Experimental Study of Sound Absorption Coefficient Characteristics of Oil Palm Frond Reinforced Composite

Abstract

This study aims to investigate the capability of sound absorption coefficient (SAC) of oil palm frond (OPF) composite. Also, to characterize the fiber surface without treatment and with alkali treatment. Two parameters were formulated to characterize the SAC ability of the OPF composite: chemical treatment and density of composite. The composite was manufactured from a waste OPF as a reinforcement and urea-formaldehyde (UF) resin as a matrix. The fibers were blended with UF 10% (weight fraction) and formed by hot-pressing under the pressure of 9 tons at 140°C for 5mn. The SAC was measured by the impedance tube respected with ASTM 1050 (the transfer function method) within the frequency of 125-6400 Hz. Morphological analysis is investigated by scanning electron microscopy (SEM) on untreated and alkali-treated OPF fiber. The measurement data were obtained and compared with different densities and treatments. It reveals that the SAC of OPF composite was proportion to density and alkali-treated. The SAC worsens as the composite becomes dense due to the greater density. The treated fibers have more roughness and friction area than untreated fiber; thereby, the incidence of sound energy rapidly dissipates to thermal energy, causing improved SAC performance