Abstract: Apparatus for producing an ovenable shaped article of polyethylene terephthalate wherein the polyethylene terephthalate is heated to a temperature in which it is in a thermoformable plastic state, formed as a sheet, locally cooled to form a skin on the surface of the sheet whale maintaining the sheet as a whole in the thermoformable plastic state and vacuum forming the shaped article within cavities on a rotating drum. The cavities are additionally provided with controlled heaters to heat the shaped article to impart thereto a degree of crystallinity of at least about 20% and the sheet is laterally and longitudinally tensioned after removal from the drum to prevent distortion.

Abstract: The invention provides a process of manufacturing a shaped polyester article having an oxygen permeability of from about 0.2 to about 4.9 cc-mil/100 in.sup.2 -24 hr-atm at a temperature of 23.degree. C. and at 100% relative humidity inside and 60% relative humidity outside, and an enthalpy of recrystallization of from about 0 to about -2.1 cal/g, as well as a linear dimensional shrinkage between about 0% and 6% when heated from about -60.degree. C. to about 200.degree. C. The crystalline polyester articles are useful as containers for microwavable, ovenable and/or frozen foods, and have good gas barrier properties, and post-mold dimensional stability from about -60.degree. C. to about 200.degree. C.

Abstract: The invention provides for crystalline polyester articles of manufacture having an oxygen permeability of from about 0.2 to about 4.9 cc-mil/100 in.sup.2 -24 hr-atm at a temperature of 23.degree. C. and at 100% relative humidity inside and 60% relative humidity outside, and an enthalpy of recrystallization of from about 0 to about -2.1 cal/g, as well as a linear dimensional shrinkage between about 0% and 6% when heated from about -60.degree. C. to about 200.degree. C. These articles are useful as containers for microwavable, ovenable and/or frozen foods, and have good gas barrier properties, and post-mold dimensional stability from about -60.degree. C. to about 200.degree. C.

Abstract: The invention provides a polyester having an oxygen permeability of from about 0.2 to about 4.9 cc-mil/100 in.sup.2 -24 hr-atm at a temperature of 23.degree. C. and at 00% relative humidity inside and 60% relative humidity outside, and an enthalpy of recrystallization of from about 0 to about -2.1 cal/g, as well as a linear dimensional shrinkage between about 0% and 6% when heated from about -60.degree. C. to about 200.degree. C. The invention also provides a process of manufacturing the above polyester, an article comprising this polyester and a process for making this article. The crystalline polyester article is useful as a container for microwavable, ovenable and/or frozen foods, and has good gas barrier properties, and post-mold dimensional stability from about -60.degree. C. to about 200.degree. C.