Oriented Film Produced In-Process for Use in the Power Stretch Film Market
The present disclosure describes compositions, devices, systems, and methods for producing films which simplify the application process by eliminating the need to stretch film before it is wrapped around a load. Such films also provide enhanced load containment and increased resistance to punctures and breaks. In particular, the present disclosure relates to the use of selected resins and an angled die to increase the level of orientation in the film as it is formed.
1 . An oriented film produced in-process, the oriented film having a majority component and a minority component, as measured in percent of total film thickness, wherein:
the majority component is comprised of a linear low density polyethylene (LLDPE) copolymer; and
the minority component is comprised of resins chosen from the group consisting of polyethylenes, polyethylene copolymers, metallocene catalyzed polypropylenes, polypropylenes, and polypropylene copolymers.
2 . The oriented film according to claim 1 , wherein the minority component has a thickness ranging from 8 to 30 percent of the total film thickness.
3 . The oriented film according to claim 2 , wherein the minority component has a thickness of approximately 16 percent of the total film thickness.
4 . The oriented film according to claim 1 , wherein the resins comprising the minority component have a melt index ranging from 0.5 to 12 (g/10 min. @190° C./2.16 kg).
5 . The oriented film according to claim 4 , wherein the resins comprising the minority component have a melt index ranging from 3 to 5 (g/10 min. @190° C./2.16 kg).
6 . The oriented film according to claim 1 , wherein the resins comprising the minority component have a density ranging from 0.850 g/cm 3 to 0.960 g/cm 3 .
7 . The oriented film according to claim 6 , wherein the resins comprising the minority component have a density of approximately 0.917 g/cm 3 .
8 . The oriented film according to claim 1 , wherein the majority component is comprised of a higher alpha-olefin LLDPE.
9 . The oriented film according to claim 1 , wherein the LLDPE comprising the majority component has a melt index ranging from 0.5 to 4 (g/10 min. @190° C./2.16 kg).
10 . The oriented film according to claim 9 , wherein the LLDPE comprising the majority component has a melt index ranging from 0.6 to 1.2 (g/10 min. @190° C./2.16 kg).
11 . The oriented film according to claim 1 , wherein the LLDPE comprising the majority component has a density ranging from 0.900 g/cm 3 to 0.960 g/cm 3 .
12 . The oriented film according to claim 11 , wherein the LLDPE comprising the majority component has a density ranging from 0.910 g/cm 3 to 0.935 g/cm 3 .
13 . The oriented film according to claim 11 , wherein the LLDPE comprising the majority component has a density of approximately 0.920 g/cm 3 .
14 . An apparatus for producing oriented film, the apparatus comprising:
an extruder that receives a resin and melts the resin to a selected temperature that allows the resin to melt; and
an angled die that delivers a layer of melted resin from the extruder onto a casting roll to produce a film.
15 . The apparatus according to claim 14 , wherein the die is angled to an intercept angle that is less than 90°.