Acoustical Absorptive Properties of Cotton, Polylactic Acid Batts and Fabrics
W.O Ogunbowale, P. Banks-lee, K.A Bello, S.Maiwada, E.G.Kolawole

Abstract
This study investigated the absorptive properties of nonwoven cotton and Polylactic acid batts and fabrics. Fibrous nonwoven materials convert sound that passes through them to heat energy. The nonwoven samples used in this study were made from 100 percent cotton and 100 percent polylactic acid fibers, which are all natural fibers that are degradable and are environmentally friendly. The method used for measuring the acoustical properties of the batts and fabrics used in this research is the impedance tube method, whereby; sound absorption coefficient is determined at each frequency in accordance with the ASTM 1050 - 08 standards. The results of this study shows that physical elements such as; fibre type, fibre size, layering order, fibre cross section, material thickness, density, airflow resistance and porosity are important factors in determining the absorption behavior of nonwovens materials. The results of the acoustical data show that eight (8) layers cotton batts absorbs better than cotton fabric and Polylactic acid batts and fabric. It is recommended that these fibres (cotton and PLA) which are environmentally friendly and cost effective be adopted as good alternatives to petroleum based fibres which are currently in use since they are effective sound insulator.

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