Patent GB-768382-A (GB)
Title: Improvements in or relating to household bags and methods of and machines for manufacturing such bags
IPC: B31B150/00
Filed: 1954-10-29
Abstract: 768,382. Making paper and like bags. WINDMÍLLER, A., and HÍLSCHER, F. [trading as WINDMÍLLER & HÍLSCHER]. Oct. 29, 1954 [Oct. 30, 1953; Dec. 21, 1953; May 18, 1954], No. 31398/54. Class 94(2). A rectangular-bottomed bag is provided with a filling opening on one of the longest sides of the bottom. In a machine for making the bag from a continuous tube which is cut into bag lengths, a bottom without the filling opening is first formed on one end of the bag length which is then turned through 180 degrees and the bottom with the filling opening formed on the other end. Fig. 1 shows a gussetted bag in which the bottom is provided with a.recess 10, 11, 12, 13, which forms the filling opening, and slits 14, 15 and 16, 17, which form a bottom flap. The bottom is folded in known manner, Fig. 3, the edges 12, 16<SP>1</SP>, and 11, 141, being arranged to overlap and being secured together by glue, and the flap 3, 15, 14, 16, 17, 4, is folded over and with the exception of the portion 14, 18, 19, 16, is glued to the bottom as shown in Fig. 4. After the bag has been filled, the portion 10, 2, 5, 13, is folded over (indicated by dot-dash lines 2, 10<SP>1</SP>, 131, 5,) beneath the free end of the bottom flap, which is then secured by adhesive. A dry-sealing adhesive may be used. The recess 10 ... 13 may be formed by making two slits 11, 10, and 12, 13, a tab remaining attached to act as an additional sealing member. A bag without gussets is provided in a similar way with a filling opening and may have an additional bottom cover sheet which is attached to the bottom but leaving a free portion which is secured by dry-sealing adhesive after the flap with the filling opening has been folded over. In the manufacture, Figs. 11 and 13 to 22, a web is drawn from a roll 6 through apparatus 3, 4, which removes windows 12 and a longitudinal stripe of glue 13 is applied at 10. The web is formed into a tube at 11 and provided with slits 16, 17, at 15. Cutter 20, 21, severs the tube into bag lengths the cut being made at the trailing edge of window 12. A nose 22 forms the leading ends of the tubes into a bottom square, glue being applied at 23, and the bottom flaps are creased and folded over by the devices 24, 25. A belt 29 conveys the tubes to a cylinder 31 where they are gripped and conveyed to 33 where a bottom cover sheet 34 is glued to the bag bottom. The bags are then conveyed by cylinder 31 to a point 35 where their direction of movement is reversed and they are conveyed by belts 38, 40, to a cylinder 43. At 44 slits 45, 46, are made by knives 51, 52, and a glue stripe 47 is applied for subsequently sealing the overlapping flaps 48, 49. The bottom is opened and the flaps 48, 49, successively turned down and glued together at 56, 57, 58, thus forming the filling opening 59. Glue is applied to the bottom at 60 and at 61 the bottom is creased along lines 62, 63, and 64, 65, the leading flap being folded over by rod 66 and pressed by roller 68. Finally a bottom cover sheet 73 is applied at station 71 glue being deposited only on the area 72, so that after the bag has been filled the flap with the filling opening may be folded over about the crease 64, 65, and covered. A similar machine is described which instead of the window 12 forms a thumbhole in which the tab remains attached, and when the web is severed the tab assists in closing the end of the bag opposite to that provided with the filling opening.