Acoustic Performance and Modeling of Sustainable SCB/PVA Composite Materials

Abstract

The rising need to use sustainable and environmentally friendly materials in place of
synthetic acoustic materials has resulted in the rising popularity of natural fiber
composites. Sugarcane bagasse (SCB), an agricultural by-product that contains a high
level of fibrous material, is also a potential solution in the sound absorption applications
because of its porous structure and biodegradability. The purpose of the research is to
compare the acoustic behavior of SCB-based composite panels bonded with polyvinyl
acetate (PVA), and to compare experimentally obtained sound absorption coefficients
(SAC) and those obtained using mathematical models. Three levels of SCB content (40%,
50% and 60%) and three thicknesses (10 mm, 20 mm and 30 mm) were used to make
composite panels. The panels were described in terms of airflow resistivity, porosity, and
tortuosity and the SAC values were determined using an impedance tube in accordance
with ASTM E1050 and ISO 10534-2. The Miki, Delany-Bazley (DB) and JohnsonChampoux-Allard (JCA) models were also used to predict the SAC. Findings have shown
that adding more SCB content and panel thickness has a significant effect on SAC
especially at the low and mid frequency bands. Panels with 60% SCB and 30 mm
thickness recorded the highest SAC values of more than 0.9, which validated their
outstanding sound-absorbing performance. The JCA model was the closest to the
experimental data among the models analyzed with the Miki and DB models underpredicted. This paper confirms SCB/PVA composites as a potential solution to sustainable
acoustic panels usage.