| 摘要 |
1396251 Coiled web; apparatus for coiling a web WINDMOLLER & HOLSCHER 18 July 1973 [29 Aug 1972] 34209/73 Heading B8C In a coiled web 1 of flattened paper, or plastics, bags or sacks connected end-to-end along transverse lines 4 of weakness provided in the web a relatively weak adhesive 9 is applied, on the side of the web facing the interior of the coil to the trailing end, as viewed in the direction of coiling, of at least the outermost bag, or sack, in the coil. As shown in Figs. 1 and 2, each bag is formed by a weld seam 5 which is located respectively in advance of, or trailing, the corresponding transverse line of weakness 4, in the unwinding direction of the roll 1, so that, when a bag is torn off the end of the roll, the adhesive dabs 9 are disposed respectively adjacent the mouth, or base of the bag. Each bag may have side folds, or gussets; and the adhesive is preferably pressuresensitive. Wider bags, e.g. waste disposal bags, can be folded about one, or more, longitudinal fold lines so as not to cover the adhesive dabs 9, the preferred method being shown in Fig. 3, whereby marginal portions 10, 11 are folded inwards to define a gap S between them and to expose, and slightly overlap, the adhesive 15. In an apparatus for forming a roll of web shown in Fig. 3, a flattened tubular web is unwound by feed rolls 25, 26 from a reel 21 and passes successively through perforating rolls 23, 23<SP>1</SP> and a welding station 28 which includes a plurality of welding jaws 29, 29<SP>1</SP> which are mounted to co-operate on the adjacent vertical runs of a pair of conveyer arrangements, not shown, the speed of the outer return runs of which can be adjusted according to the speed of the web and the desired interval between adjacent weld seams. An adhesive roller 39 and tray 38 is located next to the welding station to transfer adhesive to pads 37 carried by the jaws 29. The web is pulled from the welding station 28 by the rolls 33, 34 of a feeding device 32 which has a fine speed control drive 35 to adjust the tension of the web, and which protects the web from tension applied further downstream by the feeding rolls 57 of a web-coiling machine 14. On leaving the feeding station 32 the web is passed over a trapezium-shaped oblique plate 42 on which the web marginal portions are folded downwardly as shown in Fig. 3. The web then passes over guide rolls 51, 52 leading to one, or other, of two alternately operable mandrels 61, 62, a web tensioning roll 59, being loaded by a weight 58. Each mandrel 61, 62 comprises a cluster of rods which can be projected through the front of the machine, and withdrawn again. |
