SOUND ABSORBING MATERIAL, MANUFACTURE THEREOF AND SOUND ABSORBING BODY

摘要

PURPOSE:To eliminate the development of the deterioration of sound absorbing qualities with time and keep the satisfactory sound absorbing qualities over a long period of time by a constitution wherein laminate consists of aluminum expanded metal and thin ethylene fluoride-based film and/or thin polyvinylidene- based film. CONSTITUTION:The sound absorbing material 10 concerned is produced by fixing thin film 14 consisting of thin ethylene fluoride-based film or thin polyvinylidene-based film pinched by aluminum expanded metal 12 in preferable embodiment under pressure with press rollers or the like. The expanded metal is metal network formed by lancing a large number of slits on metal sheet and stretching the sheet to the direction nearly normal to the slits so as to form open meshes as a whole. As the expanded metal, Al expanded metal made of Al or Al alloy is used. There is no limitation for the thickness of the Al sheet and normally the Al sheet having the thickness of 0.2-1mm is used. In order to obtain favorable sound absorbing qualities, the preferable thickness of the thin film 14 is about 4-25mum.