Single-sided cling stretch film
AssigneeParagon Films, Inc.
InventorGregory L. Dohrer
Life of this patent
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Abstract
This invention relates to a single-sided cling stretch wrap film wherein the A layer exhibits a high cling force. The opposite surface is cling-free and is fabricated from a polyolefin having a MFR less than or equal to 10.0. A particularly preferred film is an A/B/C thermoplastic film of high tensile strength. Pallet loads overwrapped with the film are neither torn or destroyed when separated from each other. The cling-free layer may contain a medium or high density polyethylene. The productivity in the fabrication of the polyolefin film is improved by the use of medium or high density polyethylene.
Claims19
A stretch wrap thermoplastic A/B/C film having minimum stretch capability of 200% comprising:
- a polyolefinic A layer having a cling force to the C layer between about 100 to about 350 g wherein the A layer is selected from the group consisting of polyethylene, atactic polypropylene, copolymers of ethylene and propylene, and polymers obtained from (i) ethylene and/or propylene and (ii) an ethylenically unsaturated monomer;
- a polyolefinic B layer having a tensile strength between about 4,000 to about 12,000 psi;
- and
- a C layer having a cling force in a non-stretched condition to another C layer according to ASTM D4649 of approximately zero wherein said C surface is fabricated from a film forming system free of a slip additive and comprising a polyethylene or polypropylene having a melt flow rate, in accordance with ASTM D-1238, less than 10.0.
A stretch wrap thermoplastic A/B/C film comprising:
- a polyolefinic A layer having cling force to the C layer wherein the A layer is selected from the group consisting of polyethylene, atactic polypropylene, copolymers of ethylene and propylene, and polymers obtained from (i) ethylene and/or propylene and (ii) an ethylenically unsaturated monomer;
- a polyolefinic B layer having a tensile strength between about 4,000 to about 12,000 psi;
- and
- a C layer having a substantially non-cling surface when in a non-stretched condition fabricated from a resin film forming system free of a slip additive and comprising a polyethylene or polypropylene having a MFR less than or equal to 10.0.
A stretch wrap thermoplastic film which comprises a surface having a cling property and an opposite surface having substantially no cling property and further wherein the cling-free surface is fabricated from a film-forming system containing a resin having an MFR less than or equal to 10.0 wherein said resin is selected from the group consisting of polyethylene and polypropylene.
Dependencies are inferred from the claim text.