MULTI-PLY FILMS FOR STERILIZATION OR PASTEURIZATION PROCESSES
Multi-ply films are provided that include a top layer affixed to a coextruded film. The coextruded film includes at least a first polyamide structural layer, a sealant layer, and a first tie layer that is disposed between the first polyamide structural layer and the sealant layer, in which the coextruded film is substantially free of an adhesive. Packages that include the multi-ply films and methods for sterilization are also provided.
1 . A multi-ply film comprising a top layer that is affixed to a coextruded film by an adhesive layer disposed between the top layer and the coextruded film, wherein:
the coextruded film comprises a first polyamide structural layer, a sealant layer, and a first tie layer disposed between the first polyamide structural layer and the sealant layer; and
the coextruded film is substantially free of an adhesive,
wherein the first polyamide structural layer is a biaxially unoriented nylon.
2 . The multi-ply film of claim 1 , wherein the coextruded film further comprises an outer layer, in which the first polyamide structural layer is disposed between the sealant layer and the outer layer, and a second tie layer disposed between the first polyamide structural layer and the outer layer.
3 . The multi-ply film of claim 2 , wherein the coextruded film further comprises a second polyamide structural layer, in which the second polyamide structural layer is disposed between the second tie layer and the outer layer, and a third tie layer disposed between the second polyamide structural layer and the outer layer.
4 . The multi-ply film of claim 1 , wherein the first polyamide structural layer comprises adjacent layers of biaxially unoriented nylon or the second polyamide structural layer comprises a nylon.
5 . (canceled)
6 . The multi-ply film of claim 1 , wherein the coextruded film further comprises an inner layer comprising a polypropylene, a polyethylene, or combination thereof disposed between the sealant layer and the first tie layer.
7 . (canceled)
8 . The multi-ply film of claim 1 , wherein the sealant layer comprises a blend of an easy-peel component and a polypropylene.
9 . The multi-ply film of claim 8 , wherein the easy-peel component is present in the sealant layer of the coextruded film in an amount from about 16 to about 28% by weight of the sealant layer and the polypropylene is present in the sealant layer of the coextruded film in an amount from about 72 to about 84% by weight of the sealant layer and the easy-peel component comprises a heat-sealable blend of a polypropylene, a polyethylene, an antiblock agent, and a slip agent.
10 . (canceled)
11 . The multi-ply film of claim 9 , wherein the antiblock agent comprises diatomaceous earth.
12 . The multi-ply film of claim 9 , wherein the slip agent comprises erucamide.
13 . The multi-ply film of claim 2 , wherein the outer layer of the coextruded film comprises a polypropylene or a blend of apolypropylene and a polyethylene.
14 . The multi-ply film of claim 1 , wherein the top layer comprises an oriented polyester, an oriented polyamide, or a combination thereof.
15 . The multi-ply film of claim 14 , wherein the top layer further comprises a high barrier coating.
16 . (canceled)
17 . The multi-ply film of claim 13 , wherein the polypropylene is present in the outer layer of the coextruded film in an amount from about 90 to about 100% by weight of the outer layer.
18 . (canceled)
19 . The multi-ply film of claim 1 , wherein the multi-ply film comprises a two-ply film and wherein the multi-ply film has an improved ratio of peel strength:burst strength as compared to a three-ply film comprising the top layer, a biaxially-oriented nylon layer, and a sealant layer affixed together by adhesive layers.
20 . (canceled)
21 . The multi-ply film of claim 1 , wherein the multi-ply film comprises a three-ply film and further comprises a foil layer.
22 . (canceled)
23 . A package comprising the multi-ply film of claim 1 .
24 .- 25 . (canceled)
26 . The package of claim 23 , wherein the package comprises a pouch formed from the multi-ply film.
27 . (canceled)
28 . The package of claim 23 , wherein the package comprises a rigid or semi-rigid container having a rim for affixing the multi-ply film thereto.
29 . (canceled)
30 . The package of claim 23 , wherein the first polyamide structural layer comprises adjacent layers of biaxially unoriented nylon.
31 . The package of claim 30 , wherein the coextruded film further comprises an inner layer disposed between the sealant layer and the first tie layer.
32 . A method for sterilization, the method comprising:
feeding the package of claim 23 into a sterilizing chamber, wherein the package has product disposed therein; and
preserving the product within the sterilizing chamber by thermal sterilization.
33 . The method of claim 32 , wherein the thermal sterilization is retort sterilization, microwave assisted thermal sterilization, or ultra-high temperature sterilization.
34 .- 37 . (canceled)
38 . A roll of film for forming a package, said roll of film comprising the multi-ply film in claim 1 .
39 .- 42 . (canceled)
43 . The multi-ply film of claim 2 , wherein the first tie layer, the second tie layer, or both comprise anhydride modified polypropylene, modified ethylene vinyl acetate, anhydride modified ethylene acrylate, acid/acrylate modified ethylene vinyl acetate, anhydride modified ethylene vinyl acetate, and combinations thereof.
44 . (canceled)
45 . A method of making a multi-ply film comprising
affixing a top layer to a coextruded film by an adhesive layer disposed between the top layer and the coextruded film, wherein:
the coextruded film comprises a first polyamide structural layer, a sealant layer, and a first tie layer disposed between the first polyamide structural layer and the sealant layer; and
the coextruded film is substantially free of an adhesive,
wherein the first polyamide structural layer is a biaxially unoriented nylon.
46 .- 66 . (canceled)