Abstract: Certain blends or mixtures of polyethylene and ionomer resins are blow extruded to make a film having excellent linear tear properties in the direction of extrusion, which property is not found in films of either of the resins alone.

Abstract: 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.

Abstract: A pouch made from thermoplastic film and particularly suited for sterilizing and storing medical items has an edge defined by a fold of the film. A cap of porous material is wrapped over the folded edge and is sealed thereto along a continuous line to define an enclosed area on both sides of the edge in which the film and cap are unsealed. An opening, such as a slot, is provided in or adjacent to the fold of the film, with the opening being entirely located within the unsealed area and spaced from the seal line. The construction lessens the possibility of open bacteria paths often found in similar prior art pouches.In the manufacture of the pouch, a web of thermoplastic film is provided with a series of spaced linear openings or slits, a porous sheet material is applied over the openings and the porous material is sealed to the web along a continuous line surrounding the openings.

Abstract: Certain blends or mixtures of polyethylene and ionomer resins are blow extruded to make a film having excellent linear tear properties in the direction of extrusion, which property is not found in films of either of the resins alone.