Development of a novel porous laminated composite material for high sound absorption

A novel porous laminated composite material (PLCM), made of polymer, metal, and polymer fibers with low melting point, is developed. Manufactured by the premix, lamination, preheating, acid molded techniques, the proposed PLCM exhibits very high sound absorption coefficient in the frequency range of 500 to 2000 Hz with a relatively thin and light structure. Using a porous rigid body, a mathematical model, characterized by five macroscopic parameters-fibrous diameter, fibrous density, cross section of fiber, porosity, and frequency-is derived to predict the sound absorption coefficient of the PLCM. This presentation may be useful for developing a new PLCM with predictable sound characteristics. Computer simulations are performed for predicting the absorption coefficients of the novel PLCM, and experiments are conducted for examining the sound absorption coefficients of the developed PLCM.