Patent ID: 8312963
Filing Date: 2012-11-20
Classification: B32B,B60R,G10K

Abstract:
1. A sound absorbing material having a ventilation resistance in the range of between 0.400 and 20,000 kPa·s/m comprising a sound absorbing surface material having a ventilation resistance in the range of between 0.100 and 1.000 kPa·s/m and an air-permeable porous material sheet laminated onto said sound absorbing surface material, wherein said sound absorbing surface material comprises air-permeable stretchable paper having a ventilation resistance higher than at least 0.060 kPa·s/m and a unit weight in the range of between 10 and 50 g/m 2 , laminated onto one or both sides of a fiber sheet and interposed between the fiber sheet and the air-permeable porous material sheet, so that the ventilation resistance of said sound absorbing surface material, and thus said sound absorbing material, is adjusted by said stretchable paper.