The invention relates to a mixing and kneading machine for continuous preparation processes, such as for producing granules, extruded profiles, or molded articles, such as polymer granules, polymer extruded profiles, or polymer molded parts, having a feeding and mixing device (12) and a discharge device (14), wherein the feeding and mixing device includes a housing (18), a screw shaft (34), and a connecting element (24), wherein the connecting element is arranged at a front side of the housing and is also connected to the discharge device, wherein a hollow interior is formed in both the housing and the connecting element, and the screw shaft extends, at least sectionally, in the axial direction through the interior of the housing and, at least sectionally, in the axial direction through the interior of the connecting element, and wherein a plurality of kneading elements (40), which extend from the inner circumferential surface of the housing into the interior, are provided in the housing, and wherein kneading elements (40) are also arranged on the inner circumferential surface of the connecting element and extend into the interior of the connecting element, and the discharge device has a degassing device (26).

A method is provided for the co-extrusion of a complex rubber profiled element. The method makes it possible to co-extrude a sublayer in a first material and a tread in a second material with at least one insert in a third material inserted in a discontinuity in the sublayer and in the tread. The method includes: a) discontinuous extrusion of the first material, b) discontinuous first profiling of the first material, c) discontinuous extrusion of the second material onto the first material, d) discontinuous profiling of the first and second materials and extrusion of the third material into each discontinuity, and e) final profiling of the first, second and third materials with a longitudinal groove in the profiled element next to each insert of the third material.

Device and method for dispersing solids, liquids and gases in an extruder, having at least one shaft (1) and one housing (2), wherein at least one disk (4) with recesses is attached to the shaft, which at least one disk co-rotates with the shaft, and a non-co-rotating disk (3) is arranged immediately adjacent to the disk either in a product flow direction or counter to the product flow direction, which non-co-rotating disk likewise has recesses, and wherein the co-rotating disk is connected to the rotating shaft and has a gap (14) with respect to the housing, and the non-co-rotating disk is connected to the housing and has a gap (15) with respect to the rotating core shaft.

Device and method for dispersing solids, liquids and gases in an extruder, having at least one shaft (1) and one housing (2), wherein at least one disk (4) with recesses is attached to the shaft, which at least one disk co-rotates with the shaft, and a non-co-rotating disk (3) is arranged immediately adjacent to the disk either in a product flow direction or counter to the product flow direction, which non-co-rotating disk likewise has recesses, and wherein the co-rotating disk is connected to the rotating shaft and has a gap (14) with respect to the housing, and the non-co-rotating disk is connected to the housing and has a gap (15) with respect to the rotating core shaft.

A method for producing a fused unplasticised polyvinyl chloride (UPVC) article (126) is provided. The method includes feeding an UPVC blend (103) into a co-rotating twin-screw extruder (100). The method further includes melting the UPVC blend (103) and conveying fused UPVC to an outlet (120) of the co-rotating twin-screw extruder (100). The method also includes collecting the fused UPVC from the outlet (120) at a rate of at least 100 kilograms/hour per litre of free volume (124) of the co-rotating twin-screw extruder (100).

The invention relates to a process for removal of volatile components from an olefin polymer, the process carried out in an extruder comprising at least one vacuum degassing zone, said process comprising the steps of: (a) introducing a stream of an olefin polymer into the extruder; (b) extruding the olefin polymer in the extruder at a temperature which is higher than the melting temperature of the olefin polymer but lower than the decomposition temperature of the olefin polymer, thereby producing an olefin polymer melt having reduced amount of volatile components, wherein the process in the extruder has a residence time distribution broadness (σ2) in the range of 800 to 4000 as define by equation (1) wherein: σ2 is the residence time distribution broadness, T is the mean residence time, t is the interval of residence time a fluid element of the olefin polymer spends in the extruder, E(t) is the residence time distribution function, and wherein the process optionally comprises a step (c) where the melt of the olefin polymer is passed through a die zone to a pelletizer for pelletizing the obtained olefin polymer.

σ.sup.2=∫.sub.0.sup.∞(t−τ).sup.2E(t)dt   equation (1)

A Screw for use in a twin-screw assembly of an elastomer mixture extruder with a threaded part with a single-start thread which defines at least three different sectors of the screw. The three sectors have an intake segment to capture the mixture fed from outside to push it downstream along the longitudinal direction, with a cross-section of the through-flow channel between adjacent flanks of the thread which is constant over at least two pitches or a rotation through 720 degrees of the thread. A transition sector which has a cross-section of the through-flow channel variable and smaller than the cross-section of the through-flow channel and is designed to cause an increase of the thrusting pressure acting on the mixture in transit in the longitudinal direction; and a high-pressure sector designed to cause the compression of the mixture to obtain a maximum pressure of the mixture.

A Screw for use in a twin-screw assembly of an elastomer mixture extruder with a threaded part with a single-start thread which defines at least three different sectors of the screw. The three sectors have an intake segment to capture the mixture fed from outside to push it downstream along the longitudinal direction, with a cross-section of the through-flow channel between adjacent flanks of the thread which is constant over at least two pitches or a rotation through 720 degrees of the thread. A transition sector which has a cross-section of the through-flow channel variable and smaller than the cross-section of the through-flow channel and is designed to cause an increase of the thrusting pressure acting on the mixture in transit in the longitudinal direction; and a high-pressure sector designed to cause the compression of the mixture to obtain a maximum pressure of the mixture.

A method of continuously manufacturing a cured membrane includes continuously compounding and mixing a vulcanizable rubber composition in a mixing extruder while continuously removing gasses from the vulcanizable rubber composition during mixing with a vacuum. The vulcanizable rubber composition may be continuously extruded to form an extrudate, which may be continuously calendered to form a green membrane. The green membrane may be continuously cured, such as by a hot air conveyor curing system, to form a cured membrane.

A method of continuously manufacturing a cured membrane includes continuously compounding and mixing a vulcanizable rubber composition in a mixing extruder while continuously removing gasses from the vulcanizable rubber composition during mixing with a vacuum. The vulcanizable rubber composition may be continuously extruded to form an extrudate, which may be continuously calendered to form a green membrane. The green membrane may be continuously cured, such as by a hot air conveyor curing system, to form a cured membrane.