For the production of polymers in which there are fillers with particle sizes below 10 μm incorporated and homogeneously distributed, a polymer starting material is input into a twin-screw extruder and is melted there to give a melt. In a conveying and mixing section, a suspension, which is formed of the fillers and of a carrier liquid, is injected into the melt. The melt viscosity is reduced by injection of the carrier liquid in the conveying and mixing section in that a cleavable polycondensate is used as polymer and low-molecular-weight cleavage product arising during the polycondensation is used as carrier liquid, and therefore the molten polymer is at least to some extent depolymerized within the conveying and mixing section. That the mixture, which is formed of the melt whose viscosity is reduced by cleavage, of the remainder of the carrier liquid and of the fillers, is homogenized.

A system comprising: (1) a grinding unit configured to receive and grind recycled PET bottles into a group of polymer flakes comprising up to about ten percent colored polymer flakes and balance substantially clear polymer flakes; (2) a washing unit configured to wash the group of polymer flakes; and (3) an extruder configured to extrude material in a plurality of different extrusion streams. The extruder may be further configured to: (1) receive a concentrate-polymer mixture comprising a mixture of the polymer flakes and a color concentrate; (2) melt the concentrate-polymer mixture to produce a polymer melt; (3) reduce a pressure within the extruder; and (4) pass the polymer melt through the extruder so that the polymer melt is divided into the plurality of extrusion streams. The system may then filter the polymer melt through at least one filter and form the polymer melt into bulked continuous carpet filament.

A method of manufacturing bulked continuous carpet filament which, in various embodiments, comprises: (A) grinding recycled PET bottles into a group of flakes; (B) washing the flakes; (C) identifying and removing impurities, including impure flakes, from the group of flakes; (D) adding one or more color concentrates to the flakes; (E) passing the group of flakes through an extrusion system while maintaining the pressure within the extrusion system below about 25 millibars; (F) passing the resulting polymer melt through at least one filter having a micron rating of less than about 50 microns; and (G) forming the recycled polymer into bulked continuous carpet filament that consists essentially of recycled PET.

An extrusion system including an edge encapsulation block is disclosed. The edge encapsulation block includes a housing that defines a central extrusion channel having an inlet for receiving a central material and an outlet for emitting an encapsulated material that includes the central material and an edge material, and an edge encapsulation channel for receiving the edge material. The encapsulation block also includes an edge blocker that includes an edge actuator at a first end of the edge blocker and an edge block at a second end of the edge blocker that is opposite the first end. Actuation of the edge actuator causes the edge block to translate from a first position to a second position spaced from the first position along an axis that extends through the central extrusion channel.

An extrusion device including at least one extruder having a screw cylinder, a screw shaft rotatably supported in the screw cylinder and an extruder outlet, an injection mould having an outlet nozzle determining the cross-sectional contour of the extruder, and an extrusion head arranged between the extruder outlet of the at least one extruder and the outlet nozzle of the injection mould, wherein at least one perforated plate arranged in the extruder head is provided, which has a plurality of passage openings, wherein the passage openings are designed to dam up extrusion material conveyed from the at least one extruder through the passage openings of the perforated plate differently into at least one first region of the perforated plate and at least one second region of the perforated plate, in such a way that the extrusion material is partly diverted from its preferential direction within a central section of the perforated plate, specifically increasingly into at least one edge section of the perforated plate.

An extrusion die includes a plurality of studs, a tuning assembly and a restrictor member. The tuning assembly comprises a wedge member, first and second adjustment members, and an adjustment control having a rotatable single point adjustment member. The wedge member is coupled to first ends of the studs and includes a first and second plurality of channels within. The first and second adjustment members have a plurality of protrusions, each of which is positioned within a respective one of the first and second plurality of channels. The restrictor member extends in the longitudinal direction and is coupled to second ends of the studs. Rotation of the single point adjustment causes each of the protrusions to move within each respective channel forcing the wedge member, the studs, and the restrictor member to move in a direction that is substantially perpendicular to the longitudinal direction.

An extrusion die is provided with an adjustable end seal assembly. The extrusion die includes a die body, and the adjustable end seal assembly includes an end seal device and a wedge mechanism. The adjustable end seal assembly has an engaged configuration and a disengaged configuration. When in the engaged configuration, the adjustable end seal assembly is held forcibly against the die body. When in the disengaged configuration, the adjustable end seal assembly is either spaced apart from the die body or held against the die body with less force than when in the engaged configuration. Methods of operating such an extrusion die are also provided.

Methods for extrusion of polyolefins (112) that control specific energy input to the extruder (102) for gel reduction. Disclosed herein is an example method for forming plastic products (120, 208) with reduced gels, comprising: melting a polyolefin resin (112) in extruder (102) to form a melt; adjusting specific energy input in the extruder (102) to reduce gels in the melt; and forming the melt into a polyolefin product (120, 208). Disclosed herein is also an example method for forming plastic products (120, 20) with reduced gels, comprising: melting a polyolefin resin in extruder (102) to form a melt; selecting a throttle valve (104) position for gel reduction; setting the throttle valve (104) at the selected throttle valve (104) position to restrict flow of the melt out of the extruder (102); and forming the melt into a polyolefin product (120, 208).

A multi-shaft kneading machine includes a channel and two screws rotatable around first axes of rotation. A pair of gate rods sandwich the two screws and are rotatable around second axes of rotation. Each of the pair of gate rods has two recess parts that form respective spaces through which the two screws penetrate. Each of the pair of gate rods has a first contact surface, which comes into surface contact with a screw when a gate rod is rotated to a minimum degree-of-opening position. Large diameter parts are fitted into the groove of the cylinder, and a small diameter part have a radius of curvature equal to half a distance between two second axes of rotation and smaller than a radius of curvature of the large diameter parts. The small diameter parts of the pair of gate rods are in contact with each other.

The invention relates to an extruder system for degassing a mixture (5), comprising a first extruder (1), a second extruder (2) arranged downstream of the first extruder (1) and a transfer zone (6) formed between these extruders, characterized by a pressure regulating device which can regulate the pressure at the outlet of the first extruder (1).