Improvements in or relating to methods for the manufacture of bags and sachets

摘要

724,918. Packaging; making bags. CELLOPHANE INVESTMENT CO., Ltd. Jan. 23, 1953 [Feb. 15, 1952], No. 2026/53. Classes 94 (1) and 94 (2). Flat bags with rip-cords are made by feeding continuously a strip of bag material, securing a continuous length of rip-cord material to the strip at a position spaced from its longitudinal centre line, folding the strip about its longitudinal centre line to enclose the length of rip-cord, heat-sealing the folded strip to form transverse seams at intervals, cutting through the centre lines of the seams to form bags each having marginal seams and a ripcord extending therethrough, and providing cuts in the material of each bag extending partly through one or each seam on each side of one or each end of the rip-cord so that'the latter may be bent up and grasped. The cuts may be formed prior to, simultaneously with, or after the separation of the bags from the strip. In a modification, the folded strip is replaced by two superimposed strips heatsealed together along one longitudinal margin. As shown in Fig. 2, incisions 5, 51 are made in each transverse seam 4 on either side of the length of rip-cord 2 so that either end 7 or 71 of the rip-cord in a completed bag 6 may be bent up and grasped. Alternatively, the incisions may be made in alternate seams or non-centrally in each seam so that only one end of the rip-cord may be bent up. In a modification, Figs. 3, 4 and 5, the strip of bag material is formed with pairs of holes 8 at equal distances from the fold line so that when the strip is folded and heat-sealed the holes are superimposed and are positioned centrally of the seams, the ends of the rip-cord in a completed bag being thus left exposed. Alternate pairs of holes may be omitted-so that only one end of the rip-cord is left exposed, or the holes may be formed on one side only of the fold line and the heat-sealing tool so designed that it does not apply pressure over the areas of the holes, whereby the ends of the rip-cord in a completed bag will be left free but only one side thereof will be exposed. Specification 703,756 is referred to.