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 ).

Disclosed herein is a system comprising a first pump; a pelletization system that comprises an underwater pelletizer; where the pelletization system is located downstream of the first pump and is in fluid communication with it; a direct line that is located downstream of the first pump and upstream of the pelletization system; where the direct line does not contain a pump or a heat exchanger; and a bypass line that is located downstream of the first pump and upstream of the pelletization system; where the bypass line comprises a second pump; where the first pump is operative to discharge the polymer to the pelletization system via the direct line when the polymer has a melt viscosity greater than 10.sup.5 centipoise; and where the first pump is operative to discharge the polymer to the pelletization system via the bypass line when the polymer has a melt viscosity less than 10.sup.5 centipoise.

A method of forming a film (1) of molten polymer material, by extruding said material in a direction (2) out of a narrow exit slot (3), which is an integral part of a wider die chamber (4) of which the major dimension of extension is parallel with the major dimension of the exit slot (3), characterized in that the molten polymer material is formed into one or more flows generally parallel with said major dimension of the exit slot (3), each said flow being pumped in a re-circulating arrangement from the chamber inlet (7) to the outlet (8) through conduits connecting the inlet to the outlet, while fresh molten polymer material is administered from a reservoir into each re-circulating flow.

The present invention relates to water and solvent-free polymers, in particular water and solvent-free synthetic rubber products like non-halogenated and halogenated butyl rubber products as well as a process for the production thereof. The invention further relates to a device suitable to accomplish said process.

The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

The smoothing device for plastic films comprises plastic-melt-producing means (1, 5), an adjustable slit die (10) and a roller smoothing unit (16) having cooled smoothing rollers (11, 12), which form an adjustable smoothing gap (13) between each other. Optionally, further rollers (15) are arranged downstream. A thickness gauge (23) measures the thickness of the plastic-film web (22). A controller (30) for controlling the thickness of the plastic-film web (22) may set a setpoint thickness (SD) of the plastic-film web (22) and the volumetric flow rate (SS) of the plastic melt or the line speed (LS). The controller (30) captures the current torques and rotational speeds of the rollers (11, 12, 15) and the current thickness (FD, FD1-FDn) of the plastic-film web (22).

The controller (30) sends setpoint rotational speed signals (C0S, C2S-CnS, CAS) calculated from the captured torques of the rollers (11, 12, 15) to the drives of the rollers and a smoothing-gap setpoint distance signal (GW) for adjusting the smoothing gap (13), and furthermore—in the case of a specified line speed (LS)—setpoint plastic-melt volumetric flow rate signals (SS) to the plastic-melt-producing means, or—in the case of a specified plastic-melt volumetric flow rate (SS)—setpoint line speed signals (LS) to the drives of the rollers (12).

Embodiments of an invention disclosed herein relate to devices, processes, and systems for processing polymers.

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).

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 guiding means (40) is assembled for a rearrangement of the 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 the 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 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).