A planetary extruder for producing and processing polymers includes a degassing section. The extruder includes a housing and a bushing arranged therein. The bushing has an internal toothing with a pitch diameter and a root circle. An externally toothed central spindle is arranged within the housing. Planetary spindles rotate about the central spindle between the central spindle and the bushing. A heat transfer fluid is guided through fluid channels which extend helically along an outer surface of the bushing and guide the heat transfer fluid axially. A degassing opening is provided to which a negative pressure is applied for degassing. A minimum radial thickness (t) of the bushing between the root circle of the internal toothing on an inside of the bushing and a bottom of the fluid channels on an outside of the bushing is selected based on the pitch diameter (d) of the internal toothing.

An mixing section for an extrusion screw has an inlet end and an outlet end as well as alternating wiping lands and barrier lands. The wiping lands have a greater helix angle than the barrier lands. The wiping lands and the barrier lands define inlet channels which narrow toward the outlet end and outlet channels which widen toward the outlet end. A helical pattern of mixing channels is cut into the wiping lands and the barrier lands. The mixing channels may be oriented generally at approximately right angles to the wiping lands and the barrier lands. A portion of the extrudate encounters the inside wall surfaces of the mixing channels and changes direction which improves the mixing of the extrudate.

An apparatus having an extrusion machine and a feeding unit. for producing foamed polymeric material, in particular polyethylene and polypropylene, is disclosed. The extrusion machine includes a cylindrical barrel which is connected with a first end thereof to the feeding unit to receive a blend of plastic material to be extruded, a parallel pair of screws in the cylindrical barrel, a driving unit for driving the screws into rotation in opposite directions, a gas tank containing CO.sub.2 as a foaming gas, injection means for injecting the foaming gas into the cylindrical barrel; a head mounted at a second end of the cylindrical barrel opposite to the first end and heating means arranged around the cylindrical barrel for transferring heat thereto.

The present invention relates to an extrusion die and a method for extruding a sheet using the same, and according to one aspect of the present invention, there is provided an extrusion die comprising a storage part configured to hold a raw material, the storage part defining a first width, a pressure part configured to move the raw material through the storage part, a first die defining a second width less than the first width, such that a flow width of the raw material becomes narrower, a second die in fluid communication with the first die, the second die defining a width that increases from the second width to a third width, such that the flow width of the raw material passing through the first die becomes wider and a flow thickness becomes smaller, and a heating part configured to heat the raw material passing through the second die.

In one embodiment, a method of forming an extruded board includes mixing a resin and a foaming agent, melting the mixed resin and foaming agent to form a uniformly colored extrudate, differentially expanding voids formed from the foaming agent within the uniformly colored extrudate by passing the uniformly colored extrudate through a breaker plate, forming a board with the differentially expanded voids and uniformly colored extrudate, and forming lightened portions on an outermost surface of the formed board.

Methods for forming small volumetric shapes of polymer derived ceramic materials, including reaction extrusion systems and processes. Systems and apparatus for forming small volumetric shapes of polymer derived ceramic materials, cured materials and pyrolized materials, including extruders. Polysilocarb polymer derived ceramic precursor formulations. A pneumatic handling device in associated with the extruder. The pneumatic handling device can cool, mix, mill and transport the cured material.

A device for making foam pipes and a method for making the foam pipes includes the use of critical micro foaming injection molding. The foaming agent and the foaming material are mixed and controlled under specific temperature to obtain micro bubbles in the wall of the foam pipes which need less material when compared with PVC pipes of same specification such that manufacturing cost is reduced.

A system for the production of carbonized biomass that includes an infeed for accepting biomass feed material and an associated twin screw extruder. A water heater is connected with respect to at least one inlet along a length of the twin screw extruder and a pressure sustaining valve is connected at an outlet of the twin screw extruder.

An extruder assembly has a frame with upstream and downstream ends. A barrel assembly on the frame has a passage. At least one material advancing component resides at least partially within the passage and is configured to be turned around an operating axis to thereby cause material to be conveyed from a passage inlet to a passage outlet. A drive assembly turns the at least one material advancing component around its operating axis and has a motor on the frame situated so that at least a part of the motor is in lengthwise overlapping relationship with the barrel assembly. The drive assembly is configured to turn the one material advancing component around its operating axis at a speed of at least 300 rpm.

A barrel main body, a sleeve, and a fixing mechanism (a fastening hole and a fastening device) are provided. The barrel main body includes a barrel hole having a cylindrical shape and a slit dividing an inner circumferential surface of the barrel hole. The sleeve having a hollow cylindrical shape is removably incorporated into the barrel hole. The slit includes two cutout surfaces facing each other with a space between. The fixing mechanism brings the inner circumferential surface of the barrel hole into close contact with the sleeve without any gap by narrowing the space between the cutout surfaces and deforming the barrel main body.