A conveyance portion, a barrier portion, and a path are provided at places of a portion of a screw main body in which a kneading portion is provided. In at least one of the places, an entrance is opened to cause raw materials, conveyance of which is limited by a barrier portion to increase pressure on the raw materials, to flow in. The raw materials flowing in from the entrance flow through the path in the opposite direction to a conveyance direction of the conveyance portion. An exit is opened in an outer circumferential surface of the screw main body at a position outside the conveyance portion in which the entrance is opened.

The present invention relates to a novel die assembly for the melt extrusion of ultra-high molecular weight polyethylene (UHMWPE) comprising a tapered channel section, and a process for pelletising UHWMPE using such die assembly. Using the die assembly according to the invention, UHMWPE pellets having improved mechanical properties such as tensile strength, improved density, and reduced oxidation index can be obtained.

Provided is a method for producing a resin composition from which can be formed a molded body having excellent tensile elongation and/or rigidity, and more preferably a molded body which stably achieves both high tensile elongation and high rigidity. An aspect of the present invention provides a method for producing a resin composition which contains a first component and a second component, said method comprising a kneading step for kneading the first component and the second component via an extruder provided with a kneading zone that includes a plurality of narrow gap zones in which the gap between a cylinder inner wall and a screw is not more than 2 mm. An aspect of the present invention provides a method for producing a resin composition which contains a first component and a second component, said method comprising a kneading step for kneading the first component and the second component via an extruder provided with a kneading zone that includes a plurality of high-pressure zones in which the pressure is not less than 0.1 MPa, wherein out of the plurality of high-pressure zones, a maximum pressure zone in which the pressure is the highest has a pressure [P1] of not less than 0.5 MPa, and the ratio [P1/P2] of the pressure [P1] to the average value [P2] of pressures in high-pressure zones other than the maximum pressure zone is greater than 1 but not greater than 100.

An extruder screw for a multi-screw extruder, having an intake and metering section. A rotor body has an enlarged diameter relative to the intake and metering section and has a plurality of satellite screws positioned on the outer periphery of the rotor body at least over part of the length thereof. A cone and an adjoining drive zone are formed between the intake and metering section and the rotor body, in which drive zone the satellite screws each engage via a drive pinion in an external toothing on the rotor body or in an internal toothing on a stator ring or in the inner wall of an extruder housing. At least one peripherally closed flow channel is formed, which flow channel extends from an inlet opening on the cone to an outlet opening located downstream of the drive pinions in the direction of flow.

A biaxial continuous kneading extrusion device (10) includes a biaxial kneading feeder (16) including two passage sections (11, 12) arranged in parallel in a state of communication with each other, and first and second kneading feed shafts (14, 15) rotatably arranged in the two passage sections, respectively, to knead a supplied material and a uniaxial screw section including a single passage section that receives the material fed out from the biaxial kneading feeder, and a separate screw shaft rotatably disposed in the single passage section to extrude the material. In each of the first and second kneading feed shafts, a mixing rotor is formed in at least one section in an axial direction, a maximum outer diameter section is formed in a section of an outer periphery of the mixing rotor, and a chip clearance is formed between the maximum outer diameter section and inner walls of the passage sections.

A planetary roller extruder for homogenizing, dispersing, pasteurizing, and purposefully controlling the temperature of biodegradable materials that are prone to altering their properties during processing, in particular the properties that rule out further use after the materials have been processed, such as food, medicinal products or pharmaceutical products, different regions being present in the planetary roller extruder. The planetary roller extruder includes a flow conduit having various transitions from one region to a next region in an interior and components being statically and movably installed. A seal is installed between statically installed components, by which seal gaps or cavities present are configured to be closed. A slide ring seal provides sealing between moving components, which are led from the flow conduit in the interior outward to a surrounding area, so as to avoid steps and/or notches along flow surfaces in a transition region of the moving components.

A screw extruder includes a tapered screw having a shaft portion and a wing portion, a driving device that rotates the tapered screw, a casing having a passage port through which a material passes, and a die plate attached to the casing so as to close the passage port. The die plate has a first discharge perforation arranged at a position corresponding to the tapered screw. During rotation of the tapered screw, size of an overlapping region between a top surface of the wing portion of the tapered screw and the first discharge perforation when viewed in a material extrusion direction changes periodically. A material extruded by the tapered screw is cut by increase in the overlapping region between the first discharge perforation and the top surface of the wing portion.

A multi-shaft preparation unit for plastic melts, having an extruder housing with an enclosed treatment chamber in its interior, and at least one rotor body shaft mounted rotatably in the treatment chamber and a sealing and guiding body with multiple recesses, in each of which a satellite screw is mounted. The multi-shaft preparation unit has a drive unit in which a gearing unit is arranged outside the extruder housing between a drive motor and the treatment chamber and is connected to the drive shaft sections of the rotor body shaft and of the satellite screws which lead out of the treatment chamber of the extruder housing. A separating device for decoupling a flow of fluid and/or heat emanating from the treatment chamber is provided between the extruder housing and the gearing unit, through which the drive shaft ends of the rotor body shaft and of the satellite screws pass.