| 摘要 |
<p>790,666. Laminated materials. IMPERIAL CHEMICAL INDUSTRIES, Ltd. Feb. 10, 1956 [Nov. 25, 1955], No. 33807/55. Class 140. Fluted or quilted material is made by forming and locating the flutes or quilted seams in the cover material by exerting a vacuum upon it, thus drawing it into conformity with the recesses formed in one of two platens of a device for welding plastic material and welding the backing material to the cover through a thermoplastic wadding. High-frequency dielectric heating may be used and a suitable apparatus is shown, wherein 1 is the upper electrode and the lower electrode comprises bars 3 which are spaced by non- conducting members 5, holes 6 in these members permitting the exertion of vacuum on the cover sheet. Continuous materials may be made by using a suitably ribbed roller as one electrode. The cover and the backing material may be an unsupported thermoplastic sheet or a base material of loose construction, e.g. a woven, knitted or felted material of natural or synthetic fibres, e.g. hessian or canvas or a paper sheet, said base material being coated on one or both sides with thermoplastic material such as vinyl polymers or copolymers which may contain plasticisers, pigments, &c. The wadding may be of cellulose acetate mat or blown polyurethane. Specification 790,228 is referred to.</p> |
