A torpedo for an extruder comprises: longitudinal member (9) which is provided at the periphery thereof with a plurality of thread portions (12) which protrude outwards and which are spaced apart in the circumferential direction; a plurality of sluice blades (19) which are mounted so as to be movable on the longitudinal member and which are partially engaged in apertures (18) of the longitudinal member, the longitudinal member (9) and the sluice blades (19) being provided with complementary radial guiding surfaces (13, 14, 18) which are in contact with each other; and adjustment means (28) for radially displacing the sluice blades relative to the longitudinal member. The sluice blades extend through the spaces between the thread portions, respectively. The thread portions (12) and the sluice blades (19) are provided with complementary radial guiding surfaces (13, 14, 18).

An extruder (5) for extruding an electric cable has an extrusion screw (7) arranged inside a barrel (6) and making it possible for the polymer to melt gradually in order to form an extrusion composition and for this composition to be transported along the extrusion screw (7). An extrusion head (8) is arranged at a distal end (21) of the extrusion screw (7) and configured to apply the composition around an elongated electrically conductive element. The at least one liquid injection channel (22) is formed through the barrel (6), the at least one injection channel (22) having at least one outlet orifice (30) emerging in a zone of the extrusion screw (7) in which the thermoplastic polymer is at least partially in the solid state.

A method for producing an extruder screw, the method including a. sequentially sliding screw segments onto a tensioned longitudinally extending cylindrical tension rod, the screw segments including: i. radially protruding functional elements configured to feed, mix and/or knead an extrudate, ii. a through bore oriented in a longitudinal direction of the extruder screw (1), and iii. an inner spline extending in the through bore in the longitudinal direction of the extruder screw; b. inserting cylindrical coupling pieces including an outer coupling piece spline into the through bore with positive form locking so that the cylindrical coupling pieces connect adjacent screw segments torque proof; and c. axially supporting the screw segments at a tip of the tension rod and clamping the screw segments against the tip of the tension rod, wherein the inner spline extends over an entire length of the through bore.

The invention relates to a mixing device for a twin-screw extruder, in particular a twin-screw extruder rotating in the opposite direction, comprising a first screw and a second screw, for mixing a melt flow in a screw antechamber, wherein the first screw has an extension in the form of a mixing screw tip connected to the first screw in a fixed manner, and a first melt channel, into which the first screw feeds, is arranged in a flow-connected manner via an elongated slot with a second melt channel, into which the second screw feeds.

The disclosure relates to various measures for increasing the cooling effect on a planetary roller extruder section/module. Those measures include a choke being arranged at an outlet of the planetary roller extruder section or module, a distance between centerlines of adjacent planetary spindles being at least equal to an outer diameter of the planetary spindles, providing a pressurized melt supply, having a cooling section composed of several sections/modules, providing at least one section/module in which a flow, during melt supply is converse to the conveying direction of the extruder, and providing cooling tubes arranged within the central spindle.

The present disclosure relates to devices for extruding plastics, notably mixtures of elastomers which are intended to be used in the manufacture of tires.

A screw element (100) for an extrusion machine is provided. The screw element (100) includes a first section (200) and a second section. The first section (200 has a first core (212) with a plurality of facets (214) connected to each other along splines (216). The facets (214) and splines (216) extend longitudinally along the screw element (100). The facets (214) and splines (216) can be helically-shaped. The first core (212) increases in diameter in a continuous manner along the direction of flow of material. The first and second sections (200, 300) include one or more helically-shaped flights (218,219) wrapped around the longitudinal axis of the screw element (100).

An element for a co-rotating twin screw processor, the element having a lead L and at least one continuous flight helically formed thereon and, wherein the flight transforms at least once from a first non-integer lobe flight into a second non-integer lobe flight in a fraction of the lead L and transforms back to the first non-integer lobe flight in a fraction of the lead L.

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 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.