Experimental investigation of fabric-based micro perforated panel absorber

Abstract

The most popular sound absorbers are made of porous material. Although porous material provides decent sound absorption, their fibers may harm health and environment. Thus, micro perforated panels (MPP) are considered an alternative option to deal with the health and environment issues. However, manufacturing minute holes of the MPP in Indonesia is not easy. As an alternative to MPP, this research uses microstructure of available materials on the market. The inherent microstructure potentials of fabric as MPP material will be investigated. Two kinds of woven fabric, namely Alabama and Lisburn, also one kind of denim fabric are employed. Absorption coefficient of the fabrics is measured using impedance tube with various air cavities. Measurement results show that all of the three fabrics are potential to be used as sound absorbers, as the absorption coefficient of the fabrics are greater than 0.5 at various frequency bands. For further investigation, the geometrical properties of the fabrics are measured using Scanning Electron Microscope. From the measured microstructures, woven fabrics are predicted to be more feasible for further development as the microstructures are more predictable compared to the denim fabric. For woven fabric themselves, Alabama shows greater performance than Lisburn in terms of absorption coefficient. It is predicted that the fibrous holes for Alabama made the resistive part become more apparent rather than Lisburn that has clearer holes, thus increasing its potential as sound absorber.