| 摘要 |
PURPOSE:To increase sound absorbing properties in a high frequency area and a comparatively low frequency area by bonding a breathable decorative surface material on one surface of a mat-shaped material with a number voids and also bonding a thermoplastic resin film on the other surface under the specific condition. CONSTITUTION:Automobile ceiling materials are bonded together with inorganic fibers with thermoplastic resin as a bonding material, and a breathable decorative surface material is bonded on one surface of a mat-shaped material with a number of voids all over, while a thermoplastic resin film of 1-200mum thickness is bonded on the other surface. If the thickness of the thermoplastic resin film is in the range of 1-30mum, the bonding area rate of the thermoplastic resin film and the mat-shaped material should be in the range of 40-100%, while in the thickness of the thermoplastic resin film is in the range of more than 30mum to less than 200mum, and said bonding area rate should be more than 1% to less than 40%. An automobile ceiling material of good sound-absorbing properties is manufactured by said process in the high and low wound areas in the rage from 800Hz to 2000Hz frequency. |
