SOUND ABSORBING MATERIAL

PURPOSE:To prevent deterioration of sound absorbing characteristic, and form the sound absorbing material incombustible and washable by interposing thin incombustible film, which does not transmit oil and water, between a felt type metal fiber layer and a wire gauze type surface protecting material, and pressing them for integral formation. CONSTITUTION:A metal fiber layer 1 is made of felt type metal narrow fiber having the excellent corrosion resistance such as Al and stainless steel or the like. The surface protecting material 2 is made of the incombustible material such as expanded metal and wire gauze of the material as same as the layer 1. The incombustible film 3 is thin film of the material which does not transmit oil and water such as Al foil or the like. The layer 1, the film 3, and the protecting material 2 in this order are pressed integrally to form the sound absorbing material 4. Since countless number of fine irregularity is generated in the film 3 and the film 3 is thin, the film 3 transmits the sound, which entered from the surface, to the layer 1 without reflection, and the energy is absorbed by the layer 1. Penetration of the oil into the layer 1 is thereby eliminated to prevent deterioration of the sound absorbing characteristic, and the incombustible and washable sound absorbing material is formed.