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.

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30), wherein between the melt inlet (20) and the melt outlet (30) at least a melt guidance means (40) is assembled for a rearrangement of molten material (200) from the centre (22) of the melt inlet (20) to the edge (34) of the melt outlet (30) and for a rearrangement of molten material (200) from the edge (24) of the melt inlet (20) into the centre (32) of the melt outlet (30).

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30) wherein between the melt inlet (20) and the melt outlet (30) at least one melt guidance means (40) is assembled for a rearrangement of the molten material (200) from the center (22) of the melt inlet (20) to the edge (34) of the melt outlet (30) and for rearrangement of the molten material (200) from the edge (24) of the melt inlet (20) into the center (32) of the melt outlet (30).

Disclosed is a system and a method for marking a continuously produced sheet of elastomeric material to identify sheet batches associated with a respective stock of raw extrusion material in a longitudinal direction of the continuously produced sheet. The apparatus includes one or more marking tools for providing the continuously produced sheet with a series of batch markings which are indicative of the respective sheet batch and for providing a start or end marking indicating the start or end, respectively, of a respective sheet batch.

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30), wherein between the melt inlet (20) and the melt outlet (30) at least one melt guiding means (40) is assembled for a rearrangement of molten material (200) from the centre (22) of the melt inlet (20) to the edge (34) of the melt outlet (30) and for a rearrangement of molten material (200) from the edge (24) of the melt inlet (20) into the centre (32) of the melt outlet (30).

Methods for extrusion of polyolefins (110) that utilize melt temperature to control molecular weight and also reduce gels. Disclosed herein is an example method for controlling polymer chain scission in an extrusion system (100), comprising: melting a polyolefin resin (110) in extruder (102) at a first melt temperature to form a first melt (112); passing the first melt (112) through a screen pack (106); forming the first melt 112) into a first polyolefin product (116, 118); melting additional polyolefin resin (110) of the same grade in the extruder (102) at a second melt temperature to form a second melt (112), wherein the second melt temperature differs from the first melt temperature by 5 C. or more to control chain scission in the extruder (102); passing the second melt (112) through the screen pack (106); and forming the second melt (112) into a second polyolefin product (116, 118).

The invention relates to a method for automatically regulating the size of a nozzle discharge slot of a nozzle assembly, wherein the nozzle assembly comprises a first and a second nozzle lip and a nozzle discharge slot arranged between the nozzle lips for setting in a controlled manner a thickness profile of a conveyable melt. A plurality of adjusting elements, in particular a plurality of adjusting pins, coupled to a respective thermoelement, is arranged on the first nozzle lip, the thermoelements being controllable by the regulation in such a way that the slot can be adjusted by the action of a mechanical force from the respective adjusting element on the first nozzle lip, as a result of the expansion or contraction of the thermoelements. At an initial operation of the nozzle assembly for conveying the melt, the adjusting elements for subsequent regulation of the slot size are set uniquely free from play as the initial setting. The invention further relates to a control and/or regulation system.

Provided is a production apparatus capable of producing a flexible tube whose hardness is naturally varied along the length direction thereof. This mixing valve includes: a first valve configured to distribute a first resin to a resin supply path and a resin discharge path; and a second valve configured to distribute a second resin to the resin supply path and the resin discharge path. In the mixing valve, the mixing proportion between the first resin and the second resin is increased or decreased in association with molding of the flexible tube, by changing a distribution ratio of the first resin in the first valve and a distribution ratio of the second resin in the second valve while keeping constant the total of the supply mounts of the first resin and the second resin supplied to a die.

A process for manufacturing a diesel tank or filler pipe by an extrusion-blow molding machine configured to manufacture a gasoline tank or filler pipe. The extrusion-blow molding machine includes a coextrusion head including at least one extruder configured to provide during a first period of time a first material that is a barrier to liquids and/or gases, such that during the first period of time the coextrusion head produces a first multilayer parison from which the gasoline tank or filler pipe can be manufactured. The extruder is further configured to provide during a second period of time a second material distinct from the first material, such that during the second period of time the coextrusion head produces a second multilayer parison from which the diesel tank or filler pipe can be manufactured.

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.