An extruder screw includes a screw main body, conveyance portions, barrier portions, and paths. The raw materials, the conveyance of which is limited by the barrier portions, flow in from the entrance. The raw materials flowing in from the entrance flow through the paths in an opposite direction to a conveyance direction of the conveyance portions. The exit is opened in the outer circumferential surface of the screw main body at a position on an upstream side in the conveyance direction in the conveyance portions in which the entrance is opened.

An extruder screw includes a screw main body, conveyance portions, barrier portions, and paths. The raw materials, the conveyance of which is limited by the barrier portions, flow in from the entrance. The raw materials flowing in from the entrance flow through the paths in an opposite direction to a conveyance direction of the conveyance portions. The exit is opened in the outer circumferential surface of the screw main body at a position on an upstream side in the conveyance direction in the conveyance portions in which the entrance is opened.

A barrel of a plastics extruder or a plasticizing cylinder of an injection-molding machine includes the barrel or cylinder having a wall, at least one spiral recess formed in the wall, and at least one heating element arranged in one spiral recess. The barrel or cylinder has at least one cooling element arranged in another spiral recess and the spiral recesses extend parallel to one another along the surface of the barrel or cylinder. Also, the cooling element is formed as a tube and the tube is or can have a liquid cooling medium flowing therethrough.

An installation for producing a polymer melt for a porous film, in particular for a membrane film, comprises a planetary roller extruder. Said extruder is used to produce a flowable polymer melt from thermoplastics. The planetary roller extruder has a filling opening and a discharge side for delivering the polymer melt. A melt pump is further provided. The discharge side of the planetary roller extruder is connected to a downstream inlet side of the melt pump for further conveying the polymer melt. The connection is in the form of a pressure channel shielded from the ambient atmosphere or a pressure line shielded from the ambient atmosphere. The planetary roller extruder and the melt pump are designed and/or can be driven in such a manner that the polymer melt is applied or can be transferred under pressure at the melt pump on the inlet side.

A screw machine includes an inductive heating device for the processing of material to be processed. The inductive heating device is used to heat the material in a heating zone. In the heating zone, at least one housing portion is made of an electromagnetically transparent material at least partly, the material being non-magnetic and electrically non-conductive, whereas at least one treatment element shaft is made of an electrically conductive material at least partly. During the processing of the material, the inductive heating device generates an alternating magnetic field that produces eddy current losses in the at least one treatment element shaft, the eddy current losses leading to a temperature increase of the at least one treatment element shaft. The material is heated on the at least one heated treatment element shaft, in particular until it melts. The screw machine allows a simple and efficient melting of the material, with the result that a mechanical energy input and a resulting wear of the screw machine can be reduced significantly.

The devices relate to the nuclear, metallurgical, mining, machine-building and food industries and may be used in producing semi-finished products and items made via the extrusion of powders of composite, polymer and other plastic masses. A device for producing semi-finished products or items made of composite, or polymer, or plasticized powder materials includes a screw press with a housing and a screw within the housing. The housing and the screw each have at least one deformational portion with protrusions and may each be formed integrally with the protrusions or may be formed compositionally, having special insertable rings which are provided with protrusions. In carrying out all three device variants, the housing and the screw are formed compositionally, and have provided, on the deformational portions of a ring, stators, which are secured to neighboring portions of the housing, and rotors, which are secured to neighboring portions of the screw.

The present invention provides a system and method for quickly removing and installing a filament tube and nozzle in an FFF extrusion system. The system utilizes a primary manifold that includes a cooling block, a heating block and a quick-change mechanism. This primary manifold is adapted to mate a filament tube/nozzle assembly. The quick-change mechanism, which in a particular embodiment utilizes a recessed biased-bearing arrangement, enables the filament/nozzle assembly to be removed and inserted without the use of any tools, and without causing any significant downtime for the FFF extrusion system. Once removed, the filament tube/nozzle assembly can be refurbished by a technician, trained so as not to over torque the tube/nozzle threaded interface. This refurbishment (typically consisting of a cleaning and the installation of a new nozzle) could be accomplished off-line, without any impact on the continued use of FFF extrusion system.

Polymeric foam processing systems and methods.

A method for producing a thermoplastic moulding compound by means of an extruder (10), which comprises at least one feed zone (20), at least one mixing section (30), at least one venting section (40) and at least one discharge zone (50), wherein in the at least one feed zone (20) a water-containing first component and a second component are supplied, in the at least one mixing section (30) the thermoplastic moulding compound is mixed and contained water is evaporated, in the at least one venting section (40) water vapour is removed from the moulding compound and in the at least one discharge zone (50) the moulding compound is discharged. At least one of the mixing housings (31, 32) is kept at a temperature that is equal to or lower than the temperature of the moulding compound within the mixing section (30).

Filter device for a molding machine with at least one filter element for filtering plasticized material, in particular plasticized plastic, wherein, in a fluidically parallel arrangement relative to the at least one filter element, at least one valve element is provided, which is formed to prevent the plasticized material from flowing through the at least one valve element during an injection process in a closed position and to allow the plasticized material to flow through the at least one valve element in an open position, in order to make it possible to relieve the pressure on the at least one filter element after the injection process.