US 6,333,061 B1Granted

Packaging article

AssigneeCryovac, Inc.

InventorParimal M. Vadhar

Life of this patent

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Abstract

A sealed article comprising a multilayer film having at least 4 layers. The first layer is an inside layer comprising ethylene/alpha-olefin copolymer and/or polystyrene. The second layer comprises ethylene/unsaturated ester copolymer, anhydride-modified ethylene/alpha-olefin copolymer, anhydride-modified ethylene/ester copolymer, acid-modified ethylene/alpha-olefin copolymer, and/or acid-modified ethylene/acid copolymer. The third layer comprises ethylene/alpha-olefin copolymer and/or polystyrene. The fourth layer comprises ethylene homopolymer, ethylene/alpha-olefin copolymer, ethylene/vinyl alcohol copolymer, polyvinylidene chloride, polyamide, polyester, polyalkylene carbonate, polyacrylonitrile, and/or ethylene/unsaturated ester copolymer. At least 85 volume percent of the film is made up of polyolefin homopolymer, polyolefin copolymer, ethylene/ester copolymer, polystyrene, styrene/butadiene copolymer, EVOH, PVDC, and polyacrylonitirile. The film has a total thickness of at least 2 mils, and an impact strength of at least about 1.5 ft-lbs. The article comprises a seal of the film to itself and/or another film. In another article, in which the film has at least 6 layers, the film has a thickness of at least 2 mils and a tear propagation of at least 300 grams.

Claims29

Dependent claims

A sealed article comprising a heat-shrinkable multilayer film which comprises:

(A) a first film layer which is an inside film layer comprising at least one member selected from the group consisting of ethylene/alpha-olefin copolymer and polystyrene;
(B) a second film layer comprising at least one member selected from the group consisting of ethylene/unsaturated ester copolymer, anhydride-modified ethylene/alpha-olefin copolymer, anhydride-modified ethylene/ester copolymer, acid-modified ethylene/alpha-olefin copolymer, acid-modified ethylene/acid copolymer, and polystyrene;
(C) a third film layer comprising at least one member selected from the group consisting of ethylene/alpha-olefin copolymer and polystyrene;
(D) a fourth film layer which comprises at least one member selected from the group consisting of ethylene homopolymer, ethylene/alpha-olefin copolymer, ethylene/vinyl alcohol copolymer, polyvinylidene chloride, polyamide, polyester, polyalkylene carbonate, polyacrylonitrile, and ethylene/unsaturated ester copolymer;
and
wherein at least 85 percent of the film, based on total film volume, consists of at least on member selected from the group consisting of polyolefin homopolymer, polyolefin copolymer, ethylene/ester copolymer, polystyrene, styrene/butadiene copolymer, EVOH, PVDC, and polyacrylonitirile;
wherein the film has a total thickness of at least 2 mils and a tear propagation of 10 to 500 grams per mil, and an impact strength of at least about 1.5 ft-lbs, and a total free shrink, at 180° F., of from about 2 to 50 percent;
and
wherein the article comprises a seal of the film to at least one member selected from the group consisting of itself and another film.

6 more elements

A packaged product comprising a heat-shrinkable multilayer film surrounding a product, wherein the film comprises:

(A) a first film layer which is an inside film layer comprising at least one member selected from the group consisting of ethylene/alpha-olefin copolymer and polystyrene;
(B) a second film layer comprising at least one member selected from the group consisting of ethylene/unsaturated ester copolymer, anhydride-modified ethylene/alpha-olefin copolymer, anhydride-modified ethylene/ester copolymer, acid-modified ethylene/alpha-olefin copolymer, acid-modified ethylene/acid copolymer;
(C) a third film layer comprising at least one member selected from the group consisting of ethylene/alpha-olefin copolymer and polystyrene;
(D) a fourth film layer which is an outside layer comprising at least one member selected from the group consisting of ethylene homopolymer, ethylene/alpha-olefin copolymer, ethylene/vinyl alcohol copolymer, polyvinylidene chloride, polyamide, polyester, polyalkylene carbonate, polyacrylonitrile, and ethylene/unsaturated ester copolymer;
and
wherein at least 85 percent of the film, based on total film volume, consists of at least on member selected from the group consisting of polyolefin homopolymer, polyolefin copolymer, ethylene/ester copolymer, polystyrene, styrene/butadiene copolymer, EVOH, PVDC, and polyacrylonitirile;
wherein the film has a total thickness of at least 2 mils, and a tear propagation of 10 to 500 grams per mil an impact strength of at least about 1.5 ft-lbs, and a total free shrink, at 180° F., of from about 2 to 50 percent;
wherein the article comprises a heat seal of the film to at least one member selected from the group consisting of itself and another film;
and
wherein the product comprises hard, flowable, particulates or non-flowable cheese.

7 more elements

A heat-sealed article comprising a heat-shrinkable multilayer film which comprises:

(A) a first film layer which is an inside film layer comprising at least one member selected from the group consisting of ethylene/alpha-olefin copolymer and polystyrene;
(B) a second film layer which serves as tie layer, and which comprises at least one member selected from the group consisting of ethylene/unsaturated ester copolymer, anhydride-modified ethylene/alpha-olefin copolymer, anhydride-modified ethylene/ester copolymer, acid-modified ethylene/alpha-olefin copolymer, and acid-modified ethylene/acid copolymer;
(C) a third film layer comprising at least one member selected from the group consisting of polyvinylidene chloride, ethylene/vinyl alcohol copolymer, polyalkylene carbonate, and polyacrylonitrile;
(D) a fourth film layer which serves as tie layer, and which comprises at least one member selected from the group consisting of ethylene/unsaturated ester copolymer, anhydride-modified ethylene/alpha-olefin copolymer, anhydride-modified ethylene/ester copolymer, acid-modified ethylene/alpha-olefin copolymer, acid-modified ethylene/acid copolymer;
(E) a fifth film layer comprising at least one member selected from the group consisting of ethylene/alpha-olefin copolymer and polystyrene;
and
(F) a sixth layer which comprising at least one member selected from the group consisting of high density ethylene homopolymer, ethylene/alpha-olefin copolymer, propylene homopolymer, polystyrene, styrene/butadiene copolymer, polystyrene, an propylene;
wherein at least 85 percent of the film, based on total film volume, consists of at least one member selected from the group consisting of polyolefin homopolymer, polyolefin copolymer, ethylene/ester copolymer, polystyrene, styrene/butadiene copolymer, EVOH, PVDC, and polyacrylonitirile;
wherein the film has a total thickness of at least 2 mils, an impact strength of at least about 1.5 ft-lbs, and a tear propagation of at least 300 grams per mil, and a total free shrink, at 180° F., of from about 2 to 50 percent;
and
wherein the article comprises a seal of the film to at least one member selected from the group consisting of itself and another film.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/970,187Filed 14 Nov 1997 · us provisional application
Priority: 22 Nov 1996
Granted: 25 Dec 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification30 codes

B32B 27/08
As the main or only constituent of a layer, which is next to another layer of the same or of a different material: of synthetic resin
B32B 7/12
Interconnection of layers: using interposed adhesives or interposed materials with bonding properties
B32B 27/20
Characterised by the use of special additives: using fillers, pigments, thixotroping agents
B32B 27/302
Comprising vinyl polymers; comprising acrylic polymers: comprising aromatic vinyl polymers, e.g. styrenic polymers