Abstract: A thermoplastic container, which is particularly useful for packaging meat, comprises a first polymeric layer, a second intermediate or tie layer, and a third polymeric layer. The first layer comprises an alkylene terephthalate or naphthalate polymer such as polyethylene terephthalate (PET). The first layer can include, in whole or in part, one or more homo-polymers, co-polymers, recycled polymers, or reprocessed polymers. The third layer comprises a non-polar thermoplastic such as high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or a blend thereof. The intermediate layer primarily functions as an adhesive and as a compatibilizer/emulsifier/surfactant (CES), and comprises a grafted or backbone-based co-polymer or ter-polymer of ethylene, glycidyl acrylate or maleic anhydride, and optionally an acrylate co-monomer.

Abstract: Thermoplastic compositions comprising a bulk polymer, an additive, and a compatibilizer/emulsifier/surfactant (CES) are described. The bulk polymer comprises an alkylene terephthalate or naphthalate polyester such as polyethylene terephthalate. The additive comprises an amorphous or substantially amorphous co-polymer of ethylene and a co-monomer that forms polar portions, such as methacrylate, butylacrylate, ethyl acrylate, or ethylhexyl methacrylate. The CES comprises a co-polymer or ter-polymer of ethylene and a glycidyl acrylate or maleic anhydride, and optionally an acrylate such as methacrylate, ethylacrylate, propylacrylate, butylacrylate, ethylhexylacrylate, or mixtures thereof. The thermoplastic compositions of the present invention exhibit improved molding properties, high dimensional stability, high temperature resistance, and are particularly useful in food-grade applications such as dual-ovenable containers.

Abstract: An apparatus for thermoforming a thermoplastic article comprises an extrusion die for extruding a sheet of thermoplastic and a rotating wheel having at least one mold member. The mold member includes a male mold or forming cavity for receiving at least a portion of a substantially non-oriented (i.e., non-tensioned) thermoplastic sheet. The mold member is selectively heated and/or cooled during thermoforming to maintain the sheet in a molten or thermoformable state. The mold member also comprises a stripper plate maintained at a predetermined temperature or temperature distribution for inducing a predetermined degree of crystallinity to the sheet. The stripper plate enables the articles to be separated from the mold without distortion. In one embodiment, the thermoformed article has at least two and preferably at least three distinct regions of thermally-induced crystallinity.

Abstract: Polyester composition with improved impact properties, improved oxygen permeability and improved dimensional shrinkage during heating. Impact modifiers are dissolved into a molten polyester to form a eutectic alloy. On slow cooling, the eutectic alloy of the invention freezes to form a mixture of particles of the impact modifier embedded in a matrix of the polyester. By controlling the solidification of the melt, the size and distribution of the precipitates from the melt can be controlled, which allows control of the mechanical properties. The precipitation can also be controlled either by homogenous nucleation or by heterogeneous nucleation through the addition of a nucleating agent or the introduction of a suitable surface for nucleation. The invention also provides a process of manufacturing the above polyester, an article comprising this polyester and a process for making this article.

Abstract: Polyester composition with improved impact properties, improved oxygen permeability and improved dimensional shrinkage during heating. Impact modifiers are dissolved into a molten polyester to form a eutectic alloy. On slow cooling, the eutectic alloy of the invention freezes to form a mixture of particles of the impact modifier embedded in a matrix of the polyester. By controlling the solidification of the melt, the size and distribution of the precipitates from the melt can be controlled, which allows control of the mechanical properties. The precipitation can also be controlled either by homogenous nucleation or by heterogeneous nucleation through the addition of a nucleating agent or the introduction of a suitable surface for nucleation. The invention also provides a process of manufacturing the above polyester, an article comprising this polyester and a process for making this article.

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.