A single-screw extruder for conveying and plasticizing a meltable material, including a screw and a heated cylinder, wherein the screw is rotatably held in the heated cylinder, the screw has a core and a helical main flight, which is at a first distance from the internal wall of the cylinder, a region of a transition zone and a melting zone has at least two successive, non-overlapping barrier portions, and a cylinder-side outside flight surface of one or more overflow flights is chamfered in full or in part over a flight width such that a conical gap that gets narrower in an overflow direction is formed between the internal wall of the cylinder and the cylinder-side outside flight surface.

A single-screw extruder for changing a morphology of superabsorbent polymer gel. The single-screw extruder has an input aperture, a channel, a screw and an output aperture. The screw in the invention has a first pitch value of a pitch of the screw flights along the conveying zone of the channel and, following in conveying direction, has a second pitch value of the pitch of the screw flights along the conveying zone of the channel, where the second pitch value is smaller than the first pitch value.

A single-screw extruder (100), and a method. The extruder (100) comprises—a cylindrical rotor member (1) having diameter (D) and length (L) and comprising a feeding zone (14), —the rotor member (1) arranged in a barrel (2), —the cylindrical surface of the rotor member (1) carrying cavity/cavities and/or projection(s) (5) arranged in helically extending rows, —the helically extending row(s) of the rotor member (1) having a pitch (P) and depth (d) in the feeding zone (14) of the rotor member, and the extruder (100) further compris-ing—a drive system (4) for the rotation of the rotor member (1) in the barrel (2). The relation of the depth (d) to the diame-ter (D) of the rotor member, i.e. d:D, is not more than 1:20, and the relation of the pitch (P) of the rotor member to the di-ameter (D) of the rotor member, i.e. P:D, is not more than 1:4.

An extrusion system, for example for extruding a food product, that includes: an extruder, which propels extrudate through an outlet of the extruder; and a valve. The valve includes: an inlet, which receives extrudate from the extruder outlet; a main conduit, which extends from the inlet to a main outlet; a dumping conduit, which extends from a junction with the main conduit to a dumping outlet; and a flow control member, which is operable to move between: a plurality of flow controlling positions, in which extrudate is directed to the main outlet, with the flow control member providing, for each flow controlling position, a respective amount of impedance to flow along the main conduit; and a flow diverting position, in which extrudate is directed along the dumping conduit to the dumping outlet.

It is provided an extruder for a system for the additive manufacture of freely formable metal parts with or without a supporting structure by means of an extrusion method from a composite material, which is arranged on a three-dimensionally movable kinematic mechanism, with a building platform. The extruder consists of a housing and a screw arranged in the housing. The extruder is provided with a mechanical drive for the composite material to be extruded, with an exchangeable nozzle, arranged on the housing, and the housing is connected to the mechanical drive by way of suitable means for transporting the composite material.

A reciprocating blow molding unit includes an extruder screw foundation and an extrusion unit coupled to the extruder screw foundation. The extruder screw foundation includes a screw housing formed to include an interior cavity configured to receive polymeric material. The extrusion unit includes an extruder screw arranged to lie at least partially within the interior cavity and is configured to rotate about a longitudinal rotation axis to advance the polymeric material through the interior cavity.

It is provided an extruder for a system for the additive manufacture of freely formable metal parts with or without a supporting structure by means of an extrusion method from a composite material, which is arranged on a three-dimensionally movable kinematic mechanism, with a building platform. The extruder consists of a housing and a screw arranged in the housing. The extruder is provided with a mechanical drive for the composite material to be extruded, with an exchangeable nozzle, arranged on the housing, and the housing is connected to the mechanical drive by way of suitable means for transporting the composite material.

A screw has a spiral blade for extruding and kneading a high-silica plastic elastomer containing not less than 100 phr of silica. The screw has a first section located on the most downstream side in the extrusion direction and provided with a barrier extending between the adjacent spiral blade threads, while inclining with respect to the screw axial direction. The length of the barrier is 1.5 to 3.0 times the lead length of the spiral blade in the first section. The height of the barrier is 2 to 10 mm lower than the height of the spiral blade. The barrier thickness is 0.9 to 3.0 times the height difference between the spiral blade and barrier.

Apparatus and methods for manufacturing compostable, biodegradable drink straws from polyhydroxyalkanoate (PHA) material are disclosed herein. Such apparatus may include a hopper that contains raw PHA material, an extruder that receives the raw PHA material from the hopper and produces extruded PHA material, one or more waters baths that cool the extruded PHA material, a puller that pulls a tubular stream of PHA material through the system, and a cutter that is configured to cut the stream of PHA material into finished straws. The finished straws may be soil- and marine-biodegradable, as well as home- and industrial-compostable.

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.