method and device for the continuous production of bags, sacks or bags

摘要

1370910 Extruding strip fasteners; seaming non-metallic sheet material MINIGRIP EUROPE GmbH 22 Dec 1971 [26 Dec 1970] 59679/71 Headings B5A and B5K [Also in Divisions B8 and E2] Film having releasable fastening strips secured thereto for making reclosable bags is made by heating and continuously feeding a laminated film F to a point where a continuously extruded fastening strip C is applied to the film before the strip has cooled so that the strip and film are fused together. One of the laminations may be a gas or moisture barrier, e.g. aluminium foil, and the other may be of the same flexible thermoplastics material as the fastener strip. A roll of film 4 drawn by rollers 7 over tensioning roller 6 is fed to pressure rollers 13, 14. A weakened tear line may be produced by thinning or by perforating by cutter 12. An extruder head 16 mounted for universal adjustment feeds a fastener strip C to the rollers 13, 14 where it is joined to the sheet F. Roller 14 is adjustable to vary the joining pressure and roller 13 may be heated. Cooling air is supplied by an air conditioning unit 19 via ducts 20 to blowers 17, 18 positioned to cool the strip C and the adjacent region of the film F. The finished film is drawn off by rollers 22 over guide rollers G and 21. Two co-operating fastening strips 31, 34 and two reinforcing and tear grinding strips 32, 33 may be attached to the film, the film being folded over between the strips 32, 33 so that these strips overlay one another and the fastening strips engage each other.