Performance of dry rubber foam as a sound absorbing material

Abstract

The present study aims to investigate the actual sound-absorbing capability of dry rubber foam. Two sound-absorbing foam materials were produced from dry synthetic rubbers known as ethylene-propylene-diene monomer (EPDM) and nitrile butadiene rubber (NBR). The acoustical efficiencies of dry rubber foams and commercially available acoustic foams; polyurethane and melamine were studied. The results showed a significant influence of the sound absorption properties of the different dry rubber foams and acoustic foams. EPDM reached a peak absorption coefficient of 0.94, while NBR peaked at 0.75, both occurring at frequencies below 1500 Hz. In contrast, acoustic foams reached their sound absorption peak at frequencies exceeding 2000 Hz. These properties were governed by the physical and microstructural properties of the foams. This study can be helpful and valuable for designing a dry rubber foam with optimum non-acoustical properties to achieve the desired acoustical properties in various service applications.