The present invention relates to a multishaft extruder having screw shafts that rotate in the same sense and at the same speed, wherein these screw shafts each have at least one region having a special arrangement of screw elements, wherein the screw elements have an asymmetrical cross-sectional screw profile. In this case, these in each case at least one regions are situated directly opposite on directly adjacent screw shafts. The present invention also provides for the use of the extruder of the invention for processing or production of plastic or viscoelastic masses.

A counter-rotating differential speed extrusion device includes a barrel and a screw mechanism in the barrel comprising a first and second screws. A crest diameter and a root diameter of the first screw are respectively meshed with that of the second screw; the first and second screws counter-rotate in differential speeds at a fixed rotation speed ratio; at least one first intermediate circular arc structure with a trend consistent with that of the crest diameter and the root diameter of the first screw is provided between the root diameter and the crest diameter of the first screw, a second intermediate circular arc structure tangent to the first intermediate circular arc structure and having a trend consistent with that of the root diameter and the crest diameter of the second screw is provided between the root diameter and the crest diameter of the second screw.

A counter-rotating differential speed extrusion device includes a barrel and a screw mechanism in the barrel comprising a first and second screws. A crest diameter and a root diameter of the first screw are respectively meshed with that of the second screw; the first and second screws counter-rotate in differential speeds at a fixed rotation speed ratio; at least one first intermediate circular arc structure with a trend consistent with that of the crest diameter and the root diameter of the first screw is provided between the root diameter and the crest diameter of the first screw, a second intermediate circular arc structure tangent to the first intermediate circular arc structure and having a trend consistent with that of the root diameter and the crest diameter of the second screw is provided between the root diameter and the crest diameter of the second screw.

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.

A process for extruding plastic compositions is provided. The process comprises providing a multi-screw extruder with screw elements and conveying, kneading, mixing, degassing or compounding the plastic compositions in the multi-screw extruder using the screw elements.

A process for extruding plastic compositions is provided. The process comprises providing a multi-screw extruder with screw elements and conveying, kneading, mixing, degassing or compounding the plastic compositions in the multi-screw extruder using the screw elements.

Systems for producing superabsorbent polymer particles for use in agricultural applications are disclosed. A monomer is graft polymerized onto a starch to form a starch graft copolymer. The moisture content of the starch graft copolymer is reduced through use of an extruder.

Systems for producing superabsorbent polymer particles for use in agricultural applications are disclosed. A monomer is graft polymerized onto a starch to form a starch graft copolymer. The moisture content of the starch graft copolymer is reduced through use of an extruder.

An mixing section for an extrusion screw has an inlet end and an outlet end as well as alternating wiping lands and barrier lands. The wiping lands have a greater helix angle than the barrier lands. The wiping lands and the barrier lands define inlet channels which narrow toward the outlet end and outlet channels which widen toward the outlet end. A helical pattern of mixing channels is cut into the wiping lands and the barrier lands. The mixing channels may be oriented generally at approximately right angles to the wiping lands and the barrier lands. A portion of the extrudate encounters the inside wall surfaces of the mixing channels and changes direction which improves the mixing of the extrudate.