IMPROPER HANDLING-RESISTANT WRAPPING FILM CAPABLE OF WITHSTANDING STERILISATION IN AUTOCLAVE, HAVING OXYGEN IMPERMEABLE LAYER AND CONTAINING MIXTURE OF AMORPHOUS POLYAMIDE AND POLYCRYSTALLINE POLYAMIDE Russian patent published in 2011 - IPC B32B27/08 B32B27/06 B32B27/34 B65D81/34 C08J5/18 

FIELD: chemistry.

SUBSTANCE: method involves: (A) putting a product in a packing article, containing a multilayer wrapping film welded onto itself, (B) heat sealing the closed product so that the product is surrounded by the multilayer wrapping film; (C) heating the packed product to temperature of at least 212°F for at least approximately 0.5 hours, where heating takes place in the presence of vapour under pressure. The multilayer wrapping film contains: (1) a cross-linked first outer layer which serves as an insulating layer and the in contact with the product, and (2) a cross-linked O₂-impermeable layer containing a mixture of: (i) 50-95 wt % in terms of the weight of the mixture of amorphous polyamide, which contains at least one polyamide selected from a group comprising PA-6I/6T; PA-MXD,I/6,I; PA-6/6,T; PA-6/6I; PA-6,6/6,I; PA-6,6/6,T; and (ii) polycrystalline polyamide which contains at least one polyamide selected from a group consisting of (a) 5-50% of the weight of the PA-MXD,6/MXD,I mixture and (b) 5-15% of the weight of the mixture, polyamide with or without a nucleating agent, having reduced viscosity measured in accordance with the ISO 307 test method from 150 ml/g to 245 ml/g.

EFFECT: obtaining a packed food product sterilised in an autoclave and having a long shelf life.

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