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US 4,243,619 AGranted
Process for making film from low density ethylene hydrocarbon copolymer
AssigneeUnion Carbide Corporation
InventorsWilliam A. Fraser, Gary S. Cieloszyk
Life of this patent
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Abstract
A process for making film from a narrow molecular weight distribution low density ethylene hydrocarbon copolymer, which process comprises extruding said copolymer through a die gap of greater than about 50 mils. The film exhibits an excellent balance of optical and mechanical properties.
Claims25
A process for forming blown tubular film essentially free of melt fracture from an extrudate formed from molten ethylene hydrocarbon copolymer,
- said copolymer having been made from .gtoreq.90 mol percent of ethylene and .ltoreq.10 mol percent of at least one C.sub.3 to C.sub.8 alpha olefin monomer with a transition metal based catalyst and having a narrow molecular weight distribution and a melt index of about .gtoreq.0.1 to about .ltoreq.5.0 and being susceptible to melt fracture in blown tubular film form when extruded into such form through an extrusion die having a die gap of 15 to .ltoreq.45 mils, which comprises extruding said copolymer into such form through an extrusion die having a die gap of greater than about 50 mils and at a drawdown ratio of greater than about 2 to less than about 250.
Dependencies are inferred from the claim text.