GB1200787A - Improvements in or relating to packaging - Google Patents

Abstract

1,200,787. Wrapping articles. SCHWEIZERISCHE INDUSTRIE-GES. 13 Sept., 1967 [14 Sept., 1966], No. 41697/67. Heading B8C. A tube of substantially rectangular crosssection and comprising a single sheet of packaging material folded around an article is closed by a longitudinal seam and two transverse seams and has its two opposing narrow longtudinal sides bent inwardly. The corners of the tube are strengthened by further marginal folds. Near the centre line of one of the faces 3 of the tube in the preferred arrangement, the opposed edges 4 of the sheet 1 are folded outwardly, welded together and later folded back against the face 3. The edges 5 at the ends of the tube are similarly welded together to form fin-seals, and the narrow sides 2 are bent inwardly to form creases 16. In the manufacture, a length of packaging material such as plastics-covered aluminium foil is folded about successive articles to produce a filled tube of substantially rectangular cross-section, Fig. 5. The tube 10 is then advanced in the direction 13 about two guide plates 12, the distance between which decreases in the forward direction to allow for the inward folding of the sides 2. Beyond the plates 12, the tube 10 moves between two stationary jaws 14 having edges 15 which produce the fold lines 16. The edges 17 of the tube pass between the appropriate upper or lower surface of jaws 14 and pressure rollers 18 to form margins 19. The elements 14, 18 may be heated to cause welding of the margins 19. The tube is advanced by driven heated rollers (not shown), which grip and simultaneously seal the margins 4, and the resulting seam is then folded flat against the tube. The subsequent transverse sealing and severing of the tube between articles is not described. In modifications, the seam 4 may be situated at a corner 17 of the tube and may be adhesively sealed without heat. Also, the sides 2 of the tube may be merely concave instead of having sharp folds 16.