Oriented polymeric films, packaging made from such films and methods of making the films and packaging.

摘要

Molecularly oriented plastic films have five layers simultaneously molecularly oriented. The films are made by coextruding and have a first layer which provides a barrier to gaseous transmission through the film and has a composition of 0% to 50% nylon or nylon copolymer, and 50% to 100% ethylene vinyl alcohol. Second and third adhesive layers are each adhered to a respective one of the surfaces of the first layer, and have compositions comprising olefinic polymers, copolymers or blends thereof, the compositions all having carboxyl modifications therein. Fourth and fifth layers are respectively adhered to the second and third layers on their respective surfaces opposite the first layer, the fourth and fifth layers comprising 40% to 100% ethylene vinyl acetate and 0% to 60% linear low density polyethylene. After extruding the films, they are heated to molecular orientation temperature and are stretched, for example using the gas bubble technique when the film is extruded through an annular die. Heat sealable bags of pouch form are made from juxtaposed sheets or portions of film, or from a film of tubular form, by one or more peripheral heat seals as appropriate, leaving the bag open along one part of its periphery for filling and subsequent closure by a heat seal.