摘要 |
Multiple ply packaging materials formed of an inner ply of substrate material superimposed between outer plies of thermoplastic films exhibit excellent gas barrier properties. The inner ply may comprise any suitable material such as nylon, but for significantly improved gas barrier properties preferably comprises either a plastic film having a metal coating on one or both surfaces thereof, or a metal foil. The inner ply is encapsulated between the outer thermoplastic plies to isolate the inner ply from the contents of the package, especially when the material is exposed to or is employed to package liquids, the outer plies of thermoplastic film being sealed about their edges outwardly from the edges of the inner ply. |