Sound Absorption Characterisation of Layered Arrangements of Pineapple Leaf Fiber-Epoxy Composite prepared by a Simple Mixing – Hot Pressing Process

Abstract

As with other natural fiber-based composites, pineapple leaf fiber-epoxy composites could be potentially used as sound absorber materials. Sound absorption coefficient of a material depends on several factors, such as thickness and sound frequency. Layered arrangement is usually used to increase thickness. In this research, sound absorption characteristic of one-, two- and three-layer arrangement of the Pineapple leaf fiber-epoxy composite containing 11 and 17% (w/w) of epoxy concentration have been studied. The composites were prepared by a simple mixing followed by hot pressing process, and the sound absorption coefficient was measured according to ISO 10534-2 by using an impedance tube. At low frequency range (<1 kHz) the sound absorption coefficient increases as the layer number increases. At frequency range >1 kHz, the sound absorption coefficient variates at above 0.6. In this frequency range, the sound absorption coefficient of Pineapple Leaf fiber-epoxy composite is influenced by epoxy concentration. The composite containing 11% of epoxy concentration gives higher sound absorption coefficient compared to that of 17%. One-layer composite is better sound absorbing materials at frequency >3 kHz, as it gives higher sound absorption coefficient compared to other arrangements.