| 摘要 |
1277350 Laminates SWISS ALUMINIUM Ltd 7 Sept 1970 [9 Sept 1969] 42811/70 Heading B5N A method of producing a laminate of a middle layer 5 of a synthetic resin which is in a plastic state during lamination and two covering layers 4 of harder material, e.g. aluminium, an aluminium alloy, or glass reinforced plastics comprises pressing the layers together between upper and lower rolls 2 and 3 with roll gaps less than the thickness of the initial assembly of layers, the upper rolls being staggered relative to the lower rolls. The middle layer is preferably a polyolefine, e.g. polyethylene or polyvinylchloride; alternatively the middle layer may comprise a material which is initially thermosetting and is set by heat applied during the laminating process. When the middle layer is a polyolefine and the covering layers are of aluminium or an aluminium alloy, films of fusible adhesive, e.g of a copolymer of ethylene with acrylic acid, may be used to bond the layers. In the apparatus described with reference to the examples, the guide rollers 1 and the first four upper and lower rolls are heated, the last three upper and lower rolls being cooled. |
