| 摘要 |
<p>A soundproofing material comprises a fibrous mass of an open-celled foam comprising short fibres less than 20 mm. long embedded in an open-celled foam of a viscoelastic resin, the fibres comprising 20-40 wt.% and the resin 60-80 wt.% of the total compsn. The material is partic. suitable for preventing sound propagation through metal sheets. Compared to prior art prods. it is mechanically stronger and is effective in attenuating emitted noises in a large range of frequencies. The resin is pref. an acrylic acid or natural or synthetic rubber. The fibres are of plant, animal, mineral or synthetic origin, and are partic., cotton, coco, glass, rock, silica, polyamide, polyester, or polyolefin.</p> |
