Mechanical Characterization and Acoustic Insulation of Wool-Polyester-Glass Hybrid Composite Material

Abstract

Composite materials have better physical, mechanical, electrical, acoustical, and thermal properties than conventional materials. Noise pollution becomes a major problem amongst which profoundly influence the air proportion and human wellbeing broadly. There are mainly two ways to control the sound (1) to control the sound source and (2) to use highly effective sound absorption and sound insulation materials. This paper represents exhaustive experimentation on composite material developed from wool fiber and polyester resin to determine its mechanical and acoustic properties to develop a novel material with excellent sound insulation properties for infrastructure and automotive industry applications. The mechanical properties of composite material such as tensile strength, flexural strength, hardness, density, and water absorption are evaluated using relevant ASTM standards. The sound absorption coefficient of composite material developed from wool fiber and polyester resin is also evaluated. Six different samples are prepared for acoustical testing containing three samples of 8 mm thickness and remaining of 10 mm thickness with a single layer, double layer, and triple layer of wool felt. It has been observed that tensile strength, flexural strength, and density of material decreases with the increase of wool fiber percentage. It can be concluded from the obtained results that the material with 10 mm thickness and triple layer of wool felt is having the sound absorption coefficient of 0.85 which is almost equivalent to natural wood material of 60 mm thick in the frequency range 50–2000 Hz. Also, the sound absorption coefficient improves by addition of wool fiber layers and increasing the thickness of the material.