Forming web for lining a rigid container

• US 5,183,706 A
• Filed: 08/03/1990
• Issued: 02/02/1993
• Est. Priority Date: 08/03/1990
• Status: Expired due to Term

• Current Assignee: Cryovac Incorporated (Sealed Air)
• Original Assignee: W R Grace & Company - CONN (Standard Industries Holdings, Inc.)
• Inventors: Bekele, Solomon
• Primary Examiner(s): Buffalow, Edith
• Application Number:
  US07/562,537
• Time in Patent Office: 914 Days
• Field of Search: 428/349, 428/474.7, 428/474.9, 428/475.8, 428/476.1, 428/520, 428/35.4, 428/34.2, 428/500, 156/244.11
• US Class Current: 428/349
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: B32B 2307/31 Heat sealable
• CPC Class Codes: B32B 2307/7244 Oxygen barrier
• CPC Class Codes: B32B 2439/00 Containers; Receptacles
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 37/08 characterised by the cooling method
• CPC Class Codes: B32B 37/153 at least one layer is extruded and immediately laminated while in semi-molten state
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: B65D 5/563 Laminated linings; Coatings
• CPC Class Codes: Y10T 428/1303 Paper containing [e.g., paperboard, cardboard, fiberboard, etc.]
• CPC Class Codes: Y10T 428/1341 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/2826 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/31728 Next to second layer of polyamide
• CPC Class Codes: Y10T 428/31732 At least one layer is nylon type
• CPC Class Codes: Y10T 428/31743 Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/31746 Polymer of monoethylenically unsaturated hydrocarbon
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31928 Ester, halide or nitrile of addition polymer

Abstract

A forming web suitable for lining the interior of a rigid or simirigid container, such as a box made from corrugated board, includes an outer sealable layer; an interior barrier layer comprising a polymeric material with low oxygen transmission; a polymeric layer which adds bulk to the web; and an inner adherent layer. The web can also include polymeric adhesive layers for bonding the outer sealable layer to the interior layer, and the bulk layer to the interior and inner adherent layers respectively. More than one bulk or barrier can be included in the present invention.

Claims

1. A forming web comprising:

a) an outer sealably layer;

b) an interior barrier layer comprising a polymeric material with low oxygen transmission;

c) a polymeric layer which adds bulk to the web, said polymeric material selected from the group, consisting of polystyrene polymer and copolymer; and

d) an innermost adherent layer comprising a polymeric material selected from the group consisting of ethylene acrylic acid copolymer, ethylene methacrylic acid copolymer, tackified ethylene vinyl acetate copolymer, chemically modified ethylene ethyl acrylate copolymer, chemically modified ethylene methyl acrylate copolymer, chemically modified ethylene vinyl acetate copolymer, chemically modified linear low density polyethylene, chemically modified high density polyethylene, chemically modified low density polyethylene, and chemically modified polypropylene;

said adherent layer capable of bonding to a paperboard or other container, or to other thermoplastic materials.

2. The web of claim 1 wherein the outer sealable layer is a heat sealable polymeric material selected from the group consisting of:

a) low density polyethylene;

b) linear low density polyethylene;

c) very low density polyethylene;

d) ethylene vinyl acetate copolymer;

e) ethylene alkyl acrylate copolymer;

f) ethylene acrylic acid copolymer;

g) ethylene methacrylic acid copolymer;

h) ionomer; and

i) blends of these materials.

3. The web of claim 2 wherein the ethylene alkyl acrylate copolymer is selected from the group consisting of:

a) ethylene n-butyl acrylate copolymer;

b) ethylene ethyl acrylate copolymer; and

c) ethylene methyl acrylate copolymer.

4. The web of claim 1 wherein the interior barrier layer comprises a polymeric material with low oxygen transmission selected from the group consisting of:

a) ethylene vinyl alcohol copolymer;

b) polyamide;

c) copolyamide; and

d) blends of these materials.

5. The web of claim 4 wherein the polyamide is selected from the group consisting of:

a) amorphous nylon;

b) nylon 6;

c) nylon 11;

d) nylon 12; and

e) nylon 610.

6. The web of claim 4 wherein the copolyamide is selected from the group consisting of:

a) amorphous nylon;

b) nylon 6,12;

c) nylon 6,66; and

d) nylon 6,69.

7. The web of claim 1 wherein the bulk layer comprises a:

high impact polystyrene.

8. The web of claim 7 wherein the styrene copolymer is selected from the group consisting of:

a) styrene acrylonitrile copolymer;

b) styrene methyl methacrylate copolymer;

c) acrylonitrile butadiene styrene;

d) styrene butadiene copolymer;

e) styrene maleic anhydride copolymer; and

f) styrene alkyl styrene copolymer.

9. The web of claim 1 wherein the chemically modified olefin polymer or copolymer of the innermost adherent layer is selected from the group consisting of:

a) chemically modified ethylene ethyl acrylate copolymer;

b) chemically modified ethylene methyl acrylate copolymer;

c) chemically modified ethylene vinyl acetate copolymer;

d) chemically modified linear low density polyethylene;

e) chemically modified high density polyethylene;

f) chemically modified low density polymethylene; and

g) chemically modified polypropylene.

10. The web of claim 1 further comprising a polymeric adhesive layer disposed between the outer sealable layer and the interior barrier layer.

11. The web of claim 10 wherein the polymeric adhesive comprises a material selected from the group consisting of:

a) low density polyethylene;

b) linear low density polyethylene;

c) very low density polyethylene;

d) ethylene vinyl acetate copolymer;

e) ethylene methyl acrylate copolymer; and

f) polypropylene;

wherein the material is chemically modified to enhance its adhesive properties.

12. The web of claim 1 further comprising a polymeric adhesive layer disposed between the interior barrier layer and the bulk layer, and between the bulk layer and the innermost adherent layer.

13. The web of claim 12 wherein the polymeric adhesive layer comprises a material selected from the group consisting of:

a) ethylene vinyl acetate copolymer; and

b) ethylene methyl acrylate copolymer;

wherein the material is chemically modified to enhance its adhesive properties.

14. The web of claim 1 wherein the web is cross-linked.

15. The web of claim 14 wherein the web is cross-linked by irradiation.

16. A method of making a forming web comprising:

a) coextruding an outer sealable layer, an interior layer of a polymeric material with low oxygen transmission, a bulk layer of a polymeric material selected from the group consisting of polystyrene, polymer and copolymer, and an inner adherent layer, and adhesive layers disposed between the outer sealable layer and the interior layer, between the interior layer and the bulk layer, and between the bulk layer and the inner adherent layer;

b) cooling the coextruded web; and

c) winding up the cooled web.

17. The method of claim 16 wherein the web is cross-linked.

18. The method of claim 16 wherein the web is cross-linked by irradiation.