Delamination-Resistant Heat-Shrinkable Multilayer Oxygen Barrier Film Containing Polyester

A process for packaging a food product comprising the steps of:

• (A) providing a multilayer heat shrinkable film;
• the multilayer heat-shrinkable film comprising:
• a. a first layer comprising a first polyester, the first layer being an outer layer;
• b. a second layer which serves as a heat seal layer, the second layer being an outer layer;
• c. a third layer which serves as an O2-barrier layer, the third layer comprising at least one member selected from the group consisting of saponified ethylene/vinyl acetate copolymer, polyamide MXD6, polyamide 6I/6T, polyamide 6, polyvinylidene chloride, polyethylene naphthalate, polytrimethylene terephthalate, liquid crystal polymer, and O2-scavenger;
• d. a fourth layer which serves as a tie layer directly adheared to both the first layer and the third layer, the fourth layer comprising a blend of:
• i. a modified polyolefin;
• ii. a styrene-based polymer;
• and
• iii. a second polyester,
• e. wherein the multilayer heat shrinkable film exhibits a total free shrink at 85° C. of at least 10% measured in accordance with a modified free shrink test otherwise in accordance with ASTM D 2732, and the first polyester is present in the film in an amount of at least 2 vol %, based on total film volume
• (B) forming the multilayer heat shrinkable film into a packaging article or utilizing the film in a flow wrap process to produce a partially packaged product comprising a backseamed packaging article having a bottom seal and an open top, the packaging article having a product therein;
• (C) evacuating atmosphere from within the packaging article and sealing the the packaging article closed so that the product is surrounded by the packaging article;
• and
• (D) shrinking the packaging article around the product.