Acoustic performance of natural fibres of oil palm frond ( 30%) and acasia

• Main Author: Logan A / l Balloo
• Published: 2023
• Subjects: Acoustic performance; Natural fiber; Sound absorbers
• Institution: Universiti Tenaga Nasional

Noise is often viewed as unwanted or excess sound which can be harmful to the human health. In order to filter all the unwanted noise, sound absorbers are invented. Sound absorbers are usually made up of sound absorbing materials which retains the excess sound by converting the sound energy into heat energy and are released into the surrounding. However, most of the sound absorbers are made up of synthetic fibres which are proven to be hazardous to human health. This phenomenon influenced the motive to carry out this project which is the drive to fabricate sound absorbing materials which consists of natural fibres of Oil Palm Frond and Acacia Mangium. This project has investigate the density effect on the morphology and the sound absorbing properties of low density fibreboards in thickness of 16mm. The low density fibreboards are developed by implementing the fabrication process which includes several steps such as chipping, refining and many more. As for the microstructure and the acoustic properties, they are determined when all the samples undergo Scanning Electron Microscope (SEM) testing and Impedance Tube (BNK Tube) method respectively. From the results, it can be viewed that from 0 to 2500Hz, the Sound Absorption Coefficient (SAC) values in average increases as the density increases. From 2500Hz to 4500Hz, the SAC values in average are seen to be increasing as the density decreases. Since the densities are quite close to each other, the SAC values does not fluctuate vigorously when compared to each one and another. The SAC values of all the samples can also be seen to be reaching unity from 4500Hz to 6400Hz (0.95~0.99). In terms of morphology, it can be seen that when the density increases, the content of parenchyma increases which is one of the key components in retaining sound waves. The results shows and validates that the natural fibres of Oil Palm Frond and Acacia Mangium is a good mixture and can be used as an alternative material to be used in sound absorbers