Plastics bags having self-sealing spouts

Abstract

Abstract 1,061,973. Valve bags. B.X. PLASTICS Ltd. Jan. 13, 1964 [Feb. 1, 1963], No. 4141/63. Heading B8K. A plastics valve bag 1 includes a valve 4, the thickness of the material of which is graduated from e.g. 11-20 thou. at 8 to about 1 thou. at 7, the valve being such that it can be pulled out manually to form a spout. The valve is formed by pushing a plug into a heated thermoplastic sheet and withdrawing the plug when the stretched sheet has cooled. The end of the formed shape is then cut open to produce the valve. The shoulder 5 of the valve is welded to the bag along at least two discontinuous weld lines, thus allowing air to escape from the bag between said lines. A support ring is employed during the welding operation after which the bag is sealed at 6. Alternatively, a longer spout valve may be employed and it may be welded to the bag along the weld 6, the weld being such that the valve can still be pulled out manually to form a spout. The valve may be coloured to facilitate location. Preferably, materials for the bag are listed in the Specification.

Inventors

• 👤 William Ralph O'connell

Bibliographic Details