GB641568A - - Google Patents

Abstract

641,568. Compound sheet materials. IMPERIAL CHEMICAL INDUSTRIES, Ltd. Dec. 3, 1947, No..31892. [Class 140] A solidified or extruded molten film of a polythylene composition having a viscosity of more than 700 poises at a temperature of 190‹ C. is brought into contact with a coated surface of a sheet material bearing either a solidified or a molten coating of a polyethylene composition having a viscosity at 190‹ C. of less than 700 poises, and bonded thereto by the application of heat and pressure. The material may be paper, wood veneer and woven or knitted fabric sheet formed from fibres of cellulose, cellulose derivatives, synthetic resins, asbestos, and glass, wire gauze, regenerated cellulose, metal foil, tin plate. The pressureapplying surface may be embossed or engraved to produce an embossed pattern on the compound material ; it may be treated with the sodium salt of sulphated sperm oil alcohols, silicone grease, or polytetrafluoroethylene, or a layer of regenerated cellulose or metal foil is interposed between it and the film, to prevent them sticking together. Transparent windows may be produced in the compound material by cutting away window areas from the sheet before it is bonded to the film. The compound material may be employed in the manufacture of tank-linings, bottle cap seals, leathercloth, food-packages, kegs, lamp-shades, liquid containers, book-covers, and glass substitute. As shown, sheet material which may be a printed fabric 1 is coated with polythene 2 by means of a doctor knife 3 and roller 4 and is tensioned by rollers 5 as it passes around a warm roller 6 so that a molten film 7 of polythene issuing from an extrusion orifice 8 is bonded to the fabric.