Abstract: In a multi-layer polymeric structure having an interior oxygen barrier layer of a moisture sensitive polymeric material such as ethylene-vinyl alcohol, drying agents are incorporated in the structure, particularly in a layer or layers proximate to the barrier layer, to limit the moisture content of the barrier layer to maintain barrier properties.

Abstract: This application is concerned with food packages made from sheet or film into the forms of heat sealable pouches, bags, or covered trays in which the food product is placed, the package sealed, and the packaged food processed in a pressure cooker or retort to permit the packaged food to be stored without refrigeration. Certain food products can be rendered commercially sterile by hot filling the package at temperatures below boiling to permit storage for long periods without refrigeration. While still in the sealed package of the present invention, the consumer can heat or cook the food by immersion in boiling water or by microwave oven. The sheet or film is a multilayer construction wherein each layer performs specific functions and the choice of materials for the layers is interdependent to provide a film structure having all desired properties at the least cost.

Abstract: A molecularly oriented article having a tubular sidewall is blow-molded from a thermoplastic parison which is heat-treated prior to blowing to provide the parison sidewall with a temperature gradient wherein the temperature of the inside of the sidewall is greater than that of the outside, both of said temperature being within the orientation temperature range of the thermoplastic. The temperature gradient results in the sidewall of the article having a different and more uniform circumferential orientation release stress distribution radially across the sidewall than would be obtained if the parison were blown isothermally.