| 摘要 |
1468256 Seaming non-metallic sheet material; extruding and rolling ALTSTADTER VERPACKUNG VERTRIEBS GmbH 11 June 1974 [15 June 1973] 25857/74 Headings B5K and B5A [Also in Division B8] Tubular packaging material for liquids is produced from a web 1 of liquid impermeable sheet material, e.g. polyethylene-coated paper or cardboard, by feeding the web 1 to an extruder 20, bending the web 1 into tubular shape with its longitudinal edges 5, 6 adjacent, applying, from the extruder 20, molten plastics material 7 between the edges 5, 6 and over the marginal areas of the web adjacent these edges, and cooling the plastics material to form a buttwelded seam. Preferably, the plastics material 7 is polyethylene. In a form-fill-seal packaging machine, the web 1 is bent into tubular shape as it passes between rollers 10, 11 at the outlet 23 of the extruder 20. Liquid polyethylene from the extruder 20 is formed into the desired profile by circumferential grooves 26 in the rollers 10, 11 which are cooled by the circulation of a cooling liquid 17 therethrough. Liquid to be packaged is supplied through a filler tube 19. |
