Investigation and analysis of sound-absorbing properties of waste tea leaf fiber as fillers in pineapple leaf/glass fiber-reinforced composites

Abstract

To control the noise pollution through sound absorption, the development of natural fiber-reinforced hybrid composites (NFRHCs) using waste tea leaf fibers (WTLFs) and pineapple leaf fibers as reinforcing materials with epoxy matrix will act as an initial step to address this issue. Also, a minimal additional reinforcement of glass fibers was added for achieving mechanical strength too. The fabricated samples underwent a sound absorption test for assessing their capability of absorbing unwanted noise. With the help of sound absorption coefficient (SAC) curves acquired from the impedance tube method, the effects of the weight fraction and mass densities of WTLF and the thicknesses of the fabricated composites on their sound absorption ability were investigated. From the investigation, it was found that the noise reduction coefficient of the developed NFRHCs was more than 0.7 at a broad frequency spectrum. The fractal dimensions were estimated using the MATLAB program by utilizing the box-counting dimension method to correlate the effects of porosity percentage with weight fractions and mass densities of WTLF and the thicknesses of the fabricated NFRHCs. Following that, a quantitative relationship between the fractal dimension and SACs of the developed NFRHCs was derived to offer a theoretical concept for the future design of similar sound-absorbing materials.