A method for reducing sharkskin melt fracture during extrusion of ethylene polymers

摘要

A method for reducing sharkskin melt fracture during extrusion of a molten narrow molecular weight distribution linear ethylene polymer which comprises extruding said polymer through a die having a die gap greater than about 50 mils and wherein at least a portion of one surface of the die lip and/or die land in contact with the molten polymer is at an angle of divergence or convergence relative to the axis of flow of the molten polymer through the die.