| 摘要 |
1,141,732. Coating by extrusion; laminated tubular films. NATIONAL DISTILLERS & CHEMICAL CORP. 21 Feb., 1967 [21 Feb., 1966], No. 8272/67. Headings B5A and B5B. A process for making a coated tubular film comprises extruding a thermoplastic tube 12 from a die 11, collapsing the tube between rollers 13, printing on the outer surface of the tube in a press 16-21, reinflating the tube after passage through rolls 23 and then extruding a transparent thermoplastic coating from an extrusion head 24 on to the outer surface of the tube 12 to encapsulate the printing thereon. The tube is then cooled by an air ring 26 and rolls 29 and collapsed by plates 27, 28 prior to being stored or formed into bags. The initial tube 12 may be laminated, and the outer surface thereof may be treated at a station 14 prior to the printing stage.
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