| 摘要 |
<p>1,237,396. Paperboard. NATIONAL GYPSUM CO. 14 June, 1968 [15 June, 1967], No. 16323/68. Heading D2B. An acoustic tile comprises two layers, both of mineral-wool fibres, and a substantially continuous film of water-based latex paint between the two layers. This tile may be made by first making a slurry of clay, starch, wax emulsion, boric acid, sodium ortho-phenylphenate, sodium pentachlorophenate, mineral wool and water, mixing, removing shot, felting on a cylinder machine and laying the mat on trays. Latex paint is then sprayed on to the surface of the mat. A second slurry of ethylene oxide polymer, boric acid, starch, clay, stucco, wax emulsion, mineral wool and water is heated to cook the starch, mixed, laid on top of the latex layer and screeded to produce a travertine appearance. The slabs are then baked.</p> |
