Mechanic and Acoustic Properties of the Sound-Absorbing Material Made from Natural Fiber and Polyester

A sound-absorbing composite material made of wood fiber and polyester fiber was produced using polyester foam technology and wood-based composite technology. This study investigated the physical and mechanical properties and the effects of the airflow resistivity of the materials and the depth of the cavities behind on sound-absorbing performance of the composite material. The results showed that the composite of best physical and mechanical properties and sound absorption was made with a 150 degrees C hot-pressing temperature, 10 min hot-press time, 3 : 1 the ratio of wood fiber to polyester fiber, foaming agent content of 8%, and the nominal density of 0.2 g/cm(3); the composite material yielded superior sound absorption property with the airflow resistivity of 1.98 x 10(5) Pa.s/m(2); the acoustic absorption peak moved to lower frequencies when length of the cavities was increased.