GB1095828A - Container with vent means - Google Patents

Abstract

1,095,828. Vented bags; vacuum packaging. UNION CARBIDE CANADA Ltd. July 20, 1966, No. 32491/66. Headings B8C and B8K. A vent 12 is provided in a flexible, fluidimpervious bag 10, in order that the interior of the bag may be evacuated, and a sealed area 13 prevents the solid contents 14 of the bag from reaching the vent. As shown the bag 10 comprises a thermoplastic tube heat-sealed transversely at 19, 20. Alternatively two sheets may be sealed together around their margins, the vent 12 and sealed area 13 being provided similarly to the embodiment shown. The sealed area 13 may be replaced by a series of spaced sealed areas (18), Fig. 6 (not shown), with the same effect. After filling and closing of the bag, it is evacuated through the vent (12) by the application of external pressure to the bag walls, and/or by the direct withdrawal of air through the vent (12) by a vacuum device, and the vent is then sealed, for example by an adhesive strip (24). Alternatively a peripheral seal (23), Fig. 4 (not shown), may be formed around the vent (12) to close it. If the material being packaged is of a heated granular form the bag may be evacuated by simultaneously cooling the material and withdrawing air through the vent. The vent may pass through one or both walls of the bag, which may alternatively take a block-ended, gussetted, rectangular or cylindrical form. The material of the bag may alternatively be paper, metal foil &c., coated with a heatsealable thermoplastic.