples utilizing the PLA/corkwood composite. Using an impedance tube device with two micro-phones, the acoustic absorption coefficients of MPPs with different perfora-tion diameters, thicknesses, and perforation rates were measured. Maa's analytical model was used to predict the acoustic absorption performance. Moreover, considering the average sound absorption and total cost of fabricating the samples, central composite design (CCD)-response surface method (RSM) was employed to optimize these samples. In the end, the parallel arrangement of MPP double layer and the combination of MPP with kenaf porous material were tested to improve the sound absorption performance. The results showed that the average sound absorption coefficient of the NFRC-MPP sound absorber is 25% more than that of conventional MPP sound absorbers.