GB620214A - Improvements in bags - Google Patents

Abstract

620,214. Paper and like bags. ROYAL & CO., T. M. Jan. 9, 1947, No. 730. Convention date, April 1, 1946. [Class 94(ii)] A bag having bellows-folded side walls with self-opening or automatic type bottom, or a flat bag with a satchel'type bottom, made of three sheets 1, 2, 3, is formed with flap portions 24, 25, Fig. 5, to expose areas 27, 28 of sheet 2 which is of, or coated with heat-sealable material. When the portions 24, 25 are folded along the lines a, b pressure and heat are supplied to seal the bag bottom. A flap extension 5 of sheet 1, which, like 3, is of paper or other non- sealable material, may be also heat sealed or secured by adhesive. A recess 18, in the liner sheet 3, is cut to expose a portion 19 of the intermediate sheet 2 during the final sealing operation. The plies are seamed together at their outer ends by adhesive preferably of thermo-plastic material and a strip 20 may be applied to allow closure of the bag after filling. The three sheets are assembled with relative exposures of edges, before being folded into a tube 1, and then folded about the line 22 and opened out on the fold lines 23. The sheet 2 may be of material known by the Registered Trade Mark " Pliofilm " or "Cellophane," the latter being coated with heat-sealable adhesive.