An extruder screw for a multi-screw extruder for plastics extrusion includes: a feeding and metering zone for melting and homogenizing the plastic and an evacuating zone for carrying away gaseous constituents and a compressing and/or discharging zone; a multi-screw section, which has a plurality of planetary screws, which lie open on the outer circumference of the extruder screw, at least over part of their length; and a driving zone, in which the planetary screws engage by way of a toothing in an external toothing on a central shaft or in an internal toothing in a stator ring or in the inner wall of an extruder bore of the multi-screw extruder. The feeding and metering zone extends into the multi-screw section, wherein the respective part of the planetary screws that is lying in the metering zone is at least partially enclosed.

An extruder screw for the plasticizing of at least one plastic material or a plastic material mixture, with a melting zone, a wave zone and a mixing zone arranged between the melting zone and the wave zone, wherein a conveying web extending in a helix-like manner along a screw longitudinal axis is formed in the melting zone and in the wave zone, wherein a conveying web of the melting zone terminates at an end of the melting zone facing the mixing zone, and a conveying web of the wave zone begins at an end facing the mixing zone. The application also relates to an extrusion device with this extruder screw, and a method for plasticizing at least one plastic material or a plastic material mixture.

Rheology-modified, additive-containing ethylenic polymer compositions are prepared in a continuously operated extruder comprising first, second and third zones by a process comprising the steps of: mixing in the second zone of the extruder an ethylenic polymer and a high-temperature decomposing peroxide at a temperature such that the half-life of the peroxide is equal to or greater than one minute and for a sufficient period of time to modify the rheology of the ethylenic polymer to produce a rheology-modified, melted ethylenic polymer for transfer to the third zone of the extruder; and adding to the third zone one or more additives to the rheology-modified, melted ethylenic polymer to produce the rheology-modified, additive-containing ethylenic polymer.

The biodegradable composite insulation material is a composite of wood from the date palm tree (Phoenix dactylifera) and polylactic acid. The composite may have up to 50 wt % date palm wood powder of maximum particle size of 212 m, the balance being polylactic acid (PLA). The composite may be prepared by melt blending the date palm wood powder with polylactic acid pellets in a twin screw extruder at 190 C., followed by compression molding the blend in a press or the like into the desired shape for building thermal insulation, and finally, annealing the molded product for three hours at 95 C. The composite material is biodegradable, thermally insulating, water-resistant and relatively strong.

A method in which a stream of dry cementitious powder from a dry powder feeder passes through a dry cementitious powder inlet conduit to feed a first feed section of a fiber-slurry mixer. An aqueous medium stream passes through at least one aqueous medium stream conduit to feed a first mixing section the fiber-slurry mixer. A stream of reinforcing fibers passes from a fiber feeder through a reinforcing fibers stream conduit to feed a second mixing section of the fiber-slurry mixer. The stream of dry cementitious powder, aqueous medium stream, and stream of reinforcing fibers combine in the fiber-slurry mixer to make a stream of fiber-cement mixture which discharges through a discharge conduit at a downstream end of the mixer.

A device for producing a dyed plastic melt and an undyed plastic melt includes a multi-shaft screw extruder, a first metering installation, a second metering installation, and a control installation for selecting between a first operating mode for producing the dyed plastic melt and a second operating mode for producing the undyed plastic melt. The first metering installation serves for feeding an undyed plastic material through a first infeed opening into a housing of the multi-shaft screw extruder, and the second metering installation serves for feeding at least one dyeing agent through a second infeed opening into the housing. In order for the undyed plastic melt to be produced, the plastic material is fed exclusively via the first infeed opening such that residual dyeing agent which is still located in the second metering installation or in the region of the second infeed opening does not contaminate the undyed plastic melt.

The present invention discloses a biaxial or tri-axial eccentric rotor volume pulsed deformation plasticizing method and device. The method is characterized in that: the conveying volume of materials formed between two or three engaged eccentric rotors, which are formed by spiral structures and eccentric cylindrical structures connected alternately, and an inner surface of a stator changes periodically along the axial direction and the radial direction of the rotors, achieving the volume pulsed deformation plasticizing and conveying of the materials during engaged rotation of the two or three engaged eccentric rotors. The device's eccentric rotors are all formed by length-varying spiral structures and eccentric cylindrical structures connected alternately; the spiral structures of the eccentric rotors are engaged to each other; the axial positions of eccentric cylindrical structures of the two or three rotors are the same. The present invention can implement extrusion of polymer materials or implement, in combination with a plunger injection unit, injection molding of polymer materials, and have many features such as desirable mixing and plasticizing effects for materials, a short thermo-mechanical course, low power consumption, and wide adaptability.

There is provided with a screw that is inserted into a cylinder an inside of which a material is loaded, and is rotatably supported in both end portions on an upstream side and a downstream side, or in an end portion on the upstream side, in the cylinder; a first kneading blade including a plurality of first blades that are helically provided on the screw and send the material toward the downstream side with rotation of the screw; and a second kneading blade including a second blade that is helically provided on the screw and returns the material, which is sent toward the downstream side by the first kneading blade, toward the upstream side, the number of blades in the second blade being smaller than the number of blades in the first blade.

A screw extruder for extruding a kneaded material includes a screw and a casing housing the screw and having a material supply port on an upstream side in an extrusion direction of the kneaded material and a tip-side opening on a downstream side in the extrusion direction. A pressure sensor for measuring a pressure inside the casing is provided between a downstream end of the supply port and the tip-side opening of the casing. A rotational speed of the screw is controlled depending on the pressure measured by the pressure sensor.

Provided is a method for producing a shaping material that contains a cyclic olefin polymer and has a low content of a volatile impurity. This method for producing a shaping material is a method which includes passing a raw-material resin in a molten state through an extruder to produce a shaping material, and in which the extruder is equipped with a cylinder, a screw housed within the cylinder, a resin introduction port for introducing the raw-material resin into the cylinder, a resin discharge port for discharging the molten resin from the cylinder, a fluid injection port for injecting carbon dioxide or water into the cylinder between the resin introduction port and the resin discharge port, and a fluid discharge port for removing fluid in the cylinder by suction downstream of the fluid injection port and between the resin introduction port and the resin discharge port.