An extruder screw for a multi-screw extruder, having an intake and metering section. A rotor body has an enlarged diameter relative to the intake and metering section and has a plurality of satellite screws positioned on the outer periphery of the rotor body at least over part of the length thereof. A cone and an adjoining drive zone are formed between the intake and metering section and the rotor body, in which drive zone the satellite screws each engage via a drive pinion in an external toothing on the rotor body or in an internal toothing on a stator ring or in the inner wall of an extruder housing. At least one peripherally closed flow channel is formed, which flow channel extends from an inlet opening on the cone to an outlet opening located downstream of the drive pinions in the direction of flow.

The invention relates to a process for the production of articles, exemplarily a plastic article, by means of an extruder (1) to which a first plastic composition of a first main component and at least one associated minor component is supplied from a first group of dosing stations (21, 24). According to the invention, during the production time of a first production order there is prepared a second group of dosing stations (31, 33) at the extruder for a second production order for which a second plastic composition of a second main component and at least one associated minor component that is different from the first plastic composition has to be supplied to the extruder. After completion of the first production order it is reset to the second production order by terminating the supply of the first plastic composition by closing a first shut-off device (8) and starting the supply of the second plastic composition by opening a second shut-off device (8′).

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.

A device for producing a dyed plastic melt and an undyed plastic melt includes a multi-shaft screw extruder, a first metering installation, a second metering installation, and a control installation for selecting between a first operating mode for producing the dyed plastic melt and a second operating mode for producing the undyed plastic melt. The first metering installation serves for feeding an undyed plastic material through a first infeed opening into a housing of the multi-shaft screw extruder, and the second metering installation serves for feeding at least one color granulate through a second infeed opening into the housing. The plastic material is fed exclusively by way of the first infeed opening such that residual color granulate or dyeing agent contained therein, respectively, which is still located in the second metering installation or in the region of the second infeed opening does not contaminate the undyed plastic melt.

A mixing and extrusion machine (10) for the manufacture of rubber mixtures has a mixer with a converging conical twin screw (12) with a fixed frame (14) that supports sleeves (16). Two screws (18), being mounted at an angle, are mounted in the mixer (12) so as to move in translational movement between an opening (22) arranged upstream and an outlet (25) arranged downstream of the sleeves, so that the thread tips of each screw contact tangentially the surfaces of the opposite screw so that the screws remain substantially in contact with each other when the screws rotate at an angle and at a center distance that facilitates self-cleaning. The screw threads maintain tangential contact with the inner surfaces of the sleeves, thus preventing the retention of mixing material on these surfaces.

A connecting device for connecting a screw machine to a gear mechanism comprises a housing which in regions delimits an interior. The interior serves for the arrangement of at least one shaft connection between at least one gear shaft and at least one screw shaft. The connecting device comprises at least one cleaning element for cleaning contaminants from the interior. The connecting device allows simple, efficient and reliable cleaning of contaminants from the interior.

Mixing performance of resin material in the rotational direction of the screw is enhanced. Kneading disc 7 is fitted onto rotatable shaft 3 and is arranged in cylinder 2. Outer circumferential surface 8 of kneading disc 7 of the present invention that faces cylinder 2 has band portion 9 that extends between both ends 7a, 7b of kneading disc 7 in axial direction X of shaft 3 and that forms a minimum gap with cylinder 2. Band portion 9 includes at least one bent part 10.

A method and a facility produce polylactide (PLA) by polymerization, in which a lactide mixture is mixed with at least one catalyst, is introduced into a modular planetary roller extruder and the finished PLA is then removed. The lactide mixture continuously passes through segments of the extruder. The course of the reaction is measured and controlled in the segments in a targeted manner such that the temperature can be set by heating and/or cooling. The pressure can be variably set depending on pressure values to be checked by a controllable gas extraction and/or a controllable extruder speed and/or static variability of the planetary rollers and/or a variable metering speed of the lactide mixture and/or a variable mixing ratio of the lactide mixture. Flammable gas is removed in an explosion-protected zone in a partial region of the extruder. Additives are introduced into the extruder during the rolling process.

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.

A barrel block for a twin-screw extruder constitutes a barrel including a cylinder and has joints at both ends. A first joint includes a first inner joint face on a peripheral edge of a first hole of an insertion hole for screws, and includes a first flank face and a first outer joint face on an outer periphery of the first inner joint face. The first outer joint face is located in the outer periphery of a plurality of first bolt holes. The first outer joint face is more recessed toward a second block end face than the first inner joint face.