Blends of medium density polyethylene with other polyolefins
AssigneeFina Technology, Inc.
InventorsRodolfo Mier, John Sczesny
Life of this patent
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Abstract
It has been discovered that the properties of sheet or film materials of medium density polyethylene made using a metallocene catalyst (mMDPE) can be improved by blending the mMDPE with a second polyolefin. The second poly-olefin may be a low density polyethylene (LDPE) or a second, different medium density polyethylene (2dMDPE). Improvements include, but are not necessarily limited to, reduced motor amps, a reduction in sealing temperature, and an increase in machine direction tear resistance as compared with an identical material absent the second polyolefin. These sheet or film materials may be co-extruded with other resins or laminated with other materials after extrusion.
Claims30
A film or sheet material comprising a blend of:
- at least one medium density polyethylene made using a metallocene catalyst (mMDPE) and
- from about 10 to about 90 wt % of at least one second polyolefin, where the second polyolefin is selected from the group consisting of
- a low density polyethylene (LDPE), and
- a second medium density polyethylene (2dMDPE).
A copolymer resin blend comprising:
- at least one medium density polyethylene made using a metallocene catalyst (mMDPE) and
- from about 10 to about 90 wt % of at least one second polyolefin, where the second polyolefin is selected from the group consisting of
- a low density polyethylene (LDPE), and
- a second medium density polyethylene (2dMDPE).
A process for making a blown film comprising:
- blending at least one medium density polyethylene made using a metallocene catalyst (mMDPE) with from about 10 to about 90 wt % of at least one second polyolefin, where the second polyolefin is selected from the group consisting of a low density polyethylene (LDPE), and a second medium density polyethylene (2dMDPE);
- feeding the polymer blend to an extruder;
- extruding the polymer blend through an annular die to form a molten tube;
- and
- blowing the tube into a bubble using air to form a blown film structure.
A process for making a multilayer film or sheet material comprising co-extruding at least two resins together where one of the resins is a resin blend comprising:
- at least one medium density polyethylene made using a metallocene catalyst (mMDPE) and
- from about 10 to about 90 wt % of at least one second polyolefin, where the second polyolefin is selected from the group consisting of
- a low density polyethylene (LDPE), and
- a second medium density polyethylene (2dMDPE).
A process for making a laminated article having at least two layers comprising:
- blending at least one medium density polyethylene made using a metallocene catalyst (mMDPE) with from about 10 to about 90 wt % of at least one second polyolefin, where the second polyolefin is selected from the group consisting of a low density polyethylene (LDPE), and a second medium density polyethylene (2dMDPE);
- feeding the polymer blend to an extruder;
- extruding the polymer blend through a die to form a first film or sheet material;
- and
- adhering the first film or sheet material to at least one second film or sheet material.
Dependencies are inferred from the claim text.