Abstract: A feeding screw machine for feeding a processing screw machine comprises a housing with at least two housing bores formed therein and screw shafts rotatably arranged in the at least two housing bores. The at least two housing bores and the at least two screw shafts define a free volume in a respective cross-sectional plane, which decreases monotonically at least in some regions for continuous compression of a material in a conveying direction. This enables an improved supply of material with a low bulk density.

Abstract: A filter unit for an extruder assembly comprises a support body with a hollow cylindrical wall section and a base section connected thereto, wherein the support body has a central longitudinal axis and delimits an inner space, wherein the hollow cylindrical wall section has a plurality of through openings opening into the inner space and forms an outlet opening for a molten plastic opposite the base section; and a displacement element for displacing the molten plastic which has entered the inner space, in particular via the through openings, substantially in the direction of the central longitudinal axis, wherein the displacement element and the support body are configured and/or produced in one piece, as well as filter arrangement with a plurality of such filter units, filter changing device with at least two filter arrangements and method for producing such a filter unit.

Abstract: 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.

Abstract: A housing cleaning device for cleaning a housing of a screw machine comprises a support unit displaceable relative to the housing, and at least one housing cleaning unit arranged at the support unit, for cleaning an inner wall of the housing, wherein the at least one housing cleaning unit can be reversibly inserted into the housing. An associated shaft cleaning device for cleaning at least one treatment element shaft of the screw machine comprises a cleaning chamber, in which the at least one treatment element shaft can be arranged, and at least one shaft cleaning unit arranged in the cleaning chamber.

Abstract: A device for producing dyed plastic granulate and undyed plastic granulate includes a multi-shaft screw extruder and an underwater pelletizing installation. A granulate changeover unit which separates the dyed plastic granulate from the undyed plastic granulate is disposed in a conveying direction downstream of the underwater pelletizing installation. The dyed plastic granulate is separated from the pelletizing water via a first separator installation, and the undyed plastic granulate is separated from the pelletizing water via a second separator installation. The separator installations are disposed so as to be mutually parallel. The device enables a simple, flexible and economical selective production of the dyed plastic granulate and the undyed plastic granulate.

Abstract: A starting-valve throttle device has a housing having a housing recess which is configured therein and in which a switching member is repositionable between an evacuation position and a delivery position. The switching member in the evacuation position configures an evacuation duct which connects an entry duct to an evacuation opening. The switching member in the delivery position configures a passage duct which connects the entry duct to a delivery duct. A throttle member is disposed in the passage duct so as to be repositionable relative to the switching member. On account thereof, a melt flowing through the passage duct is capable of being throttled in a desired manner. The starting-valve throttle device is constructed so as to be simple, compact and reliable. The operation of the starting-valve throttle device and an associated screw extruder is simple and energy-efficient.

Abstract: 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 dyeing agent through a second infeed opening into the housing. In order for the undyed plastic melt to be produced, the plastic material is fed exclusively via the first infeed opening such that residual dyeing agent 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.

Abstract: A starting-valve throttle device has a housing having a housing recess which is configured therein and in which a switching member is repositionable between an evacuation position and a delivery position. The switching member in the evacuation position configures an evacuation duct which connects an entry duct to an evacuation opening. The switching member in the delivery position configures a passage duct which connects the entry duct to a delivery duct. A throttle member is disposed in the passage duct so as to be repositionable relative to the switching member. On account thereof, a melt flowing through the passage duct is capable of being throttled in a desired manner The starting-valve throttle device is constructed so as to be simple, compact and reliable. The operation of the starting-valve throttle device and an associated screw extruder is simple and energy-efficient.

Abstract: A device for producing dyed plastic granulate and undyed plastic granulate includes a multi-shaft screw extruder and an underwater pelletizing installation. A granulate changeover unit which separates the dyed plastic granulate from the undyed plastic granulate is disposed in a conveying direction downstream of the underwater pelletizing installation. The dyed plastic granulate is separated from the pelletizing water via a first separator installation, and the undyed plastic granulate is separated from the pelletizing water via a second separator installation. The separator installations are disposed so as to be mutually parallel. The device enables a simple, flexible and economical selective production of the dyed plastic granulate and the undyed plastic granulate.

Abstract: 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.