A multi-shaft preparation unit for plastic melts, having an extruder housing with an enclosed treatment chamber in its interior, and at least one rotor body shaft mounted rotatably in the treatment chamber and a sealing and guiding body with multiple recesses, in each of which a satellite screw is mounted. The multi-shaft preparation unit has a drive unit in which a gearing unit is arranged outside the extruder housing between a drive motor and the treatment chamber and is connected to the drive shaft sections of the rotor body shaft and of the satellite screws which lead out of the treatment chamber of the extruder housing. A separating device for decoupling a flow of fluid and/or heat emanating from the treatment chamber is provided between the extruder housing and the gearing unit, through which the drive shaft ends of the rotor body shaft and of the satellite screws pass.

A three-dimensional (3D) drawing pen can include a housing that has a port that permits insertion of a strand of material into the housing, an actuator for controlling a movement of the strand, and a nozzle assembly configured to permit the strand to be extruded out of the 3D drawing pen in a form that retains its shape against gravity in free space to draw a 3D object.

An extruder according to an embodiment includes: a screw configured to rotate around a rotation axis extending in one direction; a cylindrical cylinder extending in the one direction, the cylinder being configured to house the screw; a drive unit disposed at one end of the cylinder, the drive unit being configured to rotate the screw; a die disposed at the other end of the cylinder, the die being configured to discharge a raw material kneaded by the rotation of the screw a as a strand; an adjustment unit disposed between the cylinder and the die, the adjustment unit being configured to adjust a flow-velocity distribution of the raw material flowing into the die; and a detection unit configured to detect a discharge amount of the strand discharged from the die.

An apparatus including a three-dimensional (3D) drawing pen can permit a user to draw in free space to form a 3D object. The 3D drawing pen can include a housing, an actuator, and a nozzle assembly. The housing is configured to receive material therein and fit in a user's hand. The actuator is coupled to the housing and is configured to control a movement of the material. The nozzle assembly is configured to permit the material to be extruded to permit the user to form the three-dimensional object.

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 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.

A cylinder for a plastics-processing machine is provided, comprising at least two hollow-cylindrical bodies. At least one portion of at least one hollow-cylindrical body is provided with an inner coating, particularly a wear-protection layer, and can be attached to the other hollow-cylindrical body, the one hollow-cylindrical body being attachable to the other hollow-cylindrical body in a plurality of different positions. A device is further provided for processing a material and a method is also provided for operating an extruder.

An extruder assembly has a frame with upstream and downstream ends. A barrel assembly on the frame has a passage. At least one material advancing component resides at least partially within the passage and is configured to be turned around an operating axis to thereby cause material to be conveyed from a passage inlet to a passage outlet. A drive assembly turns the at least one material advancing component around its operating axis and has a motor on the frame situated so that at least a part of the motor is in lengthwise overlapping relationship with the barrel assembly. The drive assembly is configured to turn the one material advancing component around its operating axis at a speed of at least 300 rpm.

A three-dimensional (3D) drawing pen can include a housing that has a port that permits insertion of a strand of material into the housing. The strand can be moved through the housing toward a nozzle assembly configured to permit the strand to be extruded out of the 3D drawing pen in a form that retains its shape against gravity in free space to draw a 3D object.

A twin-screw extruder is provided in which screws have different rotational speeds depending on the process of treating the raw material and in which degradation of the raw material is less likely to occur.

Twin-screw extruder 1 has two screws 3, 5 that extend in parallel to each other. Each screw 3, 5 has cylindrical upstream screw 31 and downstream screw 35, wherein upstream screw 31 has shaft hole 315 that extends in longitudinal direction X and screw flight 316 on an outer circumferential surface thereof, and downstream screw 35 includes large diameter portion 353 having screw flight 357 on an outer circumferential surface thereof and small diameter shaft portion 351 that has a smaller diameter than large diameter portion 353, wherein small diameter shaft portion 351 of downstream screw 35 is inserted into shaft hole 315 of upstream screw 31. Upstream screw 31 and downstream screw 35 can be independently rotated. Twin-screw extruder 1 further includes upstream rotating mechanism 84 that rotates upstream screws 31 of two screws 3, 5, and downstream rotating mechanism 83 that rotates downstream screws 35 of two screws 3, 5.