The disclosure discloses a co-rotating dual speed multi-screw extruder and a processing method thereof, the co-rotating dual speed multi-screw extruder enables a first screw and a second screw with the same outer diameter to co-rotate at different speed in a barrel, and the two screws wipe with each other, to achieve self-cleaning in processing; and circular arcs meshed with each other are respectively arranged between root diameters and top diameters of the two screws to form a first step structure and a second step structure, thus breaking an axial symmetry of a cross-sectional contour of the screws, and moreover, the first step structure and the second step structure are periodically meshed in a meshing zone in a staggered manner, so that a flow channel in the meshing zone is changed in a topological way, a strong elongation action and a strong disturbance action are effectively introduced in the meshing zone.

The disclosure discloses a co-rotating dual speed multi-screw extruder and a processing method thereof, the co-rotating dual speed multi-screw extruder enables a first screw and a second screw with the same outer diameter to co-rotate at different speed in a barrel, and the two screws wipe with each other, to achieve self-cleaning in processing; and circular arcs meshed with each other are respectively arranged between root diameters and top diameters of the two screws to form a first step structure and a second step structure, thus breaking an axial symmetry of a cross-sectional contour of the screws, and moreover, the first step structure and the second step structure are periodically meshed in a meshing zone in a staggered manner, so that a flow channel in the meshing zone is changed in a topological way, a strong elongation action and a strong disturbance action are effectively introduced in the meshing zone.

A process for preparing granules is disclosed. The process comprises the steps of feeding the input material for granulation in a processor using one or more powder feeders, introducing steam as a granulation activating agent in the processor, granulating the input material in presence of the steam to form granules, and collecting the granules from a discharge zone of the processor. A co-rotating twin-screw processor for preparing granules is also disclosed.

A screw for a plasticating apparatus has one or more helical flights. A portion of the screw has a plurality of advancing grooves arranged in a noncontinuous helix cut in the screw. The advancing grooves are dimensioned to receive material therein as the material is conveyed through the barrel. The screw has a plurality of noncontinuous cross-cut grooves traversing one or more of the advancing grooves. The cross-cut grooves have a second helix angle greater than the first helix angle and less than ninety degrees; and/or one or more of the cross-cut grooves have a third helix angle of about ninety degrees.

A planetary extruder for producing and processing polymers includes a degassing section. The extruder includes a housing and a bushing arranged therein. The bushing has an internal toothing with a pitch diameter and a root circle. An externally toothed central spindle is arranged within the housing. Planetary spindles rotate about the central spindle between the central spindle and the bushing. A heat transfer fluid is guided through fluid channels which extend helically along an outer surface of the bushing and guide the heat transfer fluid axially. A degassing opening is provided to which a negative pressure is applied for degassing. A minimum radial thickness (t) of the bushing between the root circle of the internal toothing on an inside of the bushing and a bottom of the fluid channels on an outside of the bushing is selected based on the pitch diameter (d) of the internal toothing.

An mixing section for an extrusion screw has an inlet end and an outlet end as well as alternating wiping lands and barrier lands. The wiping lands have a greater helix angle than the barrier lands. The wiping lands and the barrier lands define inlet channels which narrow toward the outlet end and outlet channels which widen toward the outlet end. A helical pattern of mixing channels is cut into the wiping lands and the barrier lands. The mixing channels may be oriented generally at approximately right angles to the wiping lands and the barrier lands. A portion of the extrudate encounters the inside wall surfaces of the mixing channels and changes direction which improves the mixing of the extrudate.

A planetary roller extruder section forms a feed part of an extruder. The planetary roller extruder has an internally toothed housing and an externally toothed central spindle disposed centrally within and at a distance from the housing. Planetary spindles are arranged to rotate in a void between the central spindle and the housing. Each planetary spindle has an external toothing meshing with both the housing and the central spindle. At least one planetary spindle has two axially spaced areas with less than a full set of teeth. Those axially spaced areas include a first area having a first number of teeth and a second area having a second number of teeth. The second number of teeth is less than a full set of teeth and more than the first number of teeth.

In a multi-shaft extruder for the processing of free-flowing material having a barrel and a plurality of co-rotating, tightly intermeshing conveyor shafts (1 to 3) arranged in parallel which have at least two flights and are each guided in a bore (1 to 3) in the barrel, each conveyor shaft (1 to 3) is spaced with the ridge (O) of one of its flights from the bore wall (1, 2, 3) by a clearance over at least part of the processing length of the extruder, whereas a gap is formed between the ridge (a, b, c) of another of its flights and the bore wall (1, 2, 3). The conveyor shafts (1 to 3) are arranged in an offset manner relative to each other at an angle such that, at least in one rotational position, the conveyor shaft (2) arranged between two conveyor shafts (1 to 3) is coatable with the free-flowing material on its flanks (A, B) between its ridges (b, O) by means of the gap-forming ridges (a, c) of the two adjacent conveyor shafts (1 and 3), with the said flanks (A, B) being cleanable again from the free-flowing material by means of the ridges (O) of the two adjacent conveyor shafts (1 and 2) spaced from the bore wall (1, 2, 3) by a clearance in at least one further rotational position of the conveyor shaft.

In a multi-shaft extruder for the processing of free-flowing material having a barrel and a plurality of co-rotating, tightly intermeshing conveyor shafts (1 to 3) arranged in parallel which have at least two flights and are each guided in a bore (1 to 3) in the barrel, each conveyor shaft (1 to 3) is spaced with the ridge (O) of one of its flights from the bore wall (1, 2, 3) by a clearance over at least part of the processing length of the extruder, whereas a gap is formed between the ridge (a, b, c) of another of its flights and the bore wall (1, 2, 3). The conveyor shafts (1 to 3) are arranged in an offset manner relative to each other at an angle such that, at least in one rotational position, the conveyor shaft (2) arranged between two conveyor shafts (1 to 3) is coatable with the free-flowing material on its flanks (A, B) between its ridges (b, O) by means of the gap-forming ridges (a, c) of the two adjacent conveyor shafts (1 and 3), with the said flanks (A, B) being cleanable again from the free-flowing material by means of the ridges (O) of the two adjacent conveyor shafts (1 and 2) spaced from the bore wall (1, 2, 3) by a clearance in at least one further rotational position of the conveyor shaft.

A single-screw extruder (100), and a method. The extruder (100) comprisesa cylindrical rotor member (1) having diameter (D) and length (L) and comprising a feeding zone (14), the rotor member (1) arranged in a barrel (2), the cylindrical surface of the rotor member (1) carrying cavity/cavities and/or projection(s) (5) arranged in helically extending rows, the helically extending row(s) of the rotor member (1) having a pitch (P) and depth (d) in the feeding zone (14) of the rotor member, and the extruder (100) further comprising a drive system (4) for the rotation of the rotor member (1) in the barrel (2). The relation of the depth (d) to the diameter (D) of the rotor member, i.e. d:D, is not more than 1:20, and the relation of the pitch (P) of the rotor member to the diameter (D) of the rotor member, i.e. P:D, is not more than 1:4.