| 摘要 |
<p>The invention is concerned with a process for the manufacture of multilayer moisture-impermeable strips having at lesast two very thin continuous flexible plastic layers bonded together by an adhesive medium constituted by a layer of asphalt, the thickness of which is a large multiple of the thickness of the plastic layers and is adjustable at will. The process of the invention comprises the steps of continuously feeding at least two very thin strips of polyethylene in spaced facing relation to each other to define a space between their facing surface; continously supplying an asphalt mixture containing 65-70% of asphalt, 25-30% of slate shale and 5-10% of latex or a latex-type elastomer, in a hot molten condition, into such space; continuously bonding the very thin strips to the asphalt mixture by supplying pressure to the outer surfaces of the strips to subject the strips and the asphalt mixture to compression to form a three-layer multi-layer moisture-impermeable strip; simultaneously with such pressure application, and in the zone of pressure application, continuously cooling the very thin strips by conducting heat away from the outer surfaces thereof while the strips are subjected to compression; and thereafter further cooling the multi-layer strip. The invention enables one to obtain a thick strip (about 4 mm thick) having two very thin layers (0.02 to 0.09 mm thick) of an extremely flexible material (polyethylene) and a thick layer of an adequate asphalt mixture placed between them, and to obtain a perfect adhesion in such a type of strip, in which the proofing base is the polyethylene layers, whereas the thick asphalt layer acts both as a protective and as adhesive.</p> |
