Improvements in the production of laminated products

Abstract

Abstract 1,237,490. Extrusion laminating. CADILLAC PRODUCTS Inc. 12 Nov., 1969 [18 Nov., 1968], No. 55458/69. Heading B5N. A laminate is formed from at least an extruded plastics layer 30, a layer 40 and a further plastics layer 44, which is dissimilar to layer 40 and whose surface has been treated by oxidation, by flame or electronically to improve adhesion, by simultaneously contacting the layers between oppositely-rotating rolls 14, 16, bonding being achieved by the heat of the extrudate 30. A substrate layer 22 may be included. The nip roller 16 should have a resilient surface, and the chill roller 14 and back-up roller 18 should be fluid-cooled. More than one roller assembly may be necessary for complete bonding. The arrangement shown may be reversed, with layer 30 being extruded into contact with the chill roller 14 and layers 40, 44 being fed over the nip roller 16. Layer 30 should be extruded at 200- 700‹ F., preferably 590-620‹ F., and the chill roller 14 should be below 120‹ F. The substrate 22 may be of paper, cloth, metal foil, polyethylene terephthalate, regenerated cellulose, single-faced corrugated paperboard, plastics foil, or expanded plastics, or may be a supported film of cellulose acetate, polyethylene terephthalate, vinyl chloride-vinyl acetate copolymer or polyvinyl butyral. The extrudate 30 is preferably polyethylene, but may be another polyolefin, vinyl polymer or hot-melt adhesive, and may be expanded. The layer 40 is preferably metal, but may be paper, cloth, rubber, regenerated cellulose or polyethylene terephthalate. The plastics layer 44 is preferably a polyolefin film, e.g. polyethylene, but may be polyethylene terephthalate, cellulose ester, regenerated cellulose or a vinyl polymer, and may be foamed, or may be a supported film or a laminate. Further layers may be present, in which case the other surface of layer 44 should be treated to improve adhesion. In a modification a laminate is formed from a temperature-sensitive substrate, a plastics layer and a hot extrudate whose temperature is below 590‹ F., with the substrate in contact with the nip roller 16 and the extrudate in contact with the chill roller 14; the surface of the plastics layer is treated as above to improve adhesion. The extrudate may be polyethylene, ethylenevinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polystyrene or an acrylate. The plastics layer may be surface-oxidized polyethylene and the substrate may be regenerated cellulose, vinyl polymer or polyethylene terephthalate.

Inventors

No inventors recorded.

Bibliographic Details