Recyclable flexible films and bags for packaging flowable materials
The disclosure provides ethylene/α-olefin copolymer based co-extruded, multi-layer films, including barrier films and non-barrier films, and articles of manufacture that include the films, such as flexible bags and containers for flowable materials. The films and articles that include the films have improved flex-crak reisstance and toughness. The films and articles that include the films have good barrier properties as the barrier films include a core layer of ethylene-vinyl alcohol (EVOH) copolymer having a high ethylene content. The low amount of EVOH copolymer in the total film that is needed to achieve the flex-crack resistance, toughness, and good barrier properties, further allow for the recycling of the films and articles of manufacture.
1. A co-extruded multi-layer polymeric recyclable barrier film, comprising:
(i) an inner sealant layer comprising an ethylene/α-olefin copolymer fraction having a density in the range of 0.894 to 0.920 g/cm 3 in an amount of at least about 50% by weight or thickness of the total inner sealant layer, wherein the inner sealant layer has a total density in the range of from about 0.910 to 0.924 g/cm3;
(ii) a core barrier layer comprising ethylene-vinyl alcohol (EVOH) copolymer comprising about 0.1% to about 10% by total weight or thickness of the co-extruded multi-layer polymeric recyclable barrier film, wherein the EVOH comprises at least 38% ethylene in the EVOH copolymer; and
(iii) an outer sealant layer comprising an ethylene/a-olefin copolymer fraction having a density in the range of 0.894 to 0.920 g/cm3 in an amount of at least about 50% by weight or thickness of the total outer sealant layer, wherein the outer sealant layer has a total density in the range of from about 0.910 to 0.924 g/cm3.
2. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , wherein the ethylene/α-olefin interpolymer in at least one of the inner sealant layer and the outer sealant layer comprises at least one metallocene linear low density polyethylene (mLLDPE) having a density of 0.912 g/cm 3 .
3. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , wherein the percent weight or thickness of the EVOH layer relative to the entire film is selected from the following numbers: 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, and 5.0.
4. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , wherein the ethylene/a-olefin interpolymer in at least one of the inner sealant layer and the outer sealant layer has a melt index in the range of 0.2 to 2.0 dg/min.
5. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , wherein the ethylene/α-olefin interpolymer in at least one of the inner sealant layer and the outer sealant layer has a zero shear viscosity ratio (ZSVR) in the range of 1.15 to 2.5.
6. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , wherein the ethylene/α-olefin interpolymer in at least one of the inner sealant layer and the outer sealant layer has a molecular weight distribution, expressed as the ratio of the weight average molecular weight to number average molecular weight (Mw/Mn), in the range of 2.0-4.0.
7. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , wherein the total thickness the film is from about 1 mil to about 5 mils.
8. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , further comprising at least a first and a second interposed layer,
each of the first and second interposed layer comprising an ethylene/α-olefin copolymer fraction having a density in the range of 0.894 to 0.920 g/cm3 in an amount of at least about 50% by weight or thickness of the interposed layer and an adhesive or tie resin in an amount effective to improve adhesion of the interposed layer to at least one other layer in the co-extruded multi-layer polymeric film, and
each of the first and second interposed layers has a total density in the range of from about 0.910 to 0.924 g/cm3.
9. The co-extruded multi-layer polymeric recyclable barrier film of claim 1 , wherein the ethylene/α-olefin interpolymer in at least one of the inner sealant layer and the outer sealant layer comprises a polymer fraction of linear low density polyethylene and a second copolymer fraction of an ethylene/octene-1 copolymer, an ethylene/hexene-1 copolymer, or an ethylene/butene-1 copolymer.
10. The co-extruded multi-layer polymeric recyclable barrier film of claim 9 , wherein the interpolymer has a density of 0.915 g/cm 3 and a melt index of 0.80-1.0 dg/min.
11. A recyclable bag for packaging flowable materials comprising the co-extruded multi-layer polymeric recyclable barrier film of claim 1 .
12. The recyclable bag of claim 11 , further comprising a non-barrier co-extruded multi-layer polymeric film, wherein the co-extruded multi-layer polymeric recyclable barrier film is a first ply of a two-ply structure and the non-barrier co-extruded multi-layer polymeric film is a second ply of the two-ply structure.
13. The recyclable bag of claim 12 , wherein the thickness of each of the co-extruded multi-layer polymeric recyclable barrier film and the non-barrier co-extruded multi-layer polymeric film is from about 1 mil to about 5 mils.
14. The recyclable bag of claim 12 , wherein a ratio between a thickness of the non-barrier co-extruded multi-layer polymeric film and a thickness of the co-extruded multi-layer polymeric recyclable barrier film is between 1.1:1 and 3:1.
15. The recyclable bag of claim 12 , wherein the co-extruded multi-layer polymeric recyclable barrier film is an outer ply and the non-barrier co-extruded multi-layer polymeric film is an inner ply.
16. The recyclable bag of claim 12 , wherein the bag comprises a first wall and a second wall, the first and second walls being sealed along perimeter edges to define an interior volume for containing a flowable material, and a dispensing spout or fitment sealed to one of the first and second walls.
17. The recyclable bag of claim 16 , further comprising a flowable material within the interior of the bag.
18. The recyclable bag of claim 17 , wherein the recyclable bag is configured to empty from about 95% to about 99.9% of the flowable material without incorporating any evacuation aid device.
19. The recyclable bag of claim 17 , wherein the flowable material is concentrated soft drink syrup.
20. A bag-in-box container comprising the recyclable bag of claim 17 .