Packaging dual-ovenable tray

Formed multilayer barrier packages, eg, trays, bowls, and cans from coextruded PP/PVDC/ PP, are being developed for soups and entrees that can be stored at ambient temperatures and heated to serving temperature in a microwave oven. Coextrusions of high performance, high temperature polymers, such as polyether-imide and polysulfone, for dual-oven containers capable of withstanding conventional bake-oven temperatures of 204-232°C are being tested. 

Attention has been paid to the possible use of multilayer coextrusion of engineering resins for dual ovenable containers, as multilayer packaging could increase shelf stability and thus eliminate the need for freezing or refrigeration. One multilayer combination in commercial use is a sheet of Lexan polycarbonate sandwiched between layers of Ultem polyetherimide. Thermoformed trays of this material are reported to have better break resistance at lower temperatures and higher stiffness at temperatures up to 232°C, as compared to CPET. They are also insert, compatible with polyester lidding materials, and have lower oxygen permeability than PET materials. 

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