An extruder includes a screw for extruder provided with a screw element for kneading a raw material, and a barrel including a cylinder portion in which the screw is inserted so as to be rotatable. A plurality of screw elements identical with the screw element are provided in a longitudinal direction of the screw under a certain rule. The barrel is integrated by combining a plurality of barrel blocks blocked. Each of the plurality of barrel blocks is configured in accordance with a length of the screw element provided in the longitudinal direction of the screw.

The invention relates to mixing elements having an increased number of base geometry periods per longitudinal section and an improved dispersing effect for multi-shaft screw extruders comprising screw shafts that co-rotate in pairs. The mixing elements have clearances that are configured according to the method of spatial equidistants or according to the method of longitudinal equidistants. The invention further relates to the use of the mixing elements in multi-shaft screw extruders, a corresponding screw extruder comprising the mixing elements, and a method for extruding plastic masses.

The kneading apparatus 1 includes a casing 2, a pair of elongated screws 4a, 4b rotatably provided in the casing 2. The screws 4a, 4b are arranged parallel and horizontally with respect to one another. The casing 2 has a main body 20 and a screw container 3 provided in the casing 2. The screw container 3 defines a kneading section 30 therein. The screw 4a includes a screw axis 41 having an outer periphery, a first screw member 42 provided on the outer periphery of the screw axis 41 and a kneading member 43 provided on the outer periphery of the screw axis 41. The first screw member 42 and kneading member 43 are provided in the kneading section 30. The screw 4a, the first screw member 42 and the kneading member 43 respectively have core portions 411, 412, 413 having a surface and outer layers 45 respectively provided on the surfaces of the core portions 411, 412, 413. The screw container 3 and the outer layers 45 are constituted of a nonmetallic material.

In a method of manufacturing a transparent resin composition, a molten resin mixture is produced by supplying polycarbonate resin and acrylic resin continuously to a twin-screw extruder. The molten resin mixture is supplied to a single-screw extruder including a screw in which a shear processing portion is provided. Further, a transparent resin composition is produced continuously by kneading the molten resin mixture in the shear processing portion which rotates at between 500 and 4000 rpm.

A continuous kneading device (1) includes a pair of kneading rotors (3), being capable of increasing mesh between the kneading rotors (3) while suppressing a kneading load applied to the kneading rotors (3). The continuous kneading device (1) includes a barrel (2) and a pair of kneading rotors (3) housed in the barrel (2) and rotating in mesh in directions different from each other. Each kneading rotor (3) includes a plurality of kneading flights (11, 15) for kneading a material supplied into the barrel (2). The kneading flights (11, 15) and respective portions of the barrel (2) housing the kneading flights (11, 15) respectively configure a plurality of kneading sections aligned axially of the kneading rotors (3). The material is fed axially from the upstream kneading section to the downstream kneading section to be sequentially kneaded. The kneading flight (15) constituting the downstream kneading section has a rotational outer diameter (D2) larger than a rotational outer diameter (D1) of the kneading flight (11) constituting the upstream kneading section.

A process for producing a biopolymer nanoparticles product is disclosed. In this process, biopolymer feedstock and a plasticizer are fed to a feed zone of an extruder having a screw configuration in which the feedstock is process using shear forces in the extruder, and a crosslinking agent is added to the extruder downstream of the feed zone. The biopolymer feedstock and plasticizer are preferably added separately to the feed zone. The screw configuration may include two or more steam seal sections. Shear forces in a first section of the extruder may be greater than shear forces in an adjacent second section of the extruder downstream of the first section. In a post reaction section located after a point in which the crosslinking reaction has been completed, water may be added to improve die performance.

The invention relates to mixing elements that have a larger number of basic geometric periods per section and an improved dispersing effect for multi-shaft screw extruders comprising screw shafts that co-rotate in pairs. The invention further relates to the use of the mixing elements in multi-shaft screw extruders, a corresponding screw extruder comprising the mixing elements, and a method for extruding kneadable materials.

An extruder screw includes a screw main body, conveyance portions, barrier portions, and paths. The raw materials, the conveyance of which is limited by the barrier portions, flow in from the entrance. The raw materials flowing in from the entrance flow through the paths in an opposite direction to a conveyance direction of the conveyance portions. The exit is opened in the outer circumferential surface of the screw main body at a position on an upstream side in the conveyance direction in the conveyance portions in which the entrance is opened.

A conveyance portion, a barrier portion, and a path are provided at places of a portion of a screw main body in which a kneading portion is provided. In at least one of the places, an entrance is opened to cause raw materials, conveyance of which is limited by a barrier portion to increase pressure on the raw materials, to flow in. The raw materials flowing in from the entrance flow through the path in the opposite direction to a conveyance direction of the conveyance portion. An exit is opened in an outer circumferential surface of the screw main body at a position outside the conveyance portion in which the entrance is opened.

According to one embodiment, an extruder screw includes a screw body. The screw body is rotated about an axis parallel to a direction of conveyance of a raw material. A conveyance portion having a flight is provided on the outer peripheral surface of the screw body. The flight is configured to convey the raw material along the axis of the screw body when the screw body is rotated. A passage for permitting the raw material fed by the flight to pass therethrough to the outer peripheral surface of the screw body is provided in the screw body in a position deviated from the axis of the screw body.