Investigation of Peanut Shell as Alternative Sound Absorbing Material

Abstract

Use of natural material for development of sound absorbers received considerable significance since in past few years. Natural materials are preferred due to their ease of availability, low environmental impact, distinctive internal structure and reusability. One such natural material Peanut shell is made up of natural cellulose fibers and has good internal pores which can be utilized for sound absorption application. In the current study samples of Peanut shell specimens were made of 100mm diameter having different material to binder weight ratios. The test specimens were made with thickness 10mm, 15mm, 20mm, 25mm, 30mm, 35mm and 40mm respectively. Normal incidence sound absorption coefficient for the specimens is measured using ASTM E1050-98 (Standard Test Method for Impedance and Absorption of Acoustical Materials Using a Tube, Two Microphones, and a Digital Frequency Analysis System) and values of the normal incidence sound absorption are compared with values obtained using Delany and Bazley Model. It was observed that Peanut shell test specimen with material to binder weight ratio 70:30 gives optimum average sound absorption for frequency range between 250Hz to 4500Hz. The current paper concludes that Peanut shell can prove to be good alternative natural material over existing conventional sound absorbing materials for application in field of sound absorption.