Search

This paper highlights the sound absorption performance of microperforated panel (MPP) made from coconut fiber and polylactic acid (PLA) composite named as biocomposite microperforated panel (BMPP). Coconut fiber was used to produce BMPP specimen and PLA was used as matrix. Impedance tube method was employed to identify the sound absorption performance of BMPP specimen while a porosity tester was used to determine the porosity of BMPP specimen. Comparison on the sound absorption performance between BMPP and steel MPP will be discussed in this paper. It has been found that BMPP with different composition percentage of coconut fiber and PLA possessed different sound absorption performance mainly due to the existence of pores and tortuous structure within the specimen itself. Scanning electron microscope (SEM) scan was performed to further analyze the structure of BMPP specimen. [ABSTRACT FROM AUTHOR]

Oil palm mesocarp fibre is seen as one potential of reinforcement in polymers due to its high strength, low cost, environmentally friendly nature and availability. Recently, it has attracted greater interest from academia and industries due to its potential for making a low-cost sound absorption panel. Therefore, this study is obliged to investigate the acoustic characteristics and the physical properties of oil palm mesocarp fibre (OPMF) as a porous material for sound absorbing panel. The measurements of the sound absorption coefficient are determined by using: (1) analytical model of Delany-Bazley, (2) analytical model of Johnson-Champoux-Allard, and (3) experiment of the impedance tube method. A commercial polyurethane (PU) was used as a composite binder during the intermixing process with the fibres. The manufacturing parameters are 10/90, 20/80, 30/70 and 40/60 by wt.% of PU/OPMF. The outcome shows that adding binder compacts the fibre by reducing the pore diameter and porosity, thus increasing the flow resistivity. Results also indicate that Johnson-Champoux-Allard model can justify the overall trend of absorption of the coefficient perfectly in contrast to the Delany-Bazley model. Overall, OPMF with 10 wt.% PU binder displayed greater absorption from low to mid-frequency range and the highest value of noise reduction coefficient of 0.66, while fibres with 20 wt.% PU produced the highest value of sound absorption coefficient of 0.99 at 1000 Hz. The results conclude that oil palm mesocarp displays a potential and brighter prospect to be implemented as a sound absorption panel as demonstrated in this study. [ABSTRACT FROM AUTHOR]