Extrusion apparatus and methods for use in the design and operation of extrusion screws having multiple channels. In response to rotation of an extrusion screw in an extrusion process, the multiple channels of the extrusion screw can control the temperature, pressure, and/or shear rate of feedstock material flowing through the respective channels. The multiple channels of the extrusion screw can be configured to control the temperature, the pressure, and/or the shear rate of the processed feedstock material by being modeled as one or more model objects having one or more predetermined geometries. The models of the respective channels can then be analyzed using computerized analytical and/or numerical techniques in order to obtain at least estimates of desired temperatures, pressures, and/or shear rates of the processed feedstock material, based at least on specified channel lengths, channel widths, and/or channel depths of the respective channel models.

High Specific Mechanical Energy extruder screw assemblies (14, 88, 98) and complete extruders (10, 86, 96) are provided, which include wide-flight intermediate screw sections (104) having axial flight widths greater than the flight widths of the inlet and outlet screw sections (102, 106) on opposite sides of the intermediate sections (104). The intermediate sections (104) provide increased friction and shear serving to enhance the SMEs imparted to comestible food materials during processing thereof.

A subject of the invention is a process for surfacing or resurfacing a metal part by laser-assisted deposition of a filler material in order to produce an abradable coating of the part, the process being characterized in that the filler material is an iron-based powder comprising vanadium, chromium, nickel, boron, silicon and carbon, in that the laser has an operational wavelength ranging from 900 nm to 1100 nm and in that it comprises the irradiation of the part by a laser beam such that the specific energy (SE) varies from 5 J/mg to 10 J/mg and such that the linear density (LD) varies from 25 mg/mm to 55 mg/mm. Another subject of the invention is the surfaced or resurfaced metal part. Another subject of the invention is a pre-alloy in iron-based powder form, comprising vanadium, chromium, nickel, boron, silicon and carbon.

A planetary roller extruder. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. 1.72(b). As stated in 37 C.F.R. 1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading Abstract of the Disclosure. The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

The invention sets out a method for simply producing components which are suitable for use under high loads and risks of wear and which have a core portion which consists of a metal material and a wear-resistant layer on a peripheral surface of the core portion. To this end, there is provided according to the invention a) a core portion blank which consists of the metal material and whose dimension in a first spatial direction is greater than the desired finished dimension of the core portion of the component in the relevant spatial direction and whose dimension in a second spatial direction is smaller than the desired finished dimension of the core portion of the component in this second spatial direction; b) there is applied a material which forms the wear-resistant layer to the peripheral surface in such a manner that the material and the core portion blank form a stable composite body; and c) the composite body is shaped to form the component by the composite body being extended in the direction of the second spatial direction and being compressed in the direction of the first spatial direction until the dimensions thereof in the spatial directions at least correspond to the desired finished dimensions of the component in these spatial directions and the wear-resistant material is present on a peripheral surface of the component. Optionally, finishing processing of the component may follow.

The present invention relates to new screw elements for multi-screw extruders with pairs of co-rotating and fully wiping screws.

A method for preparation of decontaminated natural rubber is provided. The method is characterized in that it comprises a decontamination step in which wet natural rubber coagulum passes through a system comprising an extruder and a filter installed at the extruder outlet, the extruder comprising an axially symmetrical grooved sheath comprising in its thickness grooves opening on the inner surface of the sheath.

A screw to be used in an extruder has a modular structure so that it can be adapted very flexibly to new tasks and conditions. The modular structure of a screw contains a rod-shaped mandrel and individual screw components which are slidable onto the mandrel. The components perform the classic functions of the screw during the extrusion process, such as conveying, kneading, mixing or shearing of the plastic to be guided into and through the plant.

For transmission of the occurring high torque, the components are connected with the mandrel so that they positively engage and are axially braced in addition. The connection is to be performed such that it can be released by simple means.

The invention relates to a process for extruding plastic compositions, in particular polymer melts and mixtures of polymer melts, above all thermoplastics and elastomers, particularly preferably polycarbonate and polycarbonate blends, also with the incorporation of other substances such as for example solids, liquids, gases or other polymers or other polymer blends with improved optical characteristics, with the assistance of a multi-screw extruder with specific screw geometries.

A screw used in an extruder and an extruder having such a screw, in particular a screw used in a multiple-screw extruder and a multiple-screw extruder uses an additional connecting element directly leading from one segment to the next in order to relieve the mandrel. The screw includes a mandrel and a plurality of segments borne by the mandrel and arranged axially with respect to one another, a segment border between a first segment and an axially adjacent second segment has a separate cylindrical connecting element adapted to transmit a torque over the segment border. The ratio of a length of the connecting element to the diameter of the connecting element is higher than 11.