A filtering device for removing dirt particles and contaminants from a plastic melt is disclosed. The filtering device includes a housing having a filter chamber, an inlet for feeding plastic melt, an outlet for channeling plastic melt out, and a dirt outlet for discharging dirt particles from the housing. The filtering device also includes a filter element arranged in the filter chamber to retain any dirt particles contained in the stream of melt, and a cleaning unit for cleaning the filter element of dirt particles retained by means of the filter element. The cleaning unit having a cleaning head with a scraper member for detaching dirt particles from the filter element. The scraper member is coupled to a servomechanism to press the scraper member onto the surface of the filter element. The servomechanism has at least one bellows cylinder including a foot section, a head section, a deformable bellows element, and a pressure chamber of variable volume.

A method of forming a polyethylene terephthalate (PET) mixture with talc includes: providing a feed of PET (PET feed); providing a feed of talc (talc feed); mixing the feed of PET with the feed of talc in a mixer at a PET:talc ratio of about 3:1 to about 1:3 to form a PET/talc mixture; and providing the PET/talc mixture as output. A method of forming a Polyethylene Terephthalate (PET) alloy having talc includes: providing a feed of the PET/talc mixture (PET/talc feed); providing a feed of PET (PET feed); mixing the feed of PET with the feed of PET/talc in a mixer to form a PET alloy having from about 1% (w/w) talc to about 50% talc (w/w); and providing the PET alloy as output.

A method of forming a polyethylene terephthalate (PET) mixture with talc includes: providing a feed of PET (PET feed); providing a feed of talc (talc feed); mixing the feed of PET with the feed of talc in a mixer at a PET:talc ratio of about 3:1 to about 1:3 to form a PET/talc mixture; and providing the PET/talc mixture as output. A method of forming a Polyethylene Terephthalate (PET) alloy having talc includes: providing a feed of the PET/talc mixture (PET/talc feed); providing a feed of PET (PET feed); mixing the feed of PET with the feed of PET/talc in a mixer to form a PET alloy having from about 1% (w/w) talc to about 50% talc (w/w); and providing the PET alloy as output.

An extruder is provided with: a screw rotationally driven about the axis by a first motor; a barrel having a screw hole into which the screw is inserted and a de-airing port configured to discharge air inside the screw hole; a filter configured such that a part thereof faces the de-airing port of the barrel; and a filter-driving mechanism configured to move the filter to shift the part of the filter facing the de-airing port.

The invention relates to a filter device for a plastic melt or another highly viscous fluid, comprising a housing with an inlet plate and a discharge plate. At least one spacing element and a screen wheel which can be rotated by a drive device are arranged between the inlet plate and the discharge plate. The inlet plate and the discharge plate are clamped against each other with the inclusion of the spacing element via at least three housing clamping elements. An engagement point of the drive device on the screen wheel is arranged outside of the pretensioning surface. When viewed in the rotational direction, an angle α larger than 110° and smaller than 160° is formed on the screen wheel between a first line that extends between the pretensioning surface centroid on which a resulting frictional force F.sub.R acts and the center of the screen wheel and a second line between the center and the engagement point on which an advancing force Fv acts.

A filter element for filtering a fluid comprises a first clamping ring with an outer ring; a first filter disk; a first inner support plate for supporting the first filter disk and which faces to the outside or to an inner flow channel; a second inner support plate provided with recesses; a second filter disk arranged adjacent the second inner support plate; and a second clamping ring which is connected to the first clamping ring by connecting elements. The filter disks and the inner support plates are arranged inside a housing which is formed by the clamping rings, by at least one outer ring and by outer support plates provided with recesses and covering the filter disks on the outside.

On a rotary screen filtering device for medium to high-viscosity fluids, which comprises a rotary screen mounted for rotation in a housing, which screen has at least one screen element through which fluid can flow, the rotary screen, in the region of its sealing faces and the intermediate plates are fabricated or machined together so that they are of identical height. A gap width compensation layer is then inserted between the inlet plate and the intermediate plate and/or between the outlet plate and the intermediate plate. The package of plates is then pretensioned by means of screw bolts in such a manner that all the plates lie firmly against one another up to a maximum permissible operating pressure. Lubrication gaps of defined width are created between the sealing faces and the opposing inner faces of the inlet and outlet plates.

A method includes feeding a heated polymer additive at a first temperature into a continuous mixer at a first feed rate. The method includes feeding a heated abrasive solid material at a second temperature into the continuous mixer at a second feed rate. The heated abrasive solid material and the heated polymer additive are mixed in the continuous mixer to form a first mixture.

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.

A method of forming a polyethylene terephthalate (PET) mixture with talc includes: providing a feed of PET (PET feed); providing a feed of talc (talc feed); mixing the feed of PET with the feed of talc in a mixer at a PET:talc ratio of about 3:1 to about 1:3 to form a PET/talc mixture; and providing the PET/talc mixture as output. A method of forming a Polyethylene Terephthalate (PET) alloy having talc includes: providing a feed of the PET/talc mixture (PET/talc feed); providing a feed of PET (PET feed); mixing the feed of PET with the feed of PET/talc in a mixer to form a PET alloy having from about 1% (w/w) talc to about 50% talc (w/w); and providing the PET alloy as output.