Process for producing irradiated multilayer film for primal meat packaging

Claim 2

A process for producing a multilayer film suitable for packaging primal and sub-primal meat cuts and processed meats comprising: (a) co-extruding a multilayer film first outer film layer comprising a first ethylene-vinyl acetate copolymer, a core film layer comprising polyvinylidene chloride-vinyl chloride copolymer containing between about 70 weight percent and about 90 weight percent vinylidene chloride as a barrier, and a second outer film layer comprising a second ethylene-vinyl acetate copolymer; (b) biaxially stretching said multilayer film; and (c) substantially uniformly irradiating the entire multilayer film to a dosage level of between about 2 megarads and about 3 megarads, whereby said multilayer film is not significantly discolored by the irradiation and is able to withstand higher sealing temperatures than a similar film which has not been so irradiated.

Claim 3

A process in accordance with claim 1 wherein said first ethylene-vinyl acetate copolymer has a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 9 to about 15 weight percent, based on the weight of said first ethylene-vinyl acetate copolymer.

Claim 4

A process in accordance with claim 1 wherein said first ethylene-vinyl acetate copolymer is selected from the group consisting of (a) a single ethylene-vinyl acetate copolymer, and (b) a blend of ethylene-vinyl acetate copolymers having differing melt indices and differing vinyl acetate contents.

Claim 5

A process in accordance with claim 1 wherein said polyvinylidene chloride copolymer contains a maximum of 5 weight percent plasticizer, based on the weight of said polyvinylidene chloride copolymer.

Claim 6

A process in accordance with claim 1 wherein said second outer layer comprises a second ethylene-vinyl acetate copolymer having a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 9 to about 18 weight percent, based on the weight of said second ethylene-vinyl acetate copolymer.

Claim 7

A process in accordance with claim 1 wherein said second layer comprises a second ethylene-vinyl acetate copolymer having a vinyl acetate content of from about 10 to about 15 weight percent, based on the weight of said copolymer.

Claim 8

A process in accordance with claim 1 wherein said second ethylene-vinyl acetate copolymer comprises a blend of at least two ethylene-vinyl acetate copolymers, wherein one of said ethylene-vinyl acetate copolymers has a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 10 to about 18 weight percent, based on the weight of said copolymer, and one of said ethylene-vinyl acetate copolymers has a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 2 to about 10 weight percent, based on the weight of said copolymer.

Claim 9

A process in accordance with claim 7 wherein said blend of said second ethylene-vinyl acetate copolymers has a vinyl acetate content of from about 9 to about 18 weight percent, based on the weight of said blend of ethylene-vinyl acetate copolymers.

Claim 10

A process in accordance with claim 1 wherein said first outer layer has a thickness from about 1.1 mils to about 1.6 mils.

Claim 11

A process in accordance with claim 1 wherein said first core layer has a thickness of from about 0.25 mil to about 0.45 mil.

Claim 12

A process in accordance with claim 1 wherein said second outer layer has a thickness of from about 0.4 mil to about 1.0 mil.

Claim 13

A process in accordance with claim 1 wherein said multilayer film has a total thickness of from about 1.75 mils to about 3.0 mils.

Claim 14

A process in accordance with claim 1 including fabricating said multilayer film into the form of a bag.

Claim 15

A process in accordance with claim 1 wherein said co-extrusion of said film layers produces a multilayer film sheet.

Claim 16

A process in accordance with claim 1 wherein said co-extrusion of said film layers produces a multilayer tubular film.

Claim 17

A process for producing a multilayer film suitable for packaging primal and sub-primal meat cuts and processed meats comprising: (a) co-extruding a first outer film layer comprising a first ethylene-vinyl acetate copolymer having a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 9 to about 15 weight percent, based on the weight of said first ethylene-vinyl acetate copolymer, said first ethylene-vinyl acetate copolymer being selected from the group consisting of (a) a single ethylene-vinyl acetate copolymer, and (b) a blend of ethylene-vinyl acetate copolymers having differing melt indices and differing vinyl acetate contents; a core film layer comprising polyvinylidene chloride-vinyl chloride copolymer containing between about 70 weight percent and about 90 weight percent vinylidene chloride; and a second outer film layer comprising a second ethylene-vinyl acetate copolymer selected from the group consisting of (a) an ethylene-vinyl acetate copolymer having a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 9 to about 18 weight percent, based on the weight of said second ethylene-vinyl acetate copolymer, and (b) a blend of at least two ethylene-vinyl acetate copolymers, wherein one of said ethylene-vinyl acetate copolymers has a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 10 to about 18 weight percent, based on the weight of said copolymer, and the other ethylene-vinyl acetate copolymer has a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 2 to about 10 weight percent, based on the weight of said copolymer; (b) biaxially stretching said multilayer film; and (c) substantially uniformly irradiating the entire multilayer film to a dosage level of between about 2 megarads and about 3 megarads, whereby said multilayer film is not significantly discolored by the irradiation and is able to withstand higher sealing temperatures than a similar film which has not been so irradiated.

Claim 18

A process for producing a multilayer film suitable for packaging primal and sub-primal meat cuts and processed meats comprising: (a) co-extruding a first outer film layer comprising a first ethylene-vinyl acetate copolymer having a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 9 to about 15 weight percent, based on the weight of said first ethylene-vinyl acetate copolymer, said first ethylene-vinyl acetate copolymer being selected from the group consisting of (a) a single ethylene-vinyl acetate copolymer, and (b) a blend of ethylene-vinyl acetate copolymers having differing melt indices and differing vinyl acetate contents; a core film layer comprising polyvinylidene chloride-vinyl chloride copolymer containing between about 70 weight percent and about 90 weight percent vinylidene chloride; and a second outer film layer comprising a second ethylene-vinyl acetate copolymer selected from the group consisting of (a) an ethylene-vinyl acetate copolymer having a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 9 to about 18 weight percent, based on the weight of said second ethylene-vinyl acetate copolymer, and (b) a blend of at least two ethylene-vinyl acetate copolymers, wherein one of said ethylene-vinyl acetate copolymers has a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 10 to about 18 weight percent, based on the weight of said copolymer, and the other ethylene-vinyl acetate copolymer has a melt index of from about 0.1 to about 1.0 decigram per minute and a vinyl acetate content of from about 2 to about 10 weight percent, based on the weight of said copolymer; (b) biaxially stretching said multilayer film; and (c) substantially uniformly irradiating the entire multilayer film to a dosage level of between about 2 megarads and about 3 megarads, whereby said multilayer film is not significantly discolored by the irradiation and is able to withstand higher sealing temperatures than a similar film which has not been so irradiated.

Claim 19

A process in accordance with claim 16 wherein said polyvinylidene chloride copolymer contains a maximum of 5 weight percent plasticizer, based on the weight of said polyvinylidene chloride copolymer.

Claim 20

A process in accordance with claim 16 wherein said second outer layer comprises a second ethylene-vinyl acetate copolymer having a vinyl acetate content of from about 10 to about 15 weight percent, based on the weight of said copolymer.

Claim 21

A process in accordance with claim 16 wherein said blend of said second ethylene-vinyl acetate copolymers has a vinyl acetate content of from about 9 to about 18 weight percent, based on the weight of said blend of ethylene-vinyl acetate copolymers.

Claim 22

A process in accordance with claim 16 wherein said first outer layer has a thickness from about 1.1 mils to about 1.6 mils.

Claim 23

A process in accordance with claim 16 wherein said core layer has a thickness of from about 0.25 mil to about 0.45 mil.

Claim 24

A process in accordance with claim 16 wherein said second outer layer has a thickness of from about 0.4 mill to about 1.0 mil.

Claim 25

A process in accordance with claim 16 wherein said multilayer film has a total thickness of from about 1.75 mils to about 3.0 mils.

Claim 26

A process in accordance with claim 16 including fabricating said multilayer film into the form of a bag.

Claim 27

A process in accordance with claim 16 wherein said co-extrusion of said film layers produces a multilayer film sheet.

Claim 28

A process in accordance with claim 16 wherein said co-extrusion of said film layers produces a multilayer tubular film.

Claim 29

A process for producing a multilayer film suitable for packaging primal and sub-primal meat cuts and processed meats comprising: (a) co-extruding a multilayer film first outer layer film layer, a core film layer comprising polyvinylidene chloride-vinyl chloride copolymer containing between about 70 weight percent and about 90 weight percent vinylidene chloride as a barrier, and a second outer film layer; (b) biaxially stretching said multilayer film; and (c) substantially uniformly irradiating the entire multilayer film to a dosage level of between about 2 megarads and about 3 megarads, whereby said multilayer film is not significantly discolored by the irradiation and is able to withstand higher sealing temperatures than a similar film which has not been so irradiated.

Claim 30

A process for producing a multilayer film suitable for packaging primal and sub-primal meat cuts and processed meats comprising: (a) co-extruding a multilayer film first outer layer film layer, a core film layer comprising polyvinylidene chloride-vinyl chloride copolymer containing between about 70 weight percent and about 90 weight percent vinylidene chloride as a barrier, and a second outer film layer; (b) biaxially stretching said multilayer film; and (c) substantially uniformly irradiating the entire multilayer film to a dosage level of between about 2 megarads and about 3 megarads, whereby said multilayer film is not significantly discolored by the irradiation and is able to withstand higher sealing temperatures than a similar film which has not been so irradiated.