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US 3,939,972 AGranted
Pouch made of coextruded polymers
AssigneeTower Products, Inc.
InventorRobert G. Mayworm
Life of this patent
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AssigneeTower Products, Inc.
InventorRobert G. Mayworm
Estimating the term…
A pouch is formed from a section of coextruded polymer tubing, which is pressed flat, folded over along a longitudial axis, and heat sealed along the sides, whereby the opposed walls of the pouch are each composed of two thicknesses of the coextruded material. The outermost laminate of the coextruded tubing that form the innermost and outermost surfaces of the pouch walls is composed of a polymer, such as low density polyethylene, which can be rapidly and reliably heat sealed in the formation of the pouch, with the outermost surface being suitable for printing. The inner laminate, which is encapsulated by the outer laminate, is composed of one of a group of polymers which have relatively poor heat sealing properties but otherwise provide toughness, puncture resistance, gas and vapor barrier properties or coloration to the pouch, such as polyamides, ionomers, pigmented polyolefins and medium and high density polyethylenes.
A pouch comprising a single tubular section of coextruded laminated film having free edges at opposite ends said tubular section comprising an inner laminate and an outer laminate surrounding the inner laminate said section being flattened and overfolded medially along a line perpendicular to said free edges and defining a closed end in said pouch and a pair of superimposed walls each having two layers of said film, and means securing said walls together adjacent facing edges, said outer laminate constituting the innermost and outermost surface of each of said walls, the outer laminate being a heat sealable polymer selected from the group consisting of low density ethylene homo- and copolymers, polyisobutylene modified polyethylene and mixtures thereof, said inner laminate being a polymer selected from the group consisting of ionomers, polyamides, pigmented polyethylene, medium and high density polyethylene.
A pouch comprising a single tubular section of laminated polymeric film, said tubular section consisting essentially of an outer laminate and an inner laminate, said section being flattened and overfolded medially and defining a closed end in said pouch and a pair of superimposed walls each having two layers of said film, and means securing said walls together adjacent facing edges thereof, said outer laminate constituting the innermost and outermost surface of each of said walls.
Dependencies are inferred from the claim text.