Patent GB-1241947-A (GB)
Title: Plastics containers and packages
Inventor: FORD ANDREW GEORGE
IPC: B65D81/20
Filed: 1967-08-01
Abstract: 1,241,947. Sealing plastics-film containers. IMPERIAL CHEMICAL INDUSTRIES Ltd. 8 July, 1968 [1 Aug., 1967 (3); 31 Aug., 1967; 29 Feb., 1968; 12 June, 1968], Nos. 35333/67, 39820/67, 28354/68, 28356/68, 27902/68 and 9848/68. Divided out of 1,241,948. Heading B8C. A plastics film container 14 for contents including a gas at super atmospheric pressure comprises at least one bunched neck having a thickened region 15 and a closure member 16 applied to the neck between the thickened region and the container body, the neck being sealed internally to retain the gas. The container end is arranged, in one embodiment, to be opened by the internal pressure when the member 16 is removed. The neck, which is heat sealed, may be arranged to peel apart or the adjacent material to rupture. The member 16 is a plastics coated wire, and may be coated with adhesive, e.g. a hot melt adhesive applied by heat or resistance heating through the wire, a tacky adhesive, or a pressure-sensitive adhesive. Alternatively a U-shaped metal clip could be used. A strengthening collar 19 of adhesive tape may be applied to the container end to form a spout by confining the rupture of the container. A double seal may be made across the container top, before bunching, excepting at the spout, where a single seal is made, or a single seal which is narrower at the spout, e.g. a wedge-shaped seal, may be made. The thickened region 15 of the neck may be formed by folding over the end of the flattened container and sealing it down with adhesives or heat and pressure, or by affixing material to the inside or outside of the neck, e.g. adhesive tape, or heat-sealable material, melted plastics, wax, or low molecular weight polymers coated on the surface or injected into the neck. Also the neck may be formed by heat sealing the end and crimping or embossing it; applying a hot knife face to the bunched end; or heat shrinking the neck at 16. An extra closure member (12), Fig. 10 (not shown), e.g. a metal clip, may be applied to the thickened neck 15. The container may have a longitudinal seam, preferably lapped, and a filling aperture (7), Fig. 4 (not shown), formed by a hot tool, hot air, or a flame. The container is made of oriented polyethylene terephthalate, when it may be opened by pricking it with the wire 11 after placing it in an upstanding cardboard tube. The container is rendered impermeable to water vapour, carbon dioxide, and oxygen by coating it with a vinylidene chloride polymer or copolymer, especially a copolymer containing acrylonitrile and a small proportion of other monomers, e.g. itaconic acid or methacrylic acid. Other than polyethylene terephthalate, the container may be of oriented or unoriented nylon, oriented polypropylene, polyvinyl chloride, or copolymers of vinylidene chloride with minor proportions of other monomers, e.g. vinyl chloride, acrylonitrile, or acrylic or methacrylic esters. A double-walled container may have one strong wall, of a material listed with polyethylene terephthalate above, and one wall of an impermeable material listed above. The outer wall may be a sleeve formed by winding a sheet or strip of plaltics film, paper around the container and sealing it by heat or adhesive, when the contents are chilled. The sleeve may extend to form a stand. When the contents are solid, solid carbon dioxide may be included. A label may be included between the walls of the container.