Abstract: A twin screw extruder has a casing with a working direction, two partially intersecting casing bores, which are parallel to each other, two shafts, which are disposed in the casing bores and which are drivable to rotate in the same direction of rotation about an axis of rotation, the axes of rotation having a distance A from each other, and single-flight kneading disks, which are fixed on the shafts and have surface lines extending parallel to the respective axis of rotation. The kneading disks, in a cross-section perpendicular to the axis of rotation, have a crest, which is formed as a segment of a circle about the respective axis of rotation and which has a crest angle b and a radius RA, a bottom, which is formed as a segment of a circle about the respective axis of rotation and has a bottom angle g and a radius RI and two flanks, which join the crest and the bottom, RA>RI, A≈RA+RI and 0°≦b≦45° applying.

Abstract: A multi-shaft screw-type extruder having a casing with two parallel intersecting casing bores and two shafts drivably disposed in the casing bores. Screw elements intermeshing kneading disks are fixed on the shafts The widths of the respective crest portions of the kneading disks are smaller than the disk width and form mixing-and-scraping-studs on the periphery of the disks. The mixing-and-scraping-studs on each kneading disk are axially misaligned relative to each other such that their peripheral faying surfaces jointly cover the entire disk width.

Abstract: A screw-type extruding machine includes a housing; a driveable shaft disposed inside the housing and including a rotational moment transfer element; and at least one screw element. The screw element has two ends and defines a longitudinal groove therein for receiving the rotational moment transfer element of the shaft, the shaft thereby transferring its rotational moment to the screw element. The groove is configured such that it defines two expansion regions, each expansion region having an axial extent, the groove having side surfaces which diverge with respect to a longitudinal axis of the groove along the axial extent of each expansion region in a direction toward a corresponding one of the two ends of the screw elements, a width of the groove thereby increasing in a direction toward its two ends along each expansion region.

Abstract: In a screw element for the conditioning and/or processing of plastics or elastomers in a screw-type extruding machine having screw shafts drivable to rotate in the same direction and at least one pair of meshing screw elements, each screw element having a land of which the enveloping curve extends radially at a constant distance away from the respective shaft and, in the longitudinal direction, is of linear extension in parallel to the longitudinal axis of the shaft, a radially external screw land section near the housing running parallel to the inside wall of the housing with little play relative to the latter, for the purpose of moderate recirculation without stress points accompanied by strong axial and transverse mixing in a defined volume, it is provided that the enveloping curve encloses a blade land of reduced cross-sectional area referred to the enveloping curve, in that starting from the one axial end of the screw element and the first, in the circumferential direction external, end of the section, n

Abstract: A screw-type extrusion machine has a housing with at least one housing bore, in which a screw shaft is arranged. The housing has outer surfaces, which have a non-constant distance to the wall of the at least one bore. The outer surfaces are provided with heating elements. In order to attain an approximately constant temperature along the circumference of the wall of the at least one bore, heating elements of a different specific heating capacity are arranged sectionally on the outer surfaces of the housing, the heating elements being such formed that the heating temperature at the wall of the at least one bore is approximately constant.

Abstract: A degassification device for a screw extruder which processes plastic material in which the extruder has a hollow housing and an extruder screw rotatable in the housing, the degassification device having a pair of degassification screws disposed adjacent to the extruder screw for rotation about axes parallel to the axes of rotation of the extruder screw. A housing headpiece accommodates the degassification screws and is in communication with the extruder housing such that gas and vapor produced in the extruder housing can flow radially therefrom into the housing headpiece for discharge therefrom. The degassification screws have threads which interengage one another and they are driven in the same direction of rotation. The housing headpiece has adjacent longitudinal bores which overlap one another and respectively receive the degassification screws therein with their threads interengaged with one another.

Abstract: A co-rotating twin-screw kneader has a casing which has two axially parallel bores, defined by the casing wall and which intersect with one another in a region to form gussets in said casing wall adjacent the intersecting region. Two axially parallel shafts which are arranged to be driven in the same direction of rotation are each arranged in a respective one of the bores and multi-flight kneading disks having crests associated with the casing wall are mounted in non-rotary manner on at least part of the length of each shaft. Each kneading disk on one shaft is associated with another disk on the other shaft in a plane perpendicular to the axes of the shafts and the disks are arranged to be moved past one another in a virtually clearance-free manner in the intersecting region of the bores.