Effect of biomass ash mixture composite on sound absorption

Abstract Given that noise is an unwanted variable in human comfort whether in industrial or in commercial application, biomass combustion in recent days has gained increased interest within the heat and power industries; moreover, the application of biomass ash is used widely in many sectors. However, the effectiveness of sound absorption by various biomass ash mixture remains unexplored. This research aims at evaluating the effect of biomass ash mixture composite, in particular, coconut coir and spent coffee ground, toward sound absorption. It is formulated on the ratios of 1:1, 1:2, 1:3, 2:1 and 3:1 of epoxy resin to biomass ash via standing wave tube according to ASTM E1050-98. The results obtained from the research’s experiments indicated that, at 5 kHz, the average sound absorption coefficients for epoxy specimen infused with coconut coir ash, coffee ash, and mixture of both ashes, are 0.1, 0.098, and 0.097, respectively, and that the unmingled epoxy specimen has an average sound absorption coefficient of less than 0.09. Therefore, the research concluded that coconut coir ash composite provides better sound absorption property, compared to coffee ash, mixture of both ashes, and purely epoxy composites.