CAST POWER STRETCH FILMS WITH IMPROVED LOAD CONTAINMENT FORCE
The present disclosure generally relates to compositions and methods for incorporating higher density metallocene linear low density polyethylene (m-LLDPE) into cast power stretch films. When compared to conventional machine films on a gauge-by-gauge basis, films containing the properly selected m-LLDPE may offer increased load containment force, reduced application force, and comparable elongation and puncture resistance properties.
1 . A cast power stretch film comprised of a higher density m-LLDPE, the cast power stretch film having a total film thickness.
2 . The cast power stretch film according to claim 1 , wherein the higher density m-LLDPE is blended with resins chosen from the group consisting of polyethylenes, polyethylene copolymers, polypropylenes, and polypropylene copolymers.
3 . The cast power stretch film according to claim 1 , wherein the film is comprised of a plurality of discrete layers.
4 . The cast power stretch film according to claim 3 , wherein a discrete layer of the film is comprised of the higher density m-LLDPE.
5 . The cast power stretch film according to claim 4 , wherein the discrete layer of the film that is comprised of the higher density m-LLDPE has a thickness ranging from 5 to 70 percent of the total film thickness.
6 . The cast power stretch film according to claim 5 , wherein the discrete layer of the film that is comprised of the higher density m-LLDPE has a thickness of approximately 32 percent of the total film thickness.
7 . The cast power stretch film according to claim 1 , wherein the higher density m-LLDPE has a melt index ranging from 0.5 to 8.0 (g/10 min. @190° C./2.16 kg).
8 . The cast power stretch film according to claim 7 , wherein the higher density m-LLDPE has a melt index ranging from 1.0 to 3.0 (g/10 min. @190° C./2.16 kg).
9 . The cast power stretch film according to claim 7 , wherein the higher density m-LLDPE has a melt index of approximately 2.0 (g/10 min. @ 190° C./2.16 kg).
10 . The cast power stretch film according to claim 1 , wherein the higher density m-LLDPE has a density ranging from 0.900 g/cm 3 to 0.960 g/cm 3 .
11 . The cast power stretch film according to claim 10 , wherein the higher density m-LLDPE has a density ranging from 0.922 g/cm 3 to 0.940 g/cm 3 .
12 . The cast power stretch film according to claim 10 , wherein the higher density m-LLDPE has a density of approximately 0.925 g/cm 3 .
13 . The cast power stretch film according to claim 1 , wherein the higher density m-LLDPE is comprised of a higher alpha-olefin comonomer.
14 . A cast power stretch film comprised of five layers, the film having a total film thickness, wherein a discrete layer is comprised of a higher density m-LLDPE.
15 . The cast power stretch film according to claim 14 , wherein the higher density m-LLDPE is blended with resins chosen from the group consisting of polyethylenes, polyethylene copolymers, polypropylenes, and polypropylene copolymers.
16 . The cast power stretch film according to claim 14 , wherein the discrete layer has a thickness ranging from 5 to 70 percent of the total film thickness.
17 . The cast power stretch film according to claim 16 , wherein the discrete layer has a thickness of approximately 32 percent of the total film thickness.
18 . The cast power stretch film according to claim 14 , wherein the higher density m-LLDPE has a melt index ranging from 0.5 to 8.0 (g/10 min. @190° C./2.16 kg).
19 . The cast power stretch film according to claim 18 , wherein the higher density m-LLDPE has a melt index ranging from 1.0 to 3.0 (g/10 min. @190° C./2.16 kg).
20 . The cast power stretch film according to claim 18 , wherein the higher density m-LLDPE has a melt index of approximately 2.0 (g/10 min. @ 190° C./2.16 kg).
21 . The cast power stretch film according to claim 14 , wherein the higher density m-LLDPE has a density ranging from 0.900 g/cm 3 to 0.960 g/cm 3 .
22 . The cast power stretch film according to claim 21 , wherein the higher density m-LLDPE has a density ranging from 0.922 g/cm 3 to 0.940 g/cm 3 .
23 . The cast power stretch film according to claim 21 , wherein the higher density m-LLDPE has a density of approximately 0.925 g/cm 3 .
24 . The cast power stretch film according to claim 14 , wherein the higher density m-LLDPE is comprised of a higher alpha-olefin comonomer.
25 . The cast power stretch film according to claim 14 , wherein the film is comprised of:
a layer comprised of ZN-catalyzed LLDPE, with a thickness of approximately 10 percent of the total film thickness;
a layer comprised of conventional m-LLDPE, with a thickness of approximately 32 percent of the total film thickness;
a layer comprised of ZN-catalyzed LLDPE, with a thickness of approximately 16 percent of the total film thickness;
a layer comprised of higher density m-LLDPE, with a thickness of approximately 32 percent of the total film thickness; and
a layer comprised of ZN-catalyzed LLDPE, with a thickness of approximately 10 percent of the total film thickness.