New Multilayered Composite for Sound Absorbing Applications

Lightweight structures made of composite materials are increasingly used in many industrial fields for high-technology applications due to their versatile property profile. Waste wood cause both health and environmental problems and this has forced governments to develop laws for recycling. Using fir sawdust in the domain of soundproofing materials is of major importance from technical, economic and ecological point of view. In this paper we determined the sound absorbing ability of each obtained multilayered composite plates by measuring the sound absorption coefficient depending on frequency, using the impedance tubes. Multilayered composite plates were made from layers of composite materials in combination with layers of other materials on the market (cork or felt). The composite materials were made from fir sawdust and a polyurethane foam.