PACKAGING FILM WITH SUPERIOR SEAL, BARRIER, AND FLEX CRACK RESISTANCE
A packaging film having enhanced barrier properties, sealability, and flex-crack resistance characteristics and is ideal for use in packaging of food products, such as chunk cheese, to increase shelf life thereof.
1 . A packaging film comprising:
a barrier layer having a first surface and a second surface opposite the first surface, said barrier layer comprising a coextruded multilayer structure having an oxygen barrier core layer effective to limit passage of oxygen through the packaging film;
an abuse layer disposed on the first surface of the barrier layer, said abuse layer effective to resist flex cracking of the packaging film; and
a sealant layer disposed on the second surface of the barrier layer, the sealant layer configured to provide a hermetic seal upon being heat sealed with a like sealant layer of an aligned packaging film.
2 . The packaging film of claim 1 , wherein the barrier layer comprises:
a first intermediate layer on a first side of the oxygen barrier core layer and a second intermediate layer on a second side of the core layer opposite the first side of a middle barrier layer; and
a first outer layer disposed on the first intermediate layer and a second outer layer disposed on the second intermediate layer.
3 . The packaging film of claim 2 , wherein the first and second intermediate layers contain a first material and the first and second outer layers contain a second material.
4 . The packaging film of claim 3 , wherein the first material is a tie resin and the second material is a polyolefin or polyolefin copolymer.
5 . The packaging film of claim 4 , wherein the second material is selected from polyethylene or ethylene vinyl acetate.
6 . The packaging film of claim 5 , wherein the polyethylene density is between 0.9 to 0.94 g/cm 3 .
7 . The packaging film of claim 1 , wherein the barrier layer has a thickness of 0.8 mil to 2 mil.
8 . The packaging film of claim 1 , wherein the oxygen barrier core layer contains ethylene vinyl alcohol.
9 . The packaging film of claim 1 , wherein the abuse layer contains biaxially oriented nylon.
10 . The packaging film of claim 1 , further comprising:
an adhesive layer disposed between the abuse layer and the barrier layer.
11 . The packaging film of claim 10 , wherein the adhesive layer is selected from polyethylene and polyurethane.
12 . The packaging film of claim 1 , wherein the sealant layer is a low seal initiation temperature ethylene copolymer.
13 . The packaging film of claim 12 , wherein the sealant layer is a low seal initiation temperature ethylene copolymer having a comonomer content of about 12% or higher and a melt flow index of about 20 g/in or higher.
14 . The packaging film of claim 12 , wherein the sealant layer is an ethylene vinyl acetate (EVA).
15 . A method of manufacturing an oxygen barrier packaging film comprising the steps of:
coextruding a multilayer barrier structure having a first surface and a second surface opposite the first surface, said multilayer barrier layer comprising an oxygen barrier core layer;
attaching an abuse layer to the first surface of the multilayer barrier structure; and
forming a sealant layer on the second surface.
16 . The method of claim 15 , wherein the abuse layer is attached to the first surface using an adhesive.
17 . The method of claim 15 , wherein sealant layer is formed on the second surface using an extrusion coating process.
18 . The method of claim 15 , wherein the multilayer barrier structure includes:
a first intermediate layer on a first side of the oxygen barrier core layer and a second intermediate layer on a second side of the core layer opposite the first side of a middle barrier layer; and
a first outer layer disposed on the first intermediate layer and a second outer layer disposed on the second intermediate layer.
19 . The method of claim 18 , wherein each of the first and second intermediate layers is a tie resin and each of the first and second outer layers is selected from the group consisting of polyethylene and polyethylene copolymers.
20 . The method of claim 15 , wherein the oxygen barrier core layer contains ethylene vinyl alcohol.
21 . The method of claim 15 , wherein the abuse layer contains biaxially oriented nylon.
22 . The method of claim 15 , wherein the sealant layer is a low seal initiation temperature ethylene copolymer.
23 . A food package, comprising:
opposing front and back panels of a polymer packaging film;
a barrier layer of the polymer packaging film having a first surface and a second surface opposite the first surface, said barrier layer comprising a coextruded multilayer structure having an oxygen barrier core layer effective to limit the passage of oxygen through the packaging film;
an abuse layer of the packaging film disposed on the first surface of the barrier layer, said abuse layer effective to resist flex cracking of the packaging film;
a sealant layer of the packaging film disposed on the second surface of the barrier layer, the sealant layer configured to provide a hermetic seal upon being heat sealed with a like sealant layer of an aligned packaging film; and
a hermetic seal between at least a portion of the front and back panels of the polymer packaging film.