| 摘要 |
1490126 Corrugating sheet material I C I AUSTRALIA Ltd 23 April 1975 [10 May 1974] 16811/75 Heading D1S A hot sheet 1 of thermoplastic material is corrugated by passage between cold tips of projections 3 set in and extending from two series of separately movable combs 4 (or 8, 9), the projections 3 of one series of combs 4 interdigitating with those of the other series and the combs 4 of each series forming a block 10, the projections 3 being non-linear or zig-zag in the plane of each block 10 and being such that a straight line cannot be drawn in the plane of the block to separate the projections 3 one from another. The sheet 1 is a thermoplastic film either extruded directly from a dye 2 or fed into the machine via a radiant reheat line. The combs 4 are conveyed by endless belts or chains 5 and their interdigitation is effected by cams 6. After cooling, individual sheets are cut from the sheet 1, e.g. by a retractable knife cutting the sheet 1 while it is still held by the combs. Preferably, the combs 4 of one series are not identical to those of the other series. As shown in Figs. 2 and 3, a comb 8 of one series and a comb 9 of the other series each comprises a strong steel strip bent in zig zag or sinuous form and affixed edgewise to a wooden base. Thin sheet metal fins or fillets are provided so that each pair of fins forms a counter ridge running from the crest of the steel strip to the wooden base. In each comb 8, the fillets are triangular and, in each comb 9, the fillets are triangular with an extension beyond the hypotenuse. Specified thermoplastic materials for the sheet 1 are polyvinyl chloride, vinyl chloride and vinyl acetate polyvinylidene chloride polymers, copolymers of ethylene and vinyl alcohol, low density polyethylene, high density polyethylene, polypropylene, high impact polystyrene, poly (4-methylpentene-1), polyesters, e.g. polyethylene terephthalate, polyamides, e.g. nylon 66. 610, 6 and 11, soda or borosilicate glass or thermoplastic synthetic rubber. |
