High temperature resistant hermetically sealed plastic tray packages
AssigneeStandard Packaging Corporation
InventorsArthur Hirsch, Francis X. Spiegel
Life of this patent
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Abstract
A package capable of withstanding prolonged exposure to temperatures in excess of 300.degree. F is formed from a composite film which includes a thermostable, thermoplastic layer and a polyolefin layer having a softening point below 300.degree. F. The package is hermetically sealed although it may include a weakened seal area which acts as a pressure relief valve, and may be employed as a serving dish as well as a heating container.
Claims5
A hermetically sealed plastic package for use at temperatures above 300.degree. F. comprising a semi-rigid tray member and a flexible lid member sealed together to form a cavity between them, an article to be heated to temperatures above 300.degree. F. in said cavity, said tray member and said lid member each being formed from a laminate film and each member comprising an outer thermoplastic film layer selected from the group consisting of polycarbonate, polypentamethylene homo- and co-polymers and polysulfone films and an inner polyolefin film layer, said thermoplastic film layer being thermostable at temperatures above 300.degree. F., said polyolefin film layer having a softening point greater than 180.degree. F. but less than 300.degree. F., a hermetic seal between the polyolefin film layer of said tray member and the polyolefin film layer of said lid member, said package being capable of withstanding exposure to a temperature in the range of 300.degree. F. to 450.degree. F. for a period of at least 15 minutes without losing its shape or its integrity.
Dependencies are inferred from the claim text.