Lower discharge temperatures and improved flow rates are obtained for the processing of meltable, solid crosslinkable compositions comprising a polymer, e.g., polyethylene, and a peroxide, in a single barrel extruder by equipping the extruder with an energy transfer (ET) screw that comprises: (1) an ET section with a distance averaged ET section depth of 8.0% to 10% of the extruder barrel internal diameter, and (2) a metering section with a metering section depth of 6.0% to 8% of the extruder barrel internal diameter.

A no solid bed extruder screw for processing a material to a molten state has a body with a helical thread formed thereon, the thread having pushing and trailing surfaces. The body has an outer surface and extends longitudinally between feed and discharge ends. A channel for receiving the material to be processed is defined between the outer surface of the body and an outer diameter of the thread bounded by the pushing surface and the trailing surface of the thread. A volume of the channel decreases in a plurality of revolutions of the thread in a direction from the feed end to the discharge end. A channel depth between the pushing surface and the trailing surface decreases for a first portion of the channel toward the feed end and increases for a second portion of the channel toward the discharge end.

A no solid bed extruder screw for processing a material to a molten state has a body with a helical thread formed thereon, the thread having pushing and trailing surfaces. The body has an outer surface and extends longitudinally between feed and discharge ends. A channel for receiving the material to be processed is defined between the outer surface of the body and an outer diameter of the thread bounded by the pushing surface and the trailing surface of the thread. A volume of the channel decreases in a plurality of revolutions of the thread in a direction from the feed end to the discharge end. A channel depth between the pushing surface and the trailing surface decreases for a first portion of the channel toward the feed end and increases for a second portion of the channel toward the discharge end.

A die structure is provided. The die structure may have a die body, a mandrel having a magnet and/or one or more magnet assemblies, a first magnetic structure, a second magnetic structure and/or one or more magnetic structures. The first magnetic structure may be configured to apply a first magnetic force to the mandrel, in a first direction. The second magnetic structure may be configured to apply a second magnetic force to the mandrel, in a second direction opposite the first direction. The one or more magnetic structures may be configured to apply one or more magnetic forces to the mandrel. Application of the first magnetic force, the second magnetic force and/or the one or more magnetic forces to the mandrel supports the mandrel to be levitated within the die body and/or causes the mandrel to rotate and/or to maintain a position within the die body.

A plasticating screw is proposed, with a screw channel, which runs spirally around a screw core, is laterally delimited by a flight (1), (2) and has flow elements (3), (4) that are distributed over its longitudinal direction, extend transversely over the screw channel and comprise a deep section (5) and a compression section (6), rising radially in the longitudinal direction. In order to design a plasticating screw of the type mentioned at the beginning in such a way that its length is reduced and good melting characteristics can be achieved even with little energy input, it is proposed that the compression section (6) forms at least one run-up surface (7), which is inclined towards the flight (1), (2) and is adjoined in the longitudinal direction by a plateau (8) for forming the flow.

A plasticating screw is proposed, with a screw channel, which runs spirally around a screw core, is laterally delimited by a flight (1), (2) and has flow elements (3), (4) that are distributed over its longitudinal direction, extend transversely over the screw channel and comprise a deep section (5) and a compression section (6), rising radially in the longitudinal direction. In order to design a plasticating screw of the type mentioned at the beginning in such a way that its length is reduced and good melting characteristics can be achieved even with little energy input, it is proposed that the compression section (6) forms at least one run-up surface (7), which is inclined towards the flight (1), (2) and is adjoined in the longitudinal direction by a plateau (8) for forming the flow.

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.

Systems for molding products that include sheer sensitive materials are disclosed. The systems may include a barrel. A hopper may be in communication with the barrel. A screw may be disposed within the barrel. The screw may be designed to rotate and reciprocate within the barrel. The screw may include a metering section. A plurality of dome members may be coupled to the screw and disposed along the metering section.

An extruder and an LFT extrusion member manufactured thereby, and the extruder uses a long fiber thermoplastic (LFT) as a raw material to produce LFT extrusion members such as LFT sheets, pipes and profiles by a continuous extrusion molding process. The structural improvement of the extruder screw, including the screw body having three different thread groove deep sections, in sequence, a feed section, a compression section and a metering section, so that the LFT extrusion member produced by the extruder has high strength, high stiffness, high dimensional stability, low warpage and resistance to creep.

An apparatus for producing a foam-molded product, including a plasticizing cylinder which has a plasticization zone for plasticizing and melting a thermoplastic resin into a molten resin and a starvation zone for allowing the molten resin to be in a starved state and which is formed with an introducing port for introducing a physical foaming agent into the starvation zone; and a physical foaming agent supply mechanism which supplies the physical foaming agent to the plasticizing cylinder via the introducing port, wherein the introducing port is open at all times, and the physical foaming agent having a fixed pressure is continuously introduced into the starvation zone from the physical foaming agent supply mechanism via the introducing port during the producing of the foam-molded product.