Abstract: An apparatus for filtering thermoplastic synthetic plastic material has a screw (5) bearingly supported within a housing (1) for rotation around its longitudinal axis for the transport and preferably also plasticizing of the synthethic plastic material. This material is supplied to the screw (5) through an intake opening (7) into the housing (1) and leaves the housing (1) through an exit opening (8). The screw (5) is subdivided into two sections (9, 10) disposed one behind the other in axial direction. A filter (40) provided with penetration openings (25) is disposed in the flow of the synthetic plastic material that is disposed between these two sections (9, 10), which filter (40) is disposed within the housing (1) between the two sections (9, 10) of the screw (5) so that it subdivides the interior of the housing. The filter (40) is connected for common rotation with at least one of the screw sections (9, 10).

Abstract: An extruder screw includes an energy transfer section divided into successive barrier sections in which a channel formed by a first thread is divided into at least two sub-channels by a second thread. A ratio of the difference in outer diameters of the threads is approximately inversely proportional to the ratio of the lengths of adjacent ones of the barrier sections.

Abstract: An improved twin screw extruder device (14) is provided which is capable of producing a wide variety of high quality extrudates having greatly varying final properties, without the need for extensive machine modifications. The extruder (14) includes a barrel (16) together with a co-rotating twin screw assembly (22). The assembly (22) is made up of a pair of screws (50, 52) having central, tapered shafts (54, 56) equipped with outwardly extending helical flighting (58, 60); the screws (50, 52) are non-parallel and are positioned so that the flighting (58, 60) thereof is intercalated along the length of the screws (50,52). The flighting is of specialized configuration and tapers along the length of the screws (50, 52) preferably at an angle of taper different than that of the shafts (54, 56); moreover, the width of the outer flighting surfaces (70, 72) increases along the length of the shafts (54, 56).

Abstract: An extruder screw for processing plastic material, in particular for a plasticizing barrel of an injection molding machine, has at least one screw flight divided along its length into successive zones including a mixing and transformation zone for plasticizing plastic material and a subsequent discharge zone for expelling plastic material. The screw flight is formed in the mixing and transformation zone with at least one breach to define a through passage for return of a partial mass flow to a neighboring screw turn, whereby the screw flight extends towards a discharge end of the discharge zone of the extruder screw along a helical line having same thread direction and being offset in axial direction in the area of the breach.

Abstract: A vented, multi-staged rotary screw extruder is taught for extruding thermoplastic materials. The screw has a final pumping-section of the screw that includes two or more channel depths which provides exit-pressure and flow stability. The channel-depth of the first segment of the final pumping-section is deeper than the channel depth of the second segment of the final pumping-section. The axial length of the first segment is preferably about two-thirds (⅔) of the final pumping-section length. The deeper first channel-depth acts as a reservoir resulting in smaller fluctuations in axial final fill-length as the input flow to the total pumping-section varies. The second channel-depth in the remaining approximate one-third (⅓) of the total pumping-section is preferably sized so as to optimize pressure development.

Abstract: The invention relates to an extruder in particular for processing polymer melts, with an extrusion space (4) which is arranged in an extruder barrel and through which at least one extruder screw shank (2) extends in such a way that it can be rotated by a motor, said screw shank having on it at least one section (5) which is in the form of a cylinder casing, the extrusion space (4) having at least one barrel section (1) which surrounds in an essentially equidistant manner the at least one extruder screw shank (2) in the area of the at least one region (5) in the form of a cylinder casing to form an encircling gap (17) as a restricted flow zone (blister 15), in particular to set the pressure of the melt.

Abstract: An extruder screw includes an energy transfer section divided into successive barrier sections in which a channel formed by a first thread is divided into at least two sub-channels by a second thread. A ratio of the difference in outer diameters of the threads is approximately inversely proportional to the ratio of the lengths of adjacent ones of the barrier sections.

Abstract: A vented, multi-staged rotary screw extruder is taught for extruding thermoplastic materials. The screw has a final pumping-section of the screw that includes two or more channel depths which provides exit-pressure and flow stability. The channel-depth of the first segment of the final pumping-section is deeper than the channel depth of the second segment of the final pumping-section. The axial length of the first segment is preferably about two-thirds (⅔) of the final pumping-section length. The deeper first channel-depth acts as a reservoir resulting in smaller fluctuations in axial final fill-length as the input flow to the total pumping-section varies. The second channel-depth in the remaining approximate one-third (⅓) of the total pumping-section is preferably sized so as to optimize pressure development.

Abstract: An extruder screw mechanism has a barrel that is heated by heating coils, an internal screw, and a cylindrical melt sleeve having a plurality of circumferentially spaced, axially extending, radial slots there through located between the external barrel and the internal screw. Another embodiment of the extruder has a barrel and an internal screw, with the internal screw having either a single central axial bore or a plurality of internal axial bores. The internal screw is provided with a plurality of external threads, with the threads each having a curved starting portion with a helix angle that has a finite value and gradually increases along an initial portion of the screw until the threads are substantially linear and parallel to the axis of the screw along the melting portion of the screw; a related embodiment has threadless portion separating the linear threads from the curved upstream threads.

Abstract: There is provided an injection apparatus comprised of a heating cylinder which is closed by a front end member having a nozzle. The apparatus is further comprised of a plasticating screw in the heating cylinder in a freely rotating and reciprocating manner, and a plunger connected to the front end of the screw. The plunger has a conical front end in which flow channels are formed. The front end member has a measuring chamber formed therein at an internal central location thereof. The measuring chamber has a predetermined length and an internal diameter which is reduced by 8 to 15% with respect to an internal diameter of the heating cylinder. The diameter of the injection plunger is set almost equal to the diameter of the measuring chamber, whereby the injection plunger is inserted into the measuring chamber in a freely reciprocating manner.

Abstract: A spiral conveyor for a concrete extrusion machine has a first spiral conveyor section with a first external diameter. There is a second spiral conveyor section having a second external diameter which is greater than the first diameter. The second section is spaced apart from the second section. A third spiral conveyor section is between the first section and the second section. The first end of the third section is connected to the first section and the second end is adjacent to the second section. The second spiral conveyor section may be mounted on a hollow shaft of the third section. The second section has two longitudinally divided components, each having a recess therein. Connectors interconnect the two components and a locking device is between the hollow shaft and the second section.

Abstract: A continuous mixing apparatus and process for preparing a rubber compound in an elongated mixing chamber defined by the volume between a radially inner surface of a stator and a radially outer surface of a rotor, the constituents being such that their mixing is capable of producing inside the mixing chamber a product in gaseous phase as the rubber compound is advanced through the elongated mixing chamber from an inlet to an outlet and in which, in at least a part of the mixing chamber, a stream of gas is circulated against the direction of advance of the rubber compound through the mixing chamber to carry the gaseous phase out of the mixing chamber.

Abstract: A barrel contains an extruder conveying screw which has a drive end, a feed section, a melting section and a pumping section wherein the screw has a vent hole located from 0 to 2 screw diameters from the beginning of the feed section. An axial bore in the screw vents gases from the barrel through the gas vent hole and into the axial bore.

Abstract: When a desired preform is to be molded from a molding material which is a polyester resin composed of a blend of PET and PEN by compressing and melting the molding material by the rotation of a screw in a heating cylinder and injecting and filling the molten material into a mold, a plastication zone 13 for the molding material is formed between a compression zone 12 of the injection screw 2 and a metering zone 14 at an end of the screw. In the plastication zone 13, the molding material is subjected to melting, relaxation, kneading and relaxation steps in order to melt and remove an unmolten material until the molten material reaches the metering zone 14. To prevent a molded article from becoming opaque and the production of a gel-like unmolten granular material when a polyester resin composed of a blend of PET and PEN is used as a molding material.

Abstract: A plasticating apparatus adapted to handle a wide variety of synthetic resinous materials without predrying. The plasticating apparatus includes a two-stage screw rotatably and reciprocably mounted within a barrel. A surge suppressor is provided between the first and second stages and is comprised of an integral protrusion of the screw root and a deep channel section immediately preceding the protrusion. The surge suppressor prevents the surge of molten material into the vent area following the holding portion of an injection molding cycle, thereby allowing faster recovery and preventing bleeding of plasticized material from the vent opening.

Abstract: A plasticating screw having improved mixing capability for polymer blends comprises a feed zone having a helical flight defining a solid material feed path, a compression zone for converting the solid material into molten material having a helical channel of variable depth, a waved melting zone for breaking up solid agglomerations and distributing them equally in the liquid melt, a spiral mixing zone that traps large agglomerations and contaminants, and a second melting zone for completing melting the material and for creating a substantially homogeneous melt. A method for mixing plastic material that has been at least partially plasticized and contains inhomogeneities is also described.

Abstract: An axially elongated extruder screw includes a screw body having an axially extending extruding portion defined by a feed section at an inlet end of the screw, a metering section at an outlet end of the screw and a barrier section between the feed and metering sections. At least one helical primary flight extends about and is coaxial with the screw body. The primary flight and the screw body cooperate to form a channel in the feed section for conveying resinous material to the barrier section. The barrier section includes at least one helical secondary flight extending from the primary flight about the screw body which in turn defines a first surface of revolution between the primary and secondary flights. At least one helical tertiary flight is positioned between the primary and secondary flights and also extends about the screw body which defines a second helical surface of revolution between the secondary and tertiary flights.

Abstract: An axially elongated extruder screw includes a screw body having an axially extending extruding portion defined by a feed section at an inlet end of the screw, a metering section at an outlet end of the screw and a barrier section between the feed and metering sections. At least one helical primary flight extends about and is coaxial with the screw body. The primary flight and the screw body cooperate to form a channel in the feed section for conveying resinous material to the barrier section. The barrier section includes at least one helical secondary flight extending from the primary flight about the screw body which in turn defines a first surface of revolution between the primary and secondary flights. At least one helical tertiary flight is positioned between the primary and secondary flights and also extends about the screw body which defines a second helical surface of revolution between the secondary and tertiary flights.

Abstract: An axially elongated extruder screw includes a screw body having an axially extending extruding portion defined by a feed section at an inlet end of the screw, a metering section at an outlet end of the screw and a barrier section between the feed and metering sections. A first helical primary flight extends continuously about and is coaxial with the screw body substantially along the entire length of the extruder screw. A second helical primary flight extends continuously at least part-way along the feed section to the outlet end of the extruder screw. The barrier section of the extruder screw defines first and second barrier flights positioned between the primary flights and cooperating therewith to form first and second melt and solids channels that extend along the barrier section of the extruder screw.

Abstract: A screw extruder (10) having a barrel (18) which has a bore (26) defining an inner surface (44) and one or more extruder screws (28), positioned within the bore (26). The extruder screw or screws (28) include a central shaft (34) and one or more screw flights (30). The extruder screw or screws (28) farther including one or more dispersive mixing elements (204), (234), (308), (406), (508), (558), which interact with the inner surface of the barrel (44) to form one or more progressively narrowing passages (46) through which material is forced into multiple regions of high elongational and shear stress (480, (120), (214), (310), (410), (510), (564).A second preferred embodiment is a screw extruder (10) having a barrel (18) having a bore (26) defining an inner surface (44) and one or more extruder screws (600), (701), positioned within the bore (26).

Abstract: A multichannel wave screw with a slush channel barrier section adapted to provide a consistent mixture of 50% solids and 50% melt to both channels of the double wave metering section. The screw includes a barrier flight having a relatively large initial clearance which allows solids to enter the newly formed slush channel. The barrier flight gradually decreases in clearance to a final barrier flight clearance which allows some dispersed solids to enter the slush channel. At the terminal end of the barrier section, the barrier flight abruptly increases its pitch, thereby abruptly narrowing the solids channel and therefore forcing solid material over the barrier flight and into the slush channel. In this manner, a uniform mixture of solid and melt is provided to the multi-channel wave metering section.

Abstract: Polyvinyl alcohol is processed into fiber or pellets for further processing, or directly into water-soluble film, in a screw-and-barrel extruder, which has a slow temperature rise and a mild kneading action achieved by a non-stick coating applied to the screw.

Abstract: A corotating multiple-screw extruder comprising first and second intermeshing screws of more than one flight. The first screw comprises first and second segments paired with first and second segments of the second screw, respectively. On the first segment of the first screw, the height of the first flight is less than the height of the second flight and on the second segment of the second screw, the height of the first flight is less than the height of the second flight and screws for use in such extruder.

Abstract: A multichannel wave plasticating screw having a feed section, barrier melting section, and metering section wherein solid material is transitioned from the trailing side of the primary flight to the push side of the primary flight at the terminal end of the barrier melting section. The solids transition is accomplished by interchanging, or "reversing" the diameter and width of the primary and secondary flights at the terminal end of the transition section. Alternatively, the barrier flight includes a short section of increased pitch at the terminal end of the barrier melt section which abruptly narrows the solids channel and thereby forces solid material over the barrier flight into the melt channel and on the pushing side of the primary flight. Transferring solid material from the trailing side to the push side of the primary flight increases the shear and pressure applied thereto and more quickly and efficiently melts solids.

Abstract: An injection screw comprise a rear end to a front end of an effective length of the screw compartmented in the order of a feed zone, a compression zone and a metering zone, wherein the metering zone is constituted by the first metering zone, the second metering zone and the relaxation zone. A root diameter of the second metering zone is formed in a smaller diameter than a root diameter of the first metering zone and a screw channel depth is set deeper than a screw channel depth of the first metering zone. Variations in a resin temperature at injecting is solved and melting and kneading through a entire screw further are improved by only partial changing of the configuration of the metering zone.

Abstract: Plasticating apparatus includes a barrel having an inlet for the introduction of resinous material and an outlet for the discharge of plasticated molten extrudate, along with a screw rotatably mounted within the barrel and in communication with the inlet and outlet for receiving resinous material, plasticating the resinous material, and discharging plasticated molten extrudate. The screw includes a helical flight with an outside diameter sized rotatably engaging an inside surface of the barrel and further, a helical valley disposed between flight lands of the helical flight within a transition section includes two root diameters, namely a rear root diameter and a forward root diameter, with the rear root diameter being larger than the forward root diameter proximate the inlet. In addition, a metering section is provided with special infeed and outfeed passages.

Abstract: An improved feed screw for injection molding machines has a metering section adjacent to the outlet having primary flights formed by a helical thread. The primary flights form primary channels therebetween for passage of the material. The primary channels are intersected by mixing flights formed by another helical thread having a hook shaped starting point extending from a main flight at the start of the metering section that continues in a general alignment with the primary flights. The mixing flights divide the primary channel into two secondary channels. The mixing flights include alternating oriented angular notches cut therethrough to provide passageway for the material between the two secondary channels to move in a general serpentine path.

Abstract: A screw extruder (10), including a barrel (18) having a bore (26) which defines an inner surface (24). At least one extruder screw (28) is positioned within the bore (26), each screw (28) further including a central shaft (34) and at least one screw flight (30). Each screw flight (30) further includes a front pushing face (36) and a rear face (38). The profile (40) of each front pushing face (36) acts with the inner surface (24) of the barrel (18) to form a progressively narrowing passage (46) through which material is forced into multiple regions of high elongational and shear stress (48) which act to break down agglomerates of material and thus dispersively mix the material.Also presented is a screw extruder (100) having a single screw (28) which includes dispersion disks (102) which are rotationally offset from one another and whose design is not constrained by interaction with a second disk, which provides improved distributive and dispersive mixing.

Abstract: An extruder for plasticating and extruding an extrudate, and an extrusion screw used with the extruder form the subject of this invention. The extruder screw includes an elongated root body and a thread portion helically wound about the root body and extending along the length. The screw having a low compression ratio, flight with a reduced helical angle, and a conical, tapered front end section where at least one-half flight of the thread has a pitch associated therewith which is different from the pitch of the remainder of the thread and where the diameter is less than the diameter of the remainder of the root body.

Abstract: An apparatus for shearing and straining polymeric process material, such a scrap tires includes a rotor and barrel. Large material pieces are feed into a hopper and the material is warmed, pressurized and transported to a rotor--barrel transfer section to initially chop the material to reduce its size. The material then passes to a rotor barrier or refining section where the material must pass over wide top barriers that extend across extrusion grooves. The barriers included multiple ridges and the barrier to bore clearance is progressively reduced as the material passes downstream. Ramp like grooves, where rejected material can be worked further, precede the barrier ridges. A rotor to barrel transfer section, having a conical barrel that can be longitudinally shifted, follows the wide top barriers, so the size to the discharged material can be regulated.

Abstract: An extruder for plasticating and extruding an extrudate, and an extrusion screw used with the extruder form the subject of this invention. The extruder screw includes an elongated root body and a thread portion helically wound about the root body and extending along the length. The screw having a low compression ratio, flight with a reduced helical angle, and a conical, tapered front end section where at least one-half flight of the thread has a pitch associated therewith which is different from the pitch of the remainder of the thread and where the diameter is less than the diameter of the remainder of the root body.

Abstract: An apparatus for solid state shear extrusion pulverization of a polymeric material comprising an elongated hollow barrel having a feed zone, a heating zone adjacent to the feed zone, a powder formation zone adjacent to the heating zone, and a powder discharge zone adjacent to the powder formation zone. At least one screw is housed within the elongated hollow barrel. A hopper is provided for feeding the polymeric material into the feed zone of the elongated hollow barrel. Barrel heaters and coolers are provided for heating the polymeric material to a temperature less than its decomposition temperature in the heating zone and for maintaining the polymeric material below its melting point in the powder formation zone. The screw comprises a high shear screw section for applying normal and shear forces within the powder formation zone to form a powder of the solid state polymeric material.

Abstract: A screw for a molding machine comprises a feed zone, a compression zone and a metering zone. The metering zone 12 is provided with a screw element having an intermediate mixing element 12b and a forward end mixing element 12a, and the upstream side of the intermediate mixing element is composed of a deep flight channel screw, and the downstream side of the intermediate mixing element is composed of a shallow flight channel screw.

Abstract: An extrusion screw (13) for an extruder (11) includes a screw shaft (24 ) which is rotatably arranged in a cylinder barrel (12). A main flight (25) and an auxiliary flight (26) are helically provided on the outer peripheral surface of the screw shaft (24). The trailing ends (25a, 26a) of these flights (25, 26) are spaced from each other by a half turn in the circumferential direction (A) of the screw shaft (24). A main flight groove (32) is formed between the front wall surface (27) of the main flight (25) and the rear wall surface (29) of the auxiliary flight (26). An auxiliary flight groove (31) is formed between the front wall surface (28) of the auxiliary flight (26) and the rear wall surface (30) of the main flight (25) to have a second cross-sectional area. The cross-sectional area of the auxiliary flight groove (31) decreases in a direction from the leading end (26b) to the trailing end (26a) of the auxiliary flight (26).

Abstract: Improved short length extrusion cooking devices (10) are provided which can achieve product throughput and quality characteristics of conventional long-barrel extruders. The short length extruders (10) of the invention include a relatively short barrel (14) having an inlet (18) and an endmost extrusion die (20). An elongated, helically flighted axially, rotatable screw assembly (22) is positioned within the barrel (14) and is coupled to motive means (39, 39a) for rotation of the assembly (22) at a speed of at least about 500 rpm. The device (10) includes an internal, apertured flow-restricting device (60, 110) which defines a mid-barrel choke point for the material being processed. Preferably, the barrel (14) has an internal bore of generally frustoconical configuration with an effective length to maximum diameter ratio (L/D) of at least about 6.

Abstract: An extruder screw having a plurality of plasticating sections sufficient for plasticating polymeric materials of different bulk density.

Abstract: An extruder apparatus for use in straining refining, separating and extruding thermo-plastic and rubber like process material includes a rotor positioned in barrel with a barrier section located between two barrel sections. The portion of the rotor in the barrier section has a smooth surface and the smooth surface and the barrier section are conical. The barrier section includes receiving and sending grooves separated by barriers. All material passing through the barrier section passes between the barriers and the smooth rotor section. Longitudinal movement of the smooth rotor section changes the clearance between the barriers and the rotor to restrict flow between a maximum flow and a closed position. The clearance can be adjusted so that different materials can be extruded in the same apparatus and adiabatic flow can be achieved. Discharge ports at the downstream end of the receiving grooves port rejected material to atmosphere.

Abstract: A screw for a double-screw extruder has its flight defining an outer cone and an inner cone of different convergencies with the inner cone converging more steeply than the outer cone from the feed end to the exit end of the extruder. Where A is the outer diameter at the feed end, B is the outer diameter at the exit end, C is the flight height at the feed end and D is the flight height at the exit end, the screw is defined by the relationship m.times.(A-B)/B=(C-D)/D where m is less than zero and greater than -0.75, the screw having a length L.gtoreq.15B.

Abstract: An extruder screw for use in the barrel of a plastic materials extruder is formed with a melt section which includes a melt flighting and a compaction channel and which also includes a barrier flight in which only smooth transitions are formed to prevent pressure surges or disruptions. The barrier flight rises radially outwardly of a forward wall of the melt channel, and defines a clearance space with the adjacent wall of the barrel which varies from a maximum at the beginning of the barrier flight to a minimum at the end of the barrier flight. The varying clearance between the barrier flight and the barrel wall approximates the change in viscosity of molten plastic material flowing over the barrier flight from the solids channel into the melt channel, so that a relatively constant shear energy input is applied to the molten plastic material flowing over the barrier flight.

Abstract: A method for injection molding polyethylene terephthalate by employing a vent type injection unit as means for omitting preliminary drying the resin, wherein the unit does not develop a poor screw biting, and even when the molding material is an undried uncrystallized or crystallized PET, can feed a certain amount of the material at all times to injection mold a desired transparent molded form such as a preform, and use the preform to produce a thin-wall container at a low cost.

Abstract: An apparatus for the physiochemical treatment and reaction of material which includes a pair of conveying screws which convey the material from an inlet to an outlet and wherein the portion of the material is recycled through spaced openings between the screws and wherein the material is introduced from one screw to the other screw in such a manner that an air space is created between the threads of the other screw so that air may be provided to or taken from the material being conveyed.

Abstract: A melt-sealing device for extruders for thermoplastic polymers or rubber for sealing off the gear unit side against high-melt pressure, in which sealing is effected by the configuration of the extruder screw which includes an intake section, a compression section having a channel depth that decreases in the conveying direction, a metering section with a constant screw channel depth, a smooth annular melt channel section, and a blister element with an annular gap for the sealing melt.

Abstract: A screw for a double-shaft extruding device having a shaft and a spiral flight provided at an outer periphery of the shaft. A height of the flight from an axis of the shaft is substantially constant. An angle of torsion of a spiral of the flight becomes smaller toward a shaft distal end. A cross-sectional area of extrusion formed by the shaft and the flight continuously increases from the shaft distal end to a shaft proximal end. Material can be smoothly discharged and completely extruded.

Abstract: An apparatus for extruding material is provided which includes a barrel and a screw. The barrel has an axis and an internal operating surface, the internal operating surface defining a barrel interior and a barrel helical thread portion which includes a plurality of grooves reducing in cross-sectional area from a maximum value to a minimum value in a direction axially opposite to the axial direction of flow of material through the barrel. The screw has an external operating surface and extending into the barrel interior, the external operating surface of the screw forming a screw helical thread portion having at least a first and second groove. Each of the first and second grooves has an upstream end, a downstream end, and a body portion extending between the upstream and downstream ends thereof, the first and second grooves being axially co-incident at at least a transition location and being at least partially axially co-extensive.

Abstract: An apparatus for filtering and extruding plastic scrap consists of an extruder housing having an interior chamber and an extruder worm received and supported for axial rotation in the chamber. The extruder worm includes a centrally located set of return threads which divide the chamber into first and second chamber portions. The housing further includes an intake opening in the first chamber portion for receiving raw material, an exit opening in the second chamber portion for discharging filtered material, and a degassing opening in the second chamber portion for discharging gasses from the chamber. A drive mechanism is provided for rotating the extruder worm. A filter channel connects the first and second chamber portions wherein the plastic material passes from the first chamber portion to the second chamber portion through the channel. The channel has an inlet opening in the first chamber portion and an outlet opening in the second chamber portion.

Abstract: A process and apparatus for pulverization of natural and synthetic polymeric material by heating to a pre-melt or softening temperature below its melting point, cooling and applying high normal and shear stresses sufficient to form fine powder, and fluidizing the powder in a gas stream preventing its agglomeration. The same process and apparatus is suitable for enhancement of reactivity of polymeric and solid monomeric material to form homopolymers, copolymers, and new polymeric materials.

Abstract: A process and apparatus for pulverization of natural and synthetic polymeric material by heating to a pre-melt or softening temperature below its melting point, cooling and applying normal and shear stresses sufficient to form fine powder, and fluidizing the powder in a gas stream preventing its agglomeration. The same process and apparatus is suitable for enhancement of reactivity of polymeric and solid monomeric material to form homopolymers, copolymers, and new polymeric materials.

Abstract: A process and apparatus for pulverization of thermosetting, crosslinked thermoplastic and natural polymeric materials by applying normal and shear stresses by oppositely rotating meshing conical screws sufficient to form fine powder. The process may be conducted at relatively low temperatures, and in the case of many materials, at ambient or near ambient temperature and pressure conditions. The fine powder may be fluidized to aid in its discharge.

Abstract: Convenient access for quick and thorough clean-out and maintenance of an openable mixing chamber and both rotors in two-rotor continuous mixers for plastic materials is advantageously achieved by making each rotor in three separate pieces: a drive journal, a rotor body (also called a "rotor section" or a "rotor") and a driven journal. These three separate pieces of each rotor are axially aligned, with the rotor body being positioned between the drive journal and the driven journal. Each rotor body is disengageably coupled to its respective drive and driven journals. The drive and driven journals are rotatably mounted in bearing assemblies which are separate from the mixing chamber barrel (also called a "mixing chamber housing").

Abstract: A plasticating apparatus having a barrel and a screw rotatably disposed therein. The screw has a mixing section including a helical conveying flight to form a helical passage for transporting resinous material along the screw. The mixing section further includes two helical divider flights, each spaced from the conveying flight to divide the helical passage into three channels of varying cyclic depth in the helical direction of the channels. The portions of minimum depth of the channels define wave crests which are helically displaced from each other.