| 摘要 |
A needled composite acoustical barrier is provided. The barrier has a non-woven first layer (13) of needleable textile first fibers (13a); the layer (13) has a thickness of between about 0.01 inch and 0.5 inch and a density of between about 1.0 and 10 lbs. per cubic foot. A non-woven, low density second layer (15) of textile second fibers (15a) is provided; the second layer (15) has a thickness of between about 0.2 inch and 5 inches and a density of between about 0.1 and 4.0 lbs. per cubic foot. A high-density intermediate acoustical barrier layer (14) is disposed between the first and second layers (13, 15); the intermediate barrier layer (14) has a thickness of between about 0.01 inch and 0.5 inch, a density of at least 50 lbs. per cubic foot, and the barrier layer has a substantially continuous film of high-density needleable polymeric material. A plurality of needled stitches (19), formed from the first fibers (13a), extend from the first layer (13), through the intermediate barrier layer (14) and at least into the second layer (15). |
