Abstract: A process for reducing die drool during extrusion of highly filled polymeric resins for production of jacketing insulation for wire and cable by incorporating into the surface of the die in contact with said resin a compound which decreases the adhesiveness between the polymeric resin and the die surface, said compound being employed in an amount sufficient to reduce die drool.

Abstract: A process for reducing draw resonance of a polymeric molten film susceptible to draw resonance under conditions which would cause draw resonance by extruding the film from a die and rapidly cooling said film in a rapid cooling zone containing a pressure roll and chill roll by providing a tensioning device between said die and the nip of said pressure and chill roll, said tensioning device providing a substantially friction free surface with respect to said moving film.

Abstract: Low level irradiation of narrow molecular weight distribution, linear, low density ethylene/alpha-olefin copolymer sufficient to introduce crosslinks into the copolymer but insufficient to provide for significant gelation produces improved copolymer rheology providing superior film fabrication.

Abstract: A process for producing polymeric film substantially free of draw resonance under conditions and at rates which would otherwise cause draw resonance in polymeric film susceptible to draw resonance wherein a fluid medium is directed against the moving film at a location between the extrusion die and the film take-up zone.

Abstract: Method and apparatus for testing thermoplastic material comprising: passing as a stream a fractional, continuous, molten and flowable sample of the material to and successively through each of either a controllable pumping zone maintained at constant temperature and pressure or controllable pressure zone maintained at constant flow rate and temperature, and a die zone to form a continuous strand of the material; measuring the viscosity of the material in the pumping and die zones; providing a measurement of elasticity by obtaining a measurement of percentage of cross-section area swell in the strand in passage from the die zone over a constant length distance downstream of a point of strand marking to a point of strand marking to a point of mark sensing; and combining the viscosity measurement with the elasticity measurement to provide fuller rheological characterization data for the material.

Abstract: In a single screw extruder mixer head for mixing high viscosity linear polyolefins materials employing a plurality of alternate longitudinal mixing and wiping barriers, the improvement of providing longitudinal radially-stepped regions on the opened bevelled leading edge portions of the outer surface of the wiping barriers to act as hydrodynamic wedges to the passage of polyolefin material passing between the surfaces and the inner walls of the extruder barrel; and radially-stepped opened bevelled leading edge portions of the outer surfaces of the wiping barriers and the outer circumferential surfaces of full diameter of the mixer head supporting an outer coating of gall-resistant material.

Abstract: A multilayer plastic film free of melt fracture suitable for use in packaging and making bags wherein the film comprises a core layer of low melt index, low pressure, low density polyethylene, and two outer layers of a high melt index, low pressure, low density polyethylene. The process of making the multilayer film is also disclosed.

Abstract: A process for reducing melt fracture formed during extrusion of a molten narrow molecular weight distribution, linear, ethylene polymer, which comprises extruding said polymer through a die having a discharge outlet defining an exit die gap formed by opposing die lip surfaces and wherein one surface of the die lip and/or die land in contact with the molten polymer extends beyond the opposing surface of the die lip and/or die land in the direction of the axis of flow of the molten polymer through the die exit and wherein said extended die lip has a groove extending around said extended die lip, said groove being disposed opposite the leading edge of the opposing die lip surface whereby melt fracture is reduced on both surfaces of the polymer leaving said die exit.

Abstract: A process for reducing melt fracture formed during extrusion of a molten narrow molecular weight distribution, linear, ethylene polymer, which comprises extruding said polymer through a die having a discharge outlet defining an exit die gap formed by opposing die lip surfaces and wherein one surface of the die lip and/or die land in contact with the molten polymer extends beyond the opposing surface of the die lip and/or die land in the direction of the axis of flow of the molten polymer through the die exit whereby melt fracture is reduced on the surface of the polymer leaving the extended die lip surface.

Abstract: An extrusion coating composition and a process for the extrusion coating of a substrate or article. The extrusion coating composition is comprised of greater than 20 and less than 98 weight percent of a high pressure low density polyethylene homopolymer and/or copolymer and greater than 2 and less than 80 weight percent of at least one linear low density ethylene hydrocarbon copolymer.

Abstract: A process and apparatus are disclosed for forming blown film of a low strain hardening polymer, such as a low pressure polymerized-low density ethylene copolymer, including an improved film bubble cooling technique which permits high production rates to be achieved with good film bubble stability. The disclosed process comprises cooling a molten film bubble by contacting the outside of the film bubble with separate annular streams of cooling fluid fed through at least two stacked annular cooling rings disposed around the film bubble, wherein all or substantially all of the cooling fluid exits the system through a common plane formed by the last cooling ring.

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 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.