| 摘要 |
An acoustical insulator 10 is made by depositing thermoplastic particulate 30 on a first surface 32 of a base layer 14. The particulate is heated such that it at least partially melts and penetrates the first surface of the base layer 14, thereby increasing density and airflow resistance of the base layer proximate the first surface 32, such that the base layer has an areal mass of 0.1 to 1.0kg/sq. m and an airflow resistance of 300 to 5000 Nscu.m proximate the first surface. The base layer may be a thermoplastic foam or a fibrous layer comprising natural and/or synthetic fibres. The particulate may be low density or high density polyethylene, polypropylene or polyethylene terephthalate and may be in the form of beads, pellets, flakes, granules, spheres, powder and/or fibres. |
