Non-foil composite structures for packaging juice

Abstract

The present invention relates to a non-foil composite barrier .Iadd.structure .Iaddend.for an improved container for citrus juices and other liquids. The container utilizes a paperboard barrier laminate for the containment of essential oils and the prevention of losses of vitamin C. Also disclosed is a process of making the laminate. The laminate makes use of .[.an inner.]. .Iadd.a buried .Iaddend.barrier layer of a heat-sealable ethylene vinyl alcohol copolymer to enhance the barrier properties of the laminate.

What is claimed is: 
     
       1. A container for liquids containing essential oils and flavors, .Iadd.said container having an interior and an exterior, .Iaddend.said container constructed from a laminate comprising: (a) a paperboard substrate .Iadd.with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface.Iaddend.;   (b) a 12 lb. outer layer of a heat-sealable low density polyethylene polymer .[.coated on.]. .Iadd.exterior to .Iaddend.to said outer surface of said paperboard substrate;   (c) .[.an inner.]. .Iadd.a coextruded .Iaddend.sandwich layer comprising a 4.5 lb. tie layer, a 4.0 lb. heat-sealable ethylene vinyl alcohol copolymer layer and a 4.5 lb. tie layer .[.extruded on.]. .Iadd.interior to .Iaddend.said inner surface of said paperboard substrate; and   (d) a product-contact layer of a 10 lb. heat-sealable low density polyethylene polymer .[.coextruded onto.]. .Iadd.interior to .Iaddend.said outer surface of said inner sandwich layer of tie layer--ethylene vinyl alcohol copolymer--tie layer whereby said laminate can be heat-sealed on conventional equipment at temperatures ranging from 250° F-500° F.   
     
     
       2. The container as claimed in claim 1 wherein said outer layer of low density polyethylene polymer is corona discharge treated to enhance printability of said laminate. 
     
     
       3. The container as claimed in claim 1 wherein said outer layer of low density polyethylene polymer is flame treated to enhance printability of said laminate. 
     
     
       4. The container as claimed in claim 1 wherein said tie layer is .[.a Plexar.]. .Iadd.an ethylene based copolymer with functional groups.Iaddend.. 
     
     
       5. A container for liquids containing essential oils and flavors, .Iadd.said container having an interior and an exterior, .Iaddend.said container constructed from a laminate comprising: (a) a paperboard substrate .Iadd.with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface.Iaddend.;   (b) a thin 0.8 mil thick outer layer of a heat-sealable low density polyethylene polymer .[.coated on.]. exterior to said outer surface of said paperboard substrate;   (c) .[.an inner.]. .Iadd.a coextruded .Iaddend.thin tie layer and a 0.2 to 0.7 mil thick layer of a heat-sealable ethylene vinyl alcohol copolymer, .[.coextruded on.]. .Iadd.interior to .Iaddend.said inner surface of said paperboard substrate, .Iadd.said heat-sealable ethylene vinyl alcohol copolymer layer being interior to said tie layer.Iaddend.; and   (d) a thin 0.7 mil thick .Iadd.product contact .Iaddend.layer of a heat-sealable low density polyethylene polymer .[.coated on an outer surface of.]. .Iadd.interior to .Iaddend.said .[.tie material-.]. ethylene vinyl alcohol copolymer layer whereby said laminate can be heat-sealed on conventional equipment at temperatures ranging from 250° F-500° F.   
     
     
       6. The container as claimed in claim 5 wherein said outer layer of low density polyethylene polymer is corona discharge treated to enhance printability of said laminate. 
     
     
       7. The container as claimed in claim 5 wherein said outer layer of low density polyethylene polymer is flame treated to enhance printability of said laminate. 
     
     
       8. The container as claimed in claim 6 wherein said surface of said inner layer of said heat-sealable ethylene vinyl alcohol copolymer is corona discharge treated to enhance adhesion of said thin heat-sealable LDPE layer. 
     
     
       9. The container as claimed in claim 7 wherein said surface of said inner layer of said heat-sealable ethylene vinyl alcohol copolymer is flame treated to enhance adhesion of said heat-sealable LDPE layer. 
     
     
       10. A container for liquids containing essential oils and flavors, .Iadd.said container having an interior and on exterior.Iaddend., constructed from a laminate comprising: (a) a paperboard substrate .Iadd.with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface.Iaddend.;   (.Iadd.b) .Iaddend.a thin 0.8 mil thick outer layer of a heat-sealable low density polyethylene polymer .[.coated on.]. .Iadd.exterior to .Iaddend.said outer surface of said paperboard substrate;   (c) an inner tie layer .[.of an ethylene acrylic acid coated on.]. .Iadd.interior to .Iaddend.said inner surface of said paperboard substrate;   (d) a 0.2 to 0.7 mil thick ethylene vinyl alcohol copolymer layer .[.coated on.]. .Iadd.interior to .Iaddend.said tie layer; and   (e) a thin 0.7 mil thick heat-sealable layer of low density polyethylene polymer .[.coated on.]. .Iadd.interior to .Iaddend.said .[.outer surface of said EVOH.]. .Iadd.ethylene vinyl alcohol copolymer layer whereby said laminate can be heat-sealed on conventional equipment at temperatures ranging from 250°  F- 500°  F.Iaddend..   
     
     
       11. The container as claimed in claim 10 wherein said outer layer of low density polyethylene polymer is corona discharge treated to enhance printability of said laminate. 
     
     
       12. The container as claimed in claim 10 wherein said outer layer of low density polyethylene polymer is flame treated to enhance printability of said laminate. 
     
     
       13. The container as claimed in claim 11 wherein said inner layer of ethylene vinyl alcohol copolymer is corona discharge treated to enhance adhesion of said subsequent heat-sealable LDPE coating. 
     
     
       14. The container as claimed in claim 12 wherein said inner layer of ethylene vinyl alcohol copolymer is flame treated to enhance adhesion of said subsequent heat-sealable LDPE coating. .Iadd.15. The container as claimed in claim 5 wherein said tie layer is an ethylene based copolymer 
     
     
        with functional groups. .Iaddend. .Iadd.16.  The container as claimed in claim 10 wherein said tie layer is an ethylene based copolymer with functional groups. .Iaddend. .Iadd.17. A container for liquids containinq essential oils and flavors, said container having an interior and an exterior, said container constructed from a laminate comprising: (a) a paperboard substrate with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface;   (b) a thin outer layer of a heat-sealable low density polyethylene polymer exterior to said outer surface of said paperboard substrate;   (c) a coextruded sandwich layer comprising a 4.5 lb. tie layer, a 4.0 lb. heat-sealable ethylene vinyl alcohol copolymer layer and a 4.5 lb. tie layer interior to said inner surface of said paperboard substrate; and   (d) a product-contact layer of a heat-sealable low density polyethylene poltmer interior to said outer surface of said inner sandwich layer of tie layer--ethylene vinyl alcohol copolymer--tie layer whereby said laminate can be heat-sealed on conventional equipment at temperatures ranging from 250°  F- 500°  F. .Iaddend. .Iadd.18. The container as claimed in claim 17 wherein said outer layer of low density polyethylene polymer is corona discharge treated to enhance printability of said   
     
     
        laminate. .Iaddend. .Iadd.19.  The container as claimed in claim 17 wherein said outer layer of low density polyethylene polymer is flame treated to enhance printability of said laminate. .Iaddend. .Iadd.20. The container as claimed in claim 17 wherein said tie layer is an ethylene based copolymer with functional groups. .Iaddend. .Iadd.21. A container for liquids containing essential oils and flavors, said container having an interior and an exterior, said container constructed from a laminate comprising: (a) a paperboard substrate with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface;   (b) a thin outer layer of a heat-sealable low density polyethylene polymer exterior to said outer surface of said paperboard substrate,   (c) a coextruded thin tie layer and a 0.2 to 0.7 mil thick layer of a heat-sealable ethylene vinyl alcohol copolymer, interior to said inner surface of said paperboard substrate, said heat-sealable ethylene vinyl alcohol copolymer layer being interior to said tie layer; and   (d) a thin product contact layer of a heat-sealable low density polyethylene polymer interior to said ethylene vinyl alcohol copolymer layer whereby said laminate can be heat-sealable on conventional equipment at temperatures ranging from 250°  F- 500°  F. .Iaddend.   
     
     
        .Iadd.22.  The container as claimed in claim 21 wherein said outer layer of low density polyethylene polymer is corona discharge treated to enhance printability of said laminate. .Iaddend. .Iadd.23. The container as claimed in claim 21 wherein said outer layer of low density polyethylene polymer is flame treated to enhance printability of said laminate. .Iaddend. .Iadd.24. The container as claimed in claim 22 wherein said surface of said inner layer of said heat-sealable ethylene vinyl alcohol copolymer is corona discharge treated to enhance adhesion of said thin heat-sealable LDPE layer. .Iaddend. .Iadd.25. The container as claimed in claim 23 wherein said surface of said inner layer of said heat-sealable ethylene vinyl alcohol copolymer is flame treated to enhance adhesion of said heat-sealable LDPE layer. .Iaddend. .Iadd.26. The container as claimed in claim 21 wherein said tie layer is an ethylene based copolymer with functional groups. .Iaddend. .Iadd.27. A container for liquids containing essential oils and flavors, said container having an interior and on exterior, constructed from a laminate comprising: (a) a paperboard substrate with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface;   (b) a thin outer layer of a heat-sealable low density polyethylene polymer exterior to said outer surface of said paperboard substrate:   (c) an inner tie layer interior to said inner surface of said paperboard substrate:   (d) a 0.2 to 0.7 mil thick ethylene vinyl alcohol copolymer layer interior to said tie layer: and   (e) a thin heat-sealable layer of low density polyethylene polymer interior to said ethylene vinyl alcohol copolymer layer whereby said laminate can be heat-sealable on conventional equipment at temperatures ranging from   
     
     
        250°  F- 500°  F. .Iaddend. .Iadd.28.  The container as claimed in claim 27 wherein said outer layer of low density polyethylene polymer is corona discharge treated to enhance printability of said aminate. .Iaddend. .Iadd.29. The container as claimed in claim 27 wherein said outer layer of low density polyethylene polymer is flame treated to enhance printability of said laminate. .Iaddend. .Iadd.30. The container as claimed in claim 28 wherein said inner layer of ethylene vinyl alcohol copolymer is corona discharge treated to enhance adhesion of said subsequent heat-sealable LDPE coating. .Iaddend. .Iadd.31. The container as claimed in claim 29 wherein said inner layer of ethylene vinyl alcohol copolymer is flame treated to enhance adhesion of said subsequent heat-sealable LDPE coating. .Iaddend. .Iadd.32. The container as claimed in claim 27 wherein said tie layer is an ethylene based copolymer with 
     
     
        functional groups. .Iaddend. .Iadd.33.  A container for liquids containing essential oils and flavors, said container having an interior and an exterior, said container constructed from a laminate comprising: (a) a paperboard substrate with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface;   (b) a thin outer layer of a heat-sealable, low density polyethylene polymer exterior to said outer surface of said paperboard substrate;   (c) a 0.2 to 0.7 mil thick ethylene vinyl alcohol copolymer layer interior to said inner surface of said paperboard substrate; and   (d) a thin heat-sealable layer of low density polyethylene polymer interior to said ethylene vinyl alcohol copolymer layer whereby said laminate can be heat-sealed on conventional equipment at temperatures ranging from 250°  F.- 500°  F. .Iaddend. .Iadd.34. The container as claimed in claim 33 wherein said outer layer of low density polyethylene polymer is corona discharged treated to enhance printability of said   
     
     
        laminate. .Iaddend. .Iadd.35.  The container as claimed in claim 33 wherein said outer layer of low density polyethylene polymer is flame treated to enhance printability of said laminate. .Iaddend. .Iadd.36. The container as claimed in claim 34 wherein said inner layer of ethylene vinyl alcohol copolymer is corona discharged treated to enhance adhesion of said subsequent heat-sealable low density polyethylene polymer coating. .Iaddend. .Iadd.37. The container as claimed in claim 35 wherein said inner layer of ethylene vinyl alcohol copolymer is flame treated to enhance adhesion of said subsequent heat-sealable low density polyethylene polymer coating. .Iaddend. .Iadd.38. A container for liquids containing essential oils and flavors, said container from a laminate comprising: (a) a paperboard substrate with inner and outer surfaces, said inner surface being closer to the interior of the container than said outer surface;   (b) a thin 0.8 mil thick outer layer of a heat-sealable low density polyethylene polymer exterior to said outer surface of said paperboard substrate;   (c) a 0.2 to 0.7 thick ethylene vinyl alcohol copolymer layer interior to said inner surface of said paperboard substrate; and   (d) a thin 0.7 mil thick heat-sealable layer of low density polyethylene polymer interior to said ethylene vinyl alcohol copolymer layer whereby said laminate can be heat-sealed on conventional equipment at temperatures ranging from 250°  F.- 500°  F. .Iaddend. .Iadd.39. The container as claimed in claim 38 wherein said outer layer of low density polyethylene polymer is corona discharged treated to enhance printability of said laminate. .Iaddend. .Iadd.40. The container as claimed in claim 38 wherein said outer layer of low density polyethylene polymer is flame   
     
     
        treated to enhance printability of said laminate. .Iaddend. .Iadd.41.  The container as claimed in claim 39 wherein said inner layer of ethylene vinyl alcohol copolymer is corona discharged treated to enhance adhesion of said subsequent heat-sealable low density polyethylene polymer coating. .Iaddend. .Iadd.42. The container as claimed in claim 40 wherein said inner layer of ethylene vinyl alcohol copolymer is flame treated to enhance adhesion of said subsequent heat-sealable low density polyethylene polymer coating. .Iaddend.