Multilayer stretch/shrink film
AssigneeViskase Corporation
InventorDonald J. Ralph
Life of this patent
Estimating the term…
Abstract
A biaxially oriented heat shrinkable multilayer stretch film useful as a trayed poultry overwrap includes outer layers each comprising a blend of VLDPE (density below about 0.914 g/cm.sup.3 and an ethylene alpha-olefin plastomer (density below about 0.90 g/cm.sup.3).
Claims6
In a hermetically sealed and evacuated food package comprising a tray with a bottom section surrounded by upwardly extending side walls, perishable food supported on the upper surface of said bottom section, and a stretched heat shrink film extending over each said food, the upper edges of said side walls and at least part of the lower surface of the tray bottom section and heat sealed to itself in flattened relationship against said lower surface so as to form with said tray a hermetically sealed enclosure for said food:
- the improvement of a biaxially oriented multilayer composition as said stretched heat shrink film comprising at least a first outer layer, a second outer layer, and a core layer between said first and second outer layers, said first and second outer layers each comprising a blend of between about 20 and about 35 weight % ethylene alpha-olefin plastomer copolymer of density at least 0.912 and below about 0.90 g/cm.sup.3, and between about 65 and about 80 weight % VLDPE of density below about 0.914 g/cm.sup.3, and said core layer comprising ethylene alpha-olefin copolymer having a higher melting point than the melting point(s) of either of said first and second outer layers.
In a hermetically sealed and evacuated food package comprising a tray with a bottom section surrounded by upwardly extending side walls, perishable food supported on the upper surface of said bottom section, and a stretched heat shrink film extending over each said food, the upper edges of said side walls and at least part of the lower surface of the tray bottom section and heat sealed to itself in flattened relationship against said lower surface so as to form with said tray a hermetically sealed enclosure for said food:
- the improvement of a biaxially oriented multilayer composition as said stretched heat shrink film comprising at least a first outer layer, a second outer layer, and a core layer between said first and second outer layers, said first and second outer layers each comprising a blend of between about 20 and about 35 weight % ethylene alpha-olefin plastomer copolymer of density below about 0.90 g/cm.sup.3, and between about 65 and about 80 weight % VLDPE wherein said VLDPE comprises a blend of a first ethylene alpha olefin having a density of about 0.912 g/cm.sup.3 and a second ethylene alpha olefin which is a butene comonomer having a density of about 0.900 g/cm.sup.2, a melt index of about 3.5, a melting point of about 92.degree. C. and an Mw/Mn of about 2, and said core layer comprising ethylene alpha-olefin copolymer having a higher melting point than the melting point(s) of either of said first and second outer layers.
Dependencies are inferred from the claim text.