Container with improved heat shrunk cellular sleeve

Abstract

There is disclosed herein improved packages, and methods of forming same, of the type wherein a container, such as for example a glass container, like a bottle or jar, is provided externally thereof with a heat shrunk, cellular thermoplastic member, circumferentially and snugly engaging a sidewall portion of the container; the improvement resides in employing as the thermoplastic member a composite structure, or laminate, of a closed cellular polymeric layer in which the polymer is a polymer of predominantly olefin moieties and, in adhered relationship to the closed cellular layer, a non-cellular polymeric layer in which the polymer is a polymer of predominantly olefin moieties with the cellular layer being in snug, heat shrunk engagement with the sidewall portion of the container and the non-cellular layer being disposed outwardly of the cellular layer.

I claim: 
     
       1. In an article of manufacture comprising a container having a sidewall and further including a heat shrunk, polymeric seamed sleeve disposed circumferentially outwardly of said sidewall and in snug engagement therewith, the improvement wherein said polymeric sleeve is a composite structure of a closed cellular polyethylene layer and a non-cellular polyethylene layer in adhering contact with said cellular layer, .Iadd.said composite structure having been formed by blown bubble co-extrusion with a blow-up ratio of about 2:1 or less and having a machine direction heat-shrinkage of at least 50% and a cross-diameter heat-shrinkage of 20% or less, .Iaddend.said cellular layer being in engagement with said sidewall and said non-cellular layer being disposed outwardly of said cellular layer. 
     
     
       2. The improvement of claim 1 wherein said sleeve consists essentially of said two layers, has a density of about 10 to about 40 pounds per cubic foot and a thickness of about 101/2 to 34 mils and wherein said polyethylene of said cellular and said non-cellular layer being independently selected from the group consisting of high density, low density, medium density polyethylene and blends thereof. 
     
     
       3. In an article of manufacture comprising a container having a sidewall and further including a heat shrunk, polymeric sleeve disposed circumferentially outwardly of said wall and in snug engagement therewith, the improvement wherein said polymeric sleeve is a composite structure consisting essentially of two layers, one of said layers being a closed cellular polymeric layer, said polymeric layer being at least 60% by weight of polymerized moieties of an olefin, selected from the group consisting of ethylene, propylene, butene-1 or mixtures thereof and the other of said layers being a non-cellular polymeric layer, said latter polymeric layer being at least 60% by weight of polymerized moieties of an olefin selected from the group consisting of ethylene, propylene, butene-1 or mixtures thereof, .Iadd.said composite structure having been formed by blown bubble co-extrusion with a blow-up ratio of about 2:1 or less and having a machine direction heat-shrinkage of at least 50% and a cross-direction heat-shrinkage of 20% or less, the heat-shrinkage of said sleeve in the circumferential direction corresponding to the machine direction heat shrinkage and the heat shrinkage of said sleeve in the axial direction corresponding to the cross-direction heat shrinkage, .Iaddend.and wherein said cellular layer is in engagement with said sidewall and said non-cellular layer being disposed outwardly of said cellular layer and in adhering contact therewith. 
     
     
       4. The improvement of claim 3 wherein one of said layers consists essentially of polymerized ethylene moieties and polymerized moieties of a vinyl ester of a saturated carboxylic acid and wherein said vinyl ester moiety is less than about 15 weight percent and the ethylene moiety is in excess of about 85 weight percent. 
     
     
       5. The improvement of claim 4 wherein said vinyl ester is vinyl acetate. 
     
     
       6. The improvement of claim 5 wherein the moiety of said vinyl acetate is less than about 10% by weight. 
     
     
       7. The improvement of claim 6 wherein the other of said layers consists essentially of polyethylene. 
     
     
       8. The improvement of claim 3 wherein one of said layers consists essentially of polymerized ethylene moieties and polymerized moieties of an alpha-beta monoethylenically unsaturated carboxylic acid, wherein the ethylene moiety is at least about 65 weight percent and wherein the alpha-beta monoethylenically unsaturated carboxylic acid moiety is less than about 35 weight percent and wherein said other layer consists essentially of polyethylene. 
     
     
       9. The improvement of claim 3 wherein one of said layers consists essentially of polymerized ethylene moieties and polymerized moieties of an alkyl ester of an alpha-beta monoethylenically unsaturated carboxylic acid, wherein the ethylene moiety is at least about 75 weight percent and wherein the moiety of the alkyl ester of an alpha-beta monoethylenically unsaturated carboxylic acid is less than about 25 weight percent and wherein said other layer consists essentially of polyethylene. 
     
     
       10. The improvement of claim 3 wherein at least one of said layers consists essentially of polypropylene. 
     
     
       11. In a method wherein a heat shrinkable, polymeric sheet is formed into a sleeve having a heat sealed overlapped seam and having a major heat shrinkage circumferentially of said sleeve and said sleeve is telescopically located about the sidewall of a container, and heat shrunk into snug engagement with said sidewall, the improvement wherein said polymeric sheet is a coextruded composite structure consisting essentially of two layers, one of said layers being a closed cellular polyethylene layer and the other being a non-cellular polyethylene layer in adhering contact with said cellular polyethylene layer, .Iadd.said composite structure having been formed by blown bubble co-extrusion with a blow-up ratio of about 2:1 or less and having a machine direction heat shrinkage of at least 50% and a cross-direction heat shrinkage of 20% or less, .Iaddend.said cellular layer being brought into engagement with said wall and said non-cellular layer being disposed outwardly of said cellular layer and wherein the circumferential direction of said sleeve corresponds to the machine direction of coextrusion. 
     
     
       12. In a method wherein a heat shrinkable polymeric sheet is formed into a sleeve having a major heat shrinkage circumferentially of said sleeve and said sleeve is telescopically located about the sidewall of a container and heat shrunk into snug engagement with said sidewall, the improvement wherein said polymeric sheet is a composite structure consisting essentially of two layers, one of said layers being a closed cellular polymeric layer, said polymeric layer being at least 60% by weight of polymerized moieties of an olefin, selected from the group consisting of ethylene, propylene, butene-1 or mixtures thereof and the other of said layers being a non-cellular polymeric layer, said latter polymeric layer being in adhering contact with said cellular layer, said non-cellular polymeric layer being at least 60% by weight of polymerized moieties of an olefin selected from the group consisting of ethylene, propylene, butene-1 or mixtures thereof, .Iadd.said composite structure having been formed by blown bubble co-extrusion with a blow-up ratio of about 2:1 or less and having a machine direction heat shrinkage of at least 50% and a cross-direction heat shrinkage of 20% or less, the heat shrinkage of said sleeve in the circumferential direction corresponding to the machine direction heat shrinkage and the heat shrinkage of said sleeve in the axial direction corresponding to the cross-direction heat shrinkage, .Iaddend.and wherein said cellular layer is brought into snug heat shrunk engagement with said sidewall and said non-cellular layer being disposed outwardly of said cellular layer. 
     
     
       13. The improvement of claim 12 wherein one of said layers consists essentially of polymerized ethylene moieties and polymerized moieties of a vinyl ester of a saturated carboxylic acid and wherein said vinyl ester moiety is less than about 15 weight percent and the ethylene moiety is in excess of about 85 weight percent. 
     
     
       14. The improvement of claim 13 wherein said vinyl ester is vinyl acetate. 
     
     
       15. The improvement of claim 14 wherein the moiety of said vinyl acetate is less than about 10%. 
     
     
       16. The improvement of claim 15 wherein the other of said layers consists essentially of polyethylene. 
     
     
       17. The improvement of claim 12 wherein one of said layers consists essentially of polymerized ethylene moieties and polymerized moieties of an alpha-beta monoethylenically unsaturated carboxylic acid wherein the ethylene moiety is at least about 65 weight percent and wherein the alpha-beta monoethylenically unsaturated carboxylic acid moiety is less than about 35 weight percent and wherein said other layer consists essentially of polyethylene. 
     
     
       18. The improvement of claim 13 wherein one of said layers consists essentially of polymerized ethylene moieties and polymerized moieties of an alkyl ester of an alpha-beta monoethylenically unsaturated carboxylic acid, wherein the ethylene moiety is at least about 75 weight percent and wherein the moiety of the alkyl ester of an alpha-beta monoethylenically unsaturated carboxylic acid is less than about 25 weight percent and wherein said other layer consists essentially of polyethylene. 
     
     
       19. The improvement of claim 12 wherein at least one of said layers consists essentially of polypropylene. 
     
     
       20. The improvement of claim 11 wherein said sheet has a density of about 10 to about 40 pounds per cubic foot and a thickness of about 101/2 to about 34 mils and wherein said polyethylene of said cellular and said non-cellular layer is independently selected from the group consisting of high density, low density, medium density polyethylene and blends thereof. 
     
     
       21. The article of claim 1 wherein said container is a glass container. 
     
     
       22. The method of claim 12 wherein said container is a glass container.