Process for manufacturing thermoplastic compositions and containers made of such compositions
AssigneeAto Chimie
InventorSimon Kornbaum
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Abstract
A process for manufacturing thermoplastic materials having an elevated gas impermeability and/or improved physical properties. This process is characterized in that it comprises mixing at least partially imcompatible polymers, gelling them by the combined action of heat, pressure and kneading. The gelled mixture is then subjected to laminar flow through substantially parallel surfaces in which the ratio of the length of the surfaces to the distance between them is greater than 10. A thermoplastic material having increased gas impermeability as well as containers made out of said materials. A packaging method in which the thermoplastic materials of the invention are used to package oxygen sensitive materials.
Claims8
An extruded sheet-like thermoplastic material having reduced permeability comprising a continuous phase consisting essentially of polyvinyl chloride, and a discontinuous phase, consisting essentially of polyvinyl alcohol, incompatible with the polyvinyl chloride phase, wherein said discontinuous polyvinyl alcohol phase is in the form of lamellar layers distributed in the continuous polyvinyl chloride phase parallel to the surface of said sheet-like material and wherein the ratio by weight of the polyvinyl chloride to the polyvinyl alcohol is from 100:1 to 1:1 produced by extruding a mixture of polyvinyl chloride and polyvinyl alcohol through a die defining an extrusion channel having mutually opposed parallel die surfaces wherein the ratio of the length of said channel in the direction of flow of the material being extruded to the distance between the opposed surface which determines the thickness of the sheet-like material is greater than 10.
Dependencies are inferred from the claim text.