Easy open bag and film for use in thermally processing food at elevated temperatures

A multilayer heat-shrinkable film for forming a cook-in bag, the film comprising:

• at least five layers arranged in sequence and in contact with one another comprising:
• (a) a first, inner layer comprising at least 50 wt % of at least one material independently selected from the following:
• polyethylenes, polypropylenes, ethylene/α-olefin copolymers having at least one C3 to C10 α-olefin, propylene/ethylene copolymers, ethylene/vinyl acetate copolymers, polyamides, polyesters, polyvinyl chlorides, ionomers, and mixtures thereof,
• (b) a second, inner frangible layer comprising approximately 0.1-30 wt % polybutene,
• (c) a third, barrier layer comprising approximately 90-100 wt % of an ethylene vinyl alcohol copolymer having an ethylene content between approximately 38-44 mol %,
• (d) a fourth, outer frangible layer comprising approximately 0.1-30 wt % polybutene, and
• (e) a fifth, outer, layer comprising at least 50 wt % of at least one material independently selected from the following:
• polyethylenes, polypropylenes, ethylene/α-olefin copolymers having at least one C3 to C10 α-olefin, propylene/ethylene copolymers, ethylene/vinyl acetate copolymers, polyamides, polyesters, polyvinyl chlorides, ionomers, and mixtures thereof.

An individual bag comprising:

• a multilayer heat-shrinkable film comprising:
• (a) an inner heat sealing layer,
• (b) an outer heat sealing layer,
• (c) an oxygen barrier layer positioned between the inner heat sealing layer and outer heat sealing layer,
• (d) an inner frangible layer positioned between the inner heat sealing layer and the oxygen barrier layer, and
• (e) an outer frangible layer positioned between the outer heat sealing layer and the oxygen barrier layer;
• wherein the film has an oxygen gas transmission rate of less than about 70 cm3/m2 for a 24 hour period at 1 atmosphere, 0% relative humidity, and 23° C.;
• wherein the film has a shrinkage value of at least 10% in both machine and transverse directions at 90° C.;
• the film being formed into a bag defined by:
• a lap seal connecting the inner heat sealing layer to the outer heat sealing layer, the lap-sealed film defining a flattened tube member having a first end and an opposing second end, a first bag wall and an opposing second bag wall, and a first bag edge and opposing second bag edge each extending between the first end and the second end of the flattened tube member;
• and
• a first end seal connecting the inner heat sealing layer on the first bag wall with the inner heat sealing layer on the second bag wall between the first and second bag edges proximate to the first end of the tube member;
• and
• wherein the film has a shrink force, the lap seal has a lap seal shear strength, and the first end seal has a first end seal peel strength, where both the lap seal shear strength and the first end seal peel strength are greater than the shrink force of the film at approximately 73° C.;
• wherein the lap seal is peelable along a lap seal interface located between the outer heat sealing layer and the outer frangible layer, where the lap seal has a lap seal peel strength of about 250 to about 3000 grams per inch;
• and
• wherein the first end seal is peelable along a first end seal interface located between the inner heat sealing layer and the inner frangible layer, where the first end peel strength is about 1400 to about 3000 grams per inch.