EXPERIMENTAL STUDY OF SOUND ABSORPTION PROPERTIES OF REINFORCEDPOLYSTER BY SOME NATURAL MATERIALS

Abstract

Sound absorption in living, traveling and working environment constitutes one of the major requirements for human comfort today. Sound insulation requirements in automobiles, in manufacturing environments, and in equipments, generating higher sound pressure, strives the need to develop more efficient and economical ways of producing absorption materials. Traditionally, economics of recent research has enforced the research to focus on waste materials. The aim of this study is to use waste materials (particles of egg shell, palm leaf, jute, wood dust, chicken feather) for producing reinforced and polyester resien composite structures with 17% weight fraction. Two natural material composite plate shapes (flat and corrugated) with the same area is manufactured, where the echoic chamber is built and insulated with cork and sponge for different inside wall shape (flat, concave and pyramids) . The study concluded that the jute woven and saw dust composite exhibited a greater ability to absorb normal incidence sound waves than the composites with chicken feather, particles of egg shell, and palm leaf fiber for different shape cork and sponge insider insulator. The analysis of sound transmission loss revealed that the particles of egg shell and saw dust still obeyed the mass law of transmission loss. The composite surface layer of particles of egg shell and saw dust possessed a higher fabric density and therefore showed a better sound insulation than the composites with jute woven, chicken feathers, and palm leaf.