Abstract: A continuous pelletizing system for pelletizing synthetic thermoplastic materials which includes:(1) a melter/mixer for at least partially melting and mixing synthetic thermoplastic material;(2) a gear pump operatively associated with the melter/mixer for increasing pressurization of the melted synthetic thermoplastic material;(3) an independently controlled dispersive mixer operatively associated with said gear pump or the melter/mixer which provides additional independent mixing of the melted synthetic thermoplastic material; and(4) a pelletizer operatively associated with the independently controlled dispersive mixer or the gear pump for forming pellets of synthetic material.

Abstract: A process for forming a blown film from a thermoplastic resin wherein a source of cooling air is induced to flow from the atmosphere in contact with another source of pressurized cooling air whereby increased production rates can be obtained.

Abstract: A method is disclosed for the extrusion of low-density linear polyolefin materials having high viscosities, wherein such materials are continuously fed to and through a rotary extruder having feeding, transition and metering sections which comprises employing, in the extruder screw forming such sections in cooperation with the cylindrical interior of the extruder housing, opened leading edges for the screw flights of said sections; and gall-resistant coated surfaces on the screw flights of said sections.

Abstract: A method for extruding granular low density narrow molecular weight distribution linear ethylene polymers which comprises passing said granular polymers into an extrusion apparatus including an extruder screw, said extruder screw having a feed section wherein said polymers are introduced and thence passed through a transition section and a metering section, wherein each lead in the feed section is substantially the same and each lead in the metering section is substantially the same and wherein each lead in the feed section is 5 to 50 percent greater than each lead in the metering section.

Abstract: 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.

Abstract: A method for reducing the melt fracture during extrusion of a molten narrow molecular weight distribution 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.