Easy Peel Film Structures

Abstract

The present invention relates to sealant films comprising a first sealant layer which readily and easily delaminates or peels from a second adjacent film layer. The first sealant layer and the second adjacent layer of the sealant film of the present invention comprise propylene or ethylene moieties wherein the propylene or ethylene moieties may be homopolymers or copolymers. The film structures of the present invention can be used independently, or laminated to a second film structure wherein the second film structure may comprise a single layer or multiple layers. The sealant films of the present invention can be heat sealed to a packaging component, such as a tray either as a single film structure or as a laminate comprising a second film structure. The sealant film structures of the present invention are particularly useful as retortable lidstock.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a division of U.S. application Ser. No. 10 / 359,951, filed Feb. 5, 2003, now allowed, which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION [0002] The present invention relates to improved peelable sealant film structures which are especially suitable for use as lidstock for retortable packages. BACKGROUND OF THE INVENTION [0003] The use of formed trays and peelable lids for those trays, has been known for some time. For example, food products such as microwaveable meals are commonly packaged in packages requiring a peelable lid. These packages are usually subjected to relatively severe processing conditions either at the point where the package is being filled and sealed or at the point where the package and its contents are to be used. In the packaging of food products, it is also desirable to provide lidstock material which will not only protect the food product from outside contaminants ...

AI Technical Summary

Benefits of technology

[0016] The sealant film structures of the present invention are designed to be laminated to a second film structure which can be further heat sealed to a packaging component, such as a tray. The film structures of the present invention are retortable and also are openable by the delamination or peeling away of the film structure of the present invention from the packaging component such as a tray. As the force is exerted to remove the film from the packaging component, the first sealant layer of the film structure of the present invention delaminates or peels away from the second adjacent layer in the area of the sealing interface. It has been found that the peel force required to delaminate or peel away the film structure of the present invention from the a packaging component is surprisingly less than expected. While the peel force has been reduced, the seal strengths and burst force requirements have not been compromised.

Problems solved by technology

These packages are usually subjected to relatively severe processing conditions either at the point where the package is being filled and sealed or at the point where the package and its contents are to be used.

A particular problem is encountered in providing packaging for the severe process conditions of, for example, retort processing or the end use environments, in that there are only a limited number of packaging materials which can be used to provide the combined properties of (i) barrier functions, (ii) the ability to survive the severe processing and use conditions, (iii) safety for use in the packaging of food, and (iv) holding the package closed and containing the product.

The lid cannot, however, be so loosely sealed to the tray that it is inadvertently or otherwise undesirably released from the tray prior to an intentional opening of the package.

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