The invention relates to novel screw elements for multi-screw extruders with screw profiles co-rotating in pairs and being fully self-wiping in pairs, to the use of the screw elements in multi-screw extruders and to a process for extruding plastic compositions.

The present invention relates to screw elements with novel, tightly intermeshing, self-cleaning, co-rotating screw profiles for multishaft screw machines with pairs of co-rotating and fully abrading screw shafts, to the use of these screw elements in multishaft screw machines and to a method of generating these screw elements.

The kneading apparatus 1 includes a casing 2, a pair of elongated screws 4a, 4b rotatably provided in the casing 2. The screws 4a, 4b are arranged parallel and horizontally with respect to one another. The casing 2 has a main body 20 and a screw container 3 provided in the casing 2. The screw container 3 defines a kneading section 30 therein. The screw 4a includes a screw axis 41 having an outer periphery, a first screw member 42 provided on the outer periphery of the screw axis 41 and a kneading member 43 provided on the outer periphery of the screw axis 41. The first screw member 42 and kneading member 43 are provided in the kneading section 30. The screw 4a, the first screw member 42 and the kneading member 43 respectively have core portions 411, 412, 413 having a surface and outer layers 45 respectively provided on the surfaces of the core portions 411, 412, 413. The screw container 3 and the outer layers 45 are constituted of a nonmetallic material.

Melt pumps for producing synthetic granules, extruded profiles or molded parts are disclosed. One disclosed example melt pump for building up pressure at a fluid medium is to be used for pressing the medium through a tool. The example melt pump includes a compressor that comprises an inlet and an outlet opening, and at least two worm conveyors disposed in a common housing, where worm flights provided on the worm conveyors are configured in such a manner that a force feed of the medium occurs and where the worm conveyors are drivable by their own drive.

Provided are a molding screw and an FBI molding machine using the same for manufacturing resin molded articles for reduced manufacturing variation with use of a resin powder, an additive, and a mixture material constituted by an inorganic material or an organic material. The molding screw can include a feeding portion for feeding a molding material, a compressing portion, and a metering portion that extend continuously from the feeding portion. The feeding portion and the compressing portion each can be provided with a spiral flight. The flight of the compressing portion can include multiple sub flights that extend in a spiral manner in a screw axis direction. The sub flights can each have a polygonal shape with rounded corner portions, and are arranged such that the corner portions are shifted by a set angle with respect to the screw axis.

An Extruder for providing a flow of viscoelastic material such as rubber is disclosed herein. The extruder includes several zones (A, P, H, S), each assigned to a particular rheological function and arranged axially from an upstream end to a downstream end of the extruder and having an endless screw of given diameter (D). In each of the zones, at least one helicoidal flight extends radially from a central shaft of the screw over a height (h.sub.1), in a direction and with a pitch which are defined for each of the zones, and which is rotationally driven about an axis (XX) in a barrel. The barrel is provided with various structures to further assist with the flow of the viscoelastic material