A screw extruder which extrudes a kneaded material includes a screw having a helical flight provided on an outer peripheral surface of a shaft portion thereof, and a chamber housing the screw. In the screw extruder, a flight thickening portion is provided at a part which is a tip portion of the flight and is on the reverse side of a rotation direction of the flight.

A method and apparatus for thermolysing organic material. The method comprises steps of: A) feeding the material in a single-screw extruder (100), the extruder comprising a 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, wherein 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, B) heating the material in the single-screw extruder (100) to a flowable state, and C) thermolysing the material.

A method and apparatus for thermolysing organic material. The method comprises steps of: A) feeding the material in a single-screw extruder (100), the extruder comprising a 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, wherein 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, B) heating the material in the single-screw extruder (100) to a flowable state, and C) thermolysing the material.

The present disclosure relates to a process for preparing granules from an input material or a powder material. The process comprises feeding the input material for granulation in the 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 optionally collecting the granules from a discharge zone of the processor, wherein feed rate of the steam into the processor is determined based on feed rate of the input material into the processor. A co-rotating twin-screw processor for preparing granules is also discl

The present invention relates to an apparatus and method for processing of waste and in particular processing involving a volumetric reduction of waste materials. There is an apparatus for processing waste material comprising a compaction compartment for receipt of waste material, the compaction compartment have a screw vane for processing waste material through the compaction compartment and a waste material outlet. In one aspect the apparatus comprises a heating zone including an arrangement for heating the waste material received from the waste outlet, the apparatus further comprising a cooling zone including a cooling arrangement for cooling the waste material received from the heating zone. In another aspect, at least one of the screw vane or wall comprises one or more ports therein for transfer of liquid from the waste material, the one or more ports having a port inlet and a port outlet, wherein the area of the opening defined by the port inlet is different to the area of the opening defined by the port outlet. In a further aspect, a heating zone for receiving waste material from the waste material outlet is provided where the heating zone includes an arrangement for heating the waste material in the heating zone, and a blocking element for impeding movement of waste material from the heating zone.

A method is disclosed for manufacturing a plastic optical fiber composed of a plurality of layers including a core and a cladding, which includes forming at least one layer formed of the plurality of layers by melt extrusion molding of a material resin using a melt extrusion unit including an extrusion screw, wherein a pellet of the material resin is fed to the melt extrusion unit, and a relation expressed by the following inequality (I) is satisfied by a flight height H.sub.f (mm) of the extrusion screw in a feed zone L.sub.f of the melt extrusion unit and a maximum dimension L.sub.max (mm) of the pellet to be fed: 0H.sub.fL.sub.max3 (I); and a volume V (mm.sup.3) of the pellet satisfies the following inequality (II): 4<V<25. The manufacturing method is suitable for further improvement of the quality of plastic optical fibers.

An extruder (20) is specifically designed for the production of animal feed products (e.g., aquatic feeds) containing substantial quantities of low-cost fibrous materials, such as rice byproducts, at high production rates. The extruder (20) includes an elongated barrel (22) with a screw assembly (24) within the barrel and an endmost extrusion die assembly (34). The screw assembly (24) includes an inlet screw assembly (42) and a processing screw assembly (44). The assembly (44) includes screw components (50-56) of differential pitch to present a long pitch inlet section (64) and a tight pitch discharge section (68). Materials passing through the screw assembly (24) are successively subjected to high levels of steam injection (STE) followed by high levels of friction and shear (SME), so that the STE/SME ratio is at least about 6/1.

In a method and an apparatus for increasing the intrinsic viscosity of a polycondensate melt at negative pressure, the melt enters a chamber, in which a negative pressure of less than 20 mbar prevails, through a perforated plate or a screen having openings with a diameter of less than 0.5 mm. The melt passes through this chamber in free fall in thin threads and remains in a reservoir beneath the chamber for at least one minute. The melt is moved constantly in the reservoir, and discharged from the reservoir, by a helical mixing and discharge part.

A screw has a spiral blade for extruding and kneading a high-silica plastic elastomer containing not less than 100 phr of silica. The screw has a first section located on the most downstream side in the extrusion direction and provided with a barrier extending between the adjacent spiral blade threads, while inclining with respect to the screw axial direction. The length of the barrier is 1.5 to 3.0 times the lead length of the spiral blade in the first section. The height of the barrier is 2 to 10 mm lower than the height of the spiral blade. The barrier thickness is 0.9 to 3.0 times the height difference between the spiral blade and barrier.

A screw has a spiral blade for extruding and kneading a high-silica plastic elastomer containing not less than 100 phr of silica. The screw has a first section located on the most downstream side in the extrusion direction and provided with a barrier extending between the adjacent spiral blade threads, while inclining with respect to the screw axial direction. The length of the barrier is 1.5 to 3.0 times the lead length of the spiral blade in the first section. The height of the barrier is 2 to 10 mm lower than the height of the spiral blade. The barrier thickness is 0.9 to 3.0 times the height difference between the spiral blade and barrier.