Abstract: A single-screw extruder for changing a morphology of a superabsorbent polymer, specifically a polymer gel. The single-screw extruder has an input aperture, a channel, a screw and an output aperture. The screw has a pitch value of a pitch of the screw flights along the conveying zone of the channel, where the channel has a mixing-element arrangement with at least one mixing element which protrudes into the channel of the single-screw extruder and which is configured for the mixing of the SAP polymer gel.

Abstract: A mixing device includes a first feed opening for a first liquid—preferably gas-laden—plastics component, a second feed opening for a second liquid plastics component, and a discharge opening for discharging a mixture of the first and the second liquid plastics component. The mixing device has a rotating agitator for mixing the first and second liquid plastics components, and a gap remains between the agitator and the discharge opening. An adjustment device is provided which either varies the gap by a relative movement between the discharge opening and the agitator, or varies the size of the discharge opening. A regulating device is connected in signal-transmitting fashion to a sensor for determining a pressure prevailing in the mixing device. The regulating device sets the gap, or the size of the discharge opening, by the adjustment device such that the pressure prevailing in the mixing device has a predetermined value.

Abstract: Embodiments of the presently-disclosed subject matter include extruder screws. Some embodiments of extruder screws include a screw body for placement in an extruder barrel, a plurality of ridges on the outer surface of the screw body that extend helically from an inlet end to an outlet end of the screw body, each adjacent pair of the ridges defining a channel, and one or more notches each extending across one of the plurality of ridges and between an adjacent pair of the channels. The notches can permit a material to flow from one channel into an adjacent channel, and the notches can define crosscuts that extend along the screw body and helically rotate in an opposite direction relative to the plurality of ridges. Furthermore, some extruder screws can further comprise one or more splitter rings.

Abstract: A 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.

Abstract: Embodiments of the presently-disclosed subject matter include extruder screws. Some embodiments of extruder screws include a screw body for placement in an extruder barrel, a plurality of ridges on the outer surface of the screw body that extend helically from an inlet end to an outlet end of the screw body, each adjacent pair of the ridges defining a channel, and one or more notches each extending across one of the plurality of ridges and between an adjacent pair of the channels. The notches can permit a material to flow from one channel into an adjacent channel, and the notches can define crosscuts that extend along the screw body and helically rotate in an opposite direction relative to the plurality of ridges. Furthermore, some extruder screws can further comprise one or more splitter rings.

Abstract: An apparatus for applying a liquid coating to a deicer composition, methods of applying a liquid coating to a deicer composition, and solid deicer compositions that have been coated using the apparatus or method of the invention are disclosed. The apparatus includes a screw conveyor that has a housing, at least one screw with a plurality of flights, an inlet for uncoated deicer, an inlet for a liquid coating composition, and an outlet for deicer coated with the liquid coating composition. The screws contain protrusions or tabs that extend from the surrounding surface of the screw. These protrusions or tabs aid in the mixing of the solid deicer and the liquid coating composition in order to provide a well-mixed deicer that resists caking while avoiding losing the coating composition to leaching.

Abstract: The present disclosure is directed to methods for preparing rubber compositions where those rubber compositions comprise at least one telechelic polymer and at least one filler. The methods make use of a mixer that includes a mixing chamber and at least one rotor with wings of specified configuration. Use of the disclosed methods yields a rubber composition with improved properties including an improved dispersion index after master batch mixing as compared to the same rubber composition mixed using standard 4 wing mixers.

Abstract: A single-screw extruder includes a grooved infeed system, a cylinder, and an extruder screw rotatably supported in the cylinder. The extruder screw has a softening zone, a main plasticizing zone, and a post-plasticizing zone and is at least double-threaded in the area of the main plasticizing zone. The cylinder at least partially has at least one groove extending substantially in the longitudinal direction in the region of the main plasticizing zone.

Abstract: A device is provided with which it is possible to produce poly(methyl methacrylate) bone-cement paste, which is degassed to the greatest extent possible, while avoiding large-volume mixing containers and large cement volumes contained therein. The device includes a tubular hollow body (10) having a first opening (30) on the input side and a second opening (20) on the output side, at least one rotatably-mounted shaft (40) arranged in the axial direction in the tubular hollow body (10), thread turns (50) arranged axially along the outer side of the shaft (40), wherein the shaft (40) has at least one section with thread turns (50) whose pitch decreases in the direction of the second opening (20), at least one stirring blade (60) arranged on the shaft (40), and rigid mixing elements (70) arranged on the inner side of the tubular hollow body (10).

Abstract: A method and a device for producing a thin article or a thin coating on a previously manufactured solid body. At least two reactive polymer materials are mixed together thoroughly and die resultant mixture is discharged via a nozzle in the form of a thin tube. This thin tube is pulverized or atomized by means of the introduction of a controlled flow of pressurized air with the result that die pulverized mixture may be sprayed onto an open mold or onto a surface or onto a previously manufactured solid body which is to be coated.

Abstract: A plasticizing screw for injection molding according to the present invention is installed in an injection molding machine that performs injection molding by plasticizing thermoplastic resin feedstock containing reinforcement fibers, and includes a shaft, a main flight, and a sub-flight. The protrusion height of the main flight from the circumferential surface of the shaft is formed to be constant in at least an area in which the sub-flight is provided.

Abstract: A plastication screw (1) comprises a shank (2) extending along a rectilinear axis (3), a feeding region (4) to supply a product to be plasticated, a plastication region (5) placed immediately downstream of the feeding region (4), relative to a main feeding direction (S) of the product along the axis (3) of the shank (2), at least one primary thread (7) extending in a helical development around the shank (2) at least in the plastication region (5), following a predetermined winding direction (V), and at least one secondary thread (10) extending in a helical development around the shank (2) in the same way as said predetermined winding direction (V), in at least part of the plastication region (5). The primary thread (7) and the secondary thread (10) each have a varying pitch (p1, p2). The pitch variation (p2) of the secondary thread (10) is greater than the pitch variation (p1) of the primary thread (7).

Abstract: Twin screw cooking extruders are provided requiring reduced specific mechanical energy inputs, through use of screw assemblies including first and second elongated, axially rotatable screws which are substantially coextensive in length, with the screw flighting presenting a pair of axially spaced apart sections of short pitch length and intermediate sections of greater pitch length. The intermediate sections have an axial length greater than about four times the length of the axially spaced apart sections.

Abstract: Conveyor apparatus and methods of conveying a foodstuff. A foodstuff conveyor apparatus may include a foodstuff inlet, a foodstuff outlet, and a conveyor chamber coupling the inlet to the outlet. A conveyor screw having an axis oriented longitudinally in the conveyor chamber may be configured to urge the foodstuff from the inlet towards the outlet. The conveyor screw may have a spindle at each end, with a spindle free portion between the spindles. The screw may be positioned in the conveyor chamber so that one spindle is near the outlet, and the other spindle is near the inlet. The spindles may be configured so that the pitch of the screw near the outlet is less than the pitch of the screw near the inlet to provide a mixing and compacting effect as the foodstuff is conveyed from the inlet to the outlet.

Abstract: An extruder comprises a displacement part with a housing, inside of which at least one screw shaft is housed and which is provided, at one end, with a material entry opening for the material to be processed and, at the other end, with a material outlet opening for the processed material, and with an intermediate opening between the material entry opening and the material outlet opening for discharging gas from the displacement part. A material retaining device is connected to said intermediate opening and has at least one screw shaft inside an intermediate housing. This screw shaft extends from the intermediate opening to a gas discharge opening in the intermediate housing and conveys material entering the intermediate housing back into the displacement part.

Abstract: An extrusion blowmolding apparatus has an extrusion die having an upstream portion for receiving the thermoplastic polyester material and a downstream portion having a die head through which molten thermoplastic polyester material is flowed to form a parison suitable for extrusion blowmolding. The extrusion die has extending therethrough a generally cylindrical barrel and an extrusion screw disposed within the barrel having spiral flights along its length. In some aspects, the flight depths are lengthened so to provide a good melt at a suitable throughput. By also selecting an appropriate extrusion temperature profile, it is possible to eliminate or minimize unmelts, which can contribute to processing difficulties as well as defects in the resulting article. In other aspects, a closed-loop drying system is provided for achieving very low moisture levels in the polyester material to improve processing.

Abstract: In the case of an extruder with at least two parallel, rotating shafts turning in the same direction, the shafts are equipped with interlocking feed screw segments (24) and working segments (26). The working segments (26), which lead to a greater spread between the two shafts than the feed screw segments (24), are formed as a single piece as a combined element (22) using the feed screw segment (24).

Abstract: Screw assemblies are provided for cooking extruders characterized by operation using significantly reduced specific mechanical energy inputs, wherein the screw assemblies include first and second elongated, axially rotatable screws which are substantially coextensive in length, with the screw flighting presenting a pair of axially spaced apart sections of short pitch length and an intermediate section of greater pitch length. The intermediate section has an axial length greater than about four times the length of the axially spaced apart sections. The screw assemblies permit incorporation of significantly greater amounts of steam into comestible products during cooking thereof, as compared with prior art designs.

Abstract: A plastication screw (1) comprises a shank (2) extending along a rectilinear axis (3), a feeding region (4) to supply a product to be plasticated, a plastication region (5) placed immediately downstream of the feeding region (4), relative to a main feeding direction (S) of the product along the axis (3) of the shank (2), at least one primary thread (7) extending in a helical development around the shank (2) at least in the plastication region (5), following a predetermined winding direction (V), and at least one secondary thread (10) extending in a helical development around the shank (2) in the same way as said predetermined winding direction (V), in at least part of the plastication region (5). The primary thread (7) and the secondary thread (10) each have a varying pitch (p1, p2). The pitch variation (p2) of the secondary thread (10) is greater than the pitch variation (p1) of the primary thread (7).

Abstract: The invention relates to an apparatus for extruding thermoplastic material, comprising an extruder screw (2) which is mounted in a housing (1), comprises a plasticizing section (P) on the inlet side, a degasification section (E) upstream of an outlet section (A), a flow arrester (S) between the plasticizing section (P) and the degasification section (E) with a screw section with a counter-rotating delivery flight (3), and at least one flow channel (5) bridging the flow arrester (S) and containing a melt filter (4). In order to reduce the driving power of the extruder screw (2) it is proposed that a sleeve (7), which encompasses the screw (6) and is mounted in the housing (1) in a rotationally fixed manner, is associated with the screw section that forms the flow arrester (S), and the screw (6) in the screw section of the flow arrester (S) has a smaller screw diameter in relation to the plasticizing section (P) and preferably also to the degasification section (E).

Abstract: Improved single screw extruders systems (40) are provided including a single screw extruder (42, 92) as well as an upstream preconditioner (44). The extruders (42, 92) include a single, internal, elongated, helically flighted, axially rotatable screw assembly (52) having one or more improved screw sections (74, 74a, 76). The screw sections (74, 74a, 76) include specially configured flighting (86) wherein adjacent flighting portions (86a, 86b) have smoothly arcuate surfaces (88) extending between the respective flighting portion peripheries (90a, 90b). This flighting design provides smooth, substantially surge-free operation while increasing SME and cook values. The preferred preconditioner (44) has independently controlled mixing shafts (106, 108) allowing the shafts (106, 108) to be rotated at different rotational speeds and/or directions.

Abstract: A novel barrier screw scientifically designed with new structural features that eliminate the shortcomings of the previous barrier screws and further improve their performance. The important new structural features include a structure of originating the barrier flight without creating any dead-spot while maintaining a constant solid channel width, a structure of terminating the barrier flight without creating any dead-spot while assuring good melt quality, a melt channel structure of avoiding excessively deep channel depth while assuring sufficient melt conveying capacity, and a solid channel structure of avoiding excessively large channel area with shallow channel depth while assuring good melt quality.

Abstract: To provide a kneading screw which can reduce such a phenomenon that a disproportional load is imposed onto a shaft of the kneading screw without degrading kneading performance of the kneading screw, a twin screw extruder with the kneading screw, and a method for assembling the kneading screw.

Abstract: A kneading screw is disclosed which comprises a screw body, the screw body comprising a feed section and a kneading section, the feed section comprising screw segments for feeding a to-be-kneaded material to a downstream side and the kneading section comprising kneading segments for kneading the material. The screw body is provided within the kneading section with a multi-stage portion which gradually changes axially in rotating outside diameter. It is preferable that the multi-stage portion be constituted by kneading segments of plural kneading discs different in rotating outside diameter. With such a construction, it is possible to avoid stress concentration on an axial part of the kneading screw and thereby prevent breaking of a spline shaft and abnormal wear of kneading flights.

Abstract: The clay extruder includes a drum 2 having a screw 4 having a rotary shaft 6, a spiral rotary blade 5 for feeding the clay under pressure while kneading the clay fed into the screw, a pressure raising portion 10 to feed the clay under pressure while kneading the clay, and a rectifying portion 11 provided on the side of an extrusion port 20 in the drum 2 to rectify the clay into a columnar shape. The rectifying portion 11 has a rectifying rotary blade 7 whose intervals being longer than that of the rotary blade; an angle formed between the face on the side of the extrusion port in a sectional shape of the rectifying rotary blade cut along the central line of the rotary shaft 6 and the central line gradually decreases, as the rectifying rotary blade comes close to the extrusion port.

Abstract: A clay kneader has a drum having a pressure raising section on a supply opening side, an extrusion section having an inner diameter smaller than that of the pressure raising section on side of an extrusion opening for extruding clay as a columnar article, and a flow controlling section located between the pressure raising section and the extrusion section and being equipped with a supply opening for clay, a screw having a rotary shaft having a diameter which gradually decreases toward the extrusion opening in the flow controlling section and being ended around a boundary between the flow controlling section and the extrusion section, and a helical rotating blade provided along the rotary shaft for kneading the clay a rotary shaft.

Abstract: An apparatus for wet granulating a powder material comprises: —a barrel having a granulation chamber and being provided with a first inlet (1) for receiving said powder material and for supplying it to said granulation chamber and with a second inlet (2) for receiving a granulating liquid and for supplying it to said granulation chamber, said granulation having an aperture (9) for discharge of granules from said barrel, and —a transporting means (S) for advancing said powder material toward the end of said granulation chamber while granulating it with the aid of said granulating liquid, said transporting means (S) comprising a first transport zone (4) at its rear end, an agglomeration zone (5) downstream from the first transport zone (4) and a second transport zone (8) at its front end, said first inlet (1) and said second inlet (2) being positioned above the first transport zone (4), wherein said aperture (9) has a shape tightly fitting the terminal portion of the transporting means (S) for directly discharg

Abstract: The object is to provide a method for manufacturing liquid crystalline resin composition having a hollow filler and a fibrous filler using a common melting-kneading extruder to maintain well-balanced relation between the residual percentages of hollow filler and the fiber length, which balance could not be attained in the prior art. A liquid crystalline resin composition having 5 to 30% by weight of hollow filler and 5 to 30% by weight of fibrous filler is manufactured using a melting-kneading extruder provided with a screw. (1) The liquid crystalline resin is fed from a main feed port located at upstream side in the extruding direction, while a hollow filler and a fibrous filler are fed from a side feed port located at downstream side in the extruding direction.

Abstract: The invention relates to a device for the extrusion of thermoplastic synthetic material featuring an extruder screw (2) which is mounted on a housing (1) including a plasticizing section (P) at the inlet side, a degassing section which is mounted upstream on a discharge section (A) and a conveying outlet (3) operating in the opposite direction which is located between the plasticizing section (P) and the degassing section (E). A flow channel (5) that contains a melt filter (4) is bridged over by at least one of the conveying outlets (3) in the opposite direction. To create favorable production conditions, the extruder screw (2) forms a similar conveying outlet (7) operating in the same direction between the conveying outlet (3) in the opposite direction and the downstream port (6) of the flow channel (5). The housing (1) has at least one degassing vent (8) at the transition area of the conveying outlet (3) operating in the opposite direction and the conveying outlet (7) operating in the same direction.

Abstract: A mixing and kneading machine (1) for continual compounding comprises a screw shaft (3) rotating in a casing (2) and simultaneously moving axially translationally. To sustainably enhance the efficiency of the machine as regards its material thruput per unit of time the screw shaft (3) comprises at least four groups of radial screw vanes (4a, 4b, 4c, 4d) evenly distributed circumferentially, each group consisting of a plurality of screw vanes in axial sequence. The outer diameter (Da) of the screw shaft ranges from 400 to 800 millimeters. The rotary speed of the screw shaft (3) ranges from 30 to 80 rpm. A mixing and kneading machine (1) engineered as such is particularly suitable for compounding an anodic mass in the production of electrodes—anodes—for the aluminum industry.

Abstract: Improved, high Specific Mechanical Energy extrusion systems (20) are provided including a single or twin extruder (22) and an upstream preconditioner (24). The extruder (22) includes an elongated barrel (26) with at least one elongated, axially flighted, rotatable screw assembly (58) therein. The barrel (26) includes a mid-barrel variable restriction valve assembly (32), and the screw assembly (58) has a disrupting/homogenizing screw section (66) therein upstream of the valve assembly (32). The screw section (66) includes a plurality of alternating pitch screw parts (82-92). Preferably, the barrel (26) also has an atmospheric vent (36) downstream of the valve assembly (32).

Abstract: A rotor segment is assembled in a screw set for use in a twin-screw extruder for mixing and dispersing a material to be kneaded into a kneaded product having a desired state of kneading. The rotor segment has a plurality of kneading blades that provide a plurality of tip clearances different from each other at least in the circumferential direction. The rotor segment also has the same sectional shape as a screw and a kneading disk, which are assembled in other screw segment and kneading disk segment of the screw set, except for crest portions of the kneading blades. A degradation in quality of a kneaded product attributable to residence of a target material of kneading for a long time can be satisfactorily prevented. A load partially imposed on the rotor segment can be reduced, thereby preventing a damage of the screw set in which the rotor segment is assembled.

Abstract: A method of injection molding or extruding a polymer composition having a predetermined bulk density associated with particles, granules or pellets of the polymer composition and a predetermined melt density when the polymer composition is fully melted and compressed. The method of the invention employs a screw having a volume compression ratio that is greater than or equal to the ratio of the predetermined melt density to the predetermined bulk density of the polymer composition and up to 1.25 × the ratio of the predetermined melt density to the predetermined bulk density of the polymer composition.

Abstract: An extruder includes a barrel and a kneading screw extending through the barrel in a rotatable fashion. The kneading screw is provided with a devolatilization portion. The devolatilization portion includes a kneading flight that is twisted in a direction for transferring a material downstream. The kneading flight kneads the material while transferring the material downstream and separates a volatile component from the material. Impregnation sections, which allow the kneading chamber to be impregnated with the material, are respectively disposed adjacent to an upstream side and a downstream side of the devolatilization portion so that the air-tightness of the devolatilization portion of the extruder is maintained. Accordingly, an efficient devolatilization operation of the material is achieved.

Abstract: An extruder screw mixing section has a plurality of threads formed on a body of the screw with a pitch defining mixing channels for moving material in a direction from a feed end to a discharge end of the screw. The threads and the mixing channels are interrupted by counter channels that divide the mixing channels into segments of similar diminishing depth profile. A portion of the material moves through the counter channels in direction from the discharge end to the feed end to promote better mixing and melting of the material.

Abstract: Method and device for reprocessing a thermoplastic polycondensate, in particular for the recycling of thermoplastic polycondensates, such as polyethylene terephthalate, polyester or polyamide is provided. The polycondensate is introduced into an extruder in a solid state. The polycondensate is then heated to a temperature below melting temperature and degassed or dried at below atmospheric pressure or with an inert gas added. Preferably, to prevent the polycondensate flakes from escaping through a degassing opening, a conveying device is used to convey the escaping flakes back into the extruder. The dried flakes are then melted.

Abstract: In the field of continuous mixer apparatus for commingling particulate thermoplastic materials, employing at least one main rotor with a helical profile body configuration, an improved profile for the peripheral threads is provided. It presents a first upstream feed flight having a plurality of Lowenherz profile outer threads and second downstream feed flight having a plurality of screw-type outer threads, both being adjacent and integral with the periphery of the main rotor.

Abstract: An optically clear thermoplastic resin composition is disclosed which comprises structural units derived from substituted or unsubstituted polycarbonate and substituted or unsubstituted polyester, wherein said polyester comprises structural units derived from terephthalic acid and a mixture of 1,4-cyclohexane dimethanol and ethylene glycol, wherein said ethylene glycol is greater than about 60 mole percent based on total moles of 1,4-cyclohexane dimethanol and ethylene glycol. In addition the composition disclosed possess good environmental stress cracking resistance, flow and thermal properties.

Abstract: A plasticating screw for an extruder or an extrusion press has a thread change, whereby the volume of the transporting cross-section does not change and thus a pressure increase in the region of the thread is avoided. To this end, in the region wherein a first and a second screw thread of the plasticating screw overlap, the thread width outside the overlapping region is equal to d and the thread width inside the overlapping region is equal to ½ d.

Abstract: A kneading apparatus includes a barrel having a chamber, which is a tubular hollow, a biaxial screw set for extruding a material to be kneaded downstream by rotation of the biaxial screw set inside the chamber, and kneading blade sections, mounted in the screw set, for kneading the material by shearing the material in tip clearances and a wedge-shaped space between an inside wall of the chamber and the kneading blade sections. The tip clearance becomes narrower from the upstream side to the downstream side in the direction of extrusion of the material. The kneading apparatus, which performs a continuous kneading operation, makes it possible to set proper kneading conditions in accordance with changes in the state of a material being continuously kneaded, and achieves high kneading efficiency.

Abstract: High levels of treated fumed silica, processing fluid and high molecular weight silicone polymer are continuously compounded into a homogeneous silica filled heat-vulcanizable silicone composition by forming a premix in a continuous annular layer mixer and continuously discharging the premix into a compounding apparatus for compounding to form the filled heat-vulcanizable silicone composition.

Abstract: Apparatus according to this invention for plasticating a resin polymer, especially polypropylene, includes a barrel having an inlet, outlet, and inner surface. A screw, located within and closely spaced from the inner surface of the barrel, has a longitudinal axis extending from the inlet toward the outlet, and includes length sections arranged in a series along the axis. The screw includes a core and a main flight located on and projecting radially from the core, extending in a helix along the axis, and having a push side and a trailing side. The screw sections include a feed section, a transition section following the feed section, a metering section following the transition section, and a barrier melting section following the metering section.

Abstract: A process for injection-foaming a thermoplastic resin by using an injection molding machine with a two-stage-compression screw, injecting a physical foaming agent into the cylinder of the machine at a pressure lower than the storage pressure of the physical foaming agent, mixing it with a melted resin and expanding the volume of the cavity of the mold at the time of injection, and an injection molding machine and resin composition suitable therefore.

Abstract: An extrusion molding apparatus comprises a shaping die for producing a ceramic molded product, and a screw extruder having built therein an extruding screw (40) for mixing while leading a ceramic material forward. The extruding screw (40) includes a pressing screw portion (410) having a first lead (411) and a dispersing screw portion (420) having a second lead (421) adjacent to a forward end (412) of the pressing screw portion (410). The second lead (421) is formed in such a manner that the rear ends of all the second lead surfaces (426) at the rear end (422) of the dispersing screw portion (420) and the forward end of the first lead surface (416) at the forward end (412) of the pressing screw portion (410) are displaced from each other.

Abstract: The extruding apparatus has the molding die to form the ceramic molding, the screw extruder containing the extrusion screw to knead and guide the ceramic material toward the molding die. The extrusion screw is comprised of the pressure screw part and the diffusion screw part. The diffusion screw part provided at the front end of the extrusion screw has a diameter greater than the screw diameter of the pressure screw part.

Abstract: An extruder capable of obtaining a treatment volume equal to that of the conventional art without enlarging a screw diameter is provided. The extruder includes screw shafts, a drive unit, and a barrel, in which three or more screw shafts having the same diameter and the same root diameter in a waveform shape are engaged with each other and arranged in parallel to each other horizontally or nearly horizontally, while a distance between axial centers is made equal. According to the above configuration, the same treatment volume as that of a conventional extruder can be handled by screw shafts of smaller diameter as compared with that of the conventional art. By using the screw shafts of the smaller diameter as compared with the conventional art, temperature irregularities of an extrusion material in screw grooves, leakage of the extrusion material from the screw shafts, an installation area of the extruder, and the like conventional trouble of various kinds can be eliminated.

Abstract: The invention relates to a single screw extruder comprising a barrier screw and a barrel in which the barrier screw is held in a manner that permits to rotate and comprising at least one feed zone longitudinal section and at least one melting zone longitudinal section (23). The extruder (10) is characterized in that the barrel (11), on the inner wall (50) thereof in the area of the melting zone longitudinal section (23), has at least one groove (52) which runs in a longitudinal direction. The invention also relates to a method for extruding plastic material using a single screw extruder (10) comprising a barrier screw (40) which is held inside a cylinder (11) in a manner that permits it to rotate, whereby the extruder (10) comprises a feed zone (21, 22) and a melting zone (23), and the barrier screw (40) has at least one solid matter channel (49) and a melting channel (48).

Abstract: An apparatus for homogenizing and/or dispersing at least one viscous substance and at least one solid and/or at least one other substance of different viscosity includes in a space in a housing axis-parallel rotatable shafts disposed along a circle with equal central-angle distance and provided with tightly intermeshing screw elements. The shafts in the area outside the openings in the housing are provided with screw elements having a pitch (S) of at most three quarters of the outside screw diameter (D) over a length (L=L1+L2+L3) corresponding to at least ten times the outside diameter (D) of the screw elements.

Abstract: A rotatable screw for moving material in a plasticating process along an axis through a conduit from an inlet to an outlet. The screw having a feed section, barrier melting section, reorientation section and metering section disposed sequentially downstream. The screw includes an axial core, and a helical main flight that extends radially from the core and is formed with recesses located at the first periphery and extending through the thickness of the main flight and radially toward the core. A helical secondary flight extends radially from the core between successive helical passes of the main flight, and is formed with recesses extending through the secondary flight and toward the core. Materials conveyed along the metering section can cross through the main flight at the recesses and recirculate, in addition to passing over the periphery of the secondary flight, for still further enhanced and homogenous mixing, before reaching the outlet.

Abstract: A kneading apparatus includes a barrel having a cylindrical chamber; a screw assembly rotating in the chamber so that a material to be kneaded is extruded in the axial direction by the rotation, the screw assembly including a screw section having helical blades and a kneading blade section in order to allow the material to flow into the clearance between the inner wall of the chamber and the kneading blade section, and to apply shearing forces to the material; a metering feeder for feeding the material at a substantially constant volumetric or gravimetric rate into the chamber; an injecting device for injecting a heat-removing medium into the chamber; and a discharging device for separating the heat-removing medium from the material and discharging the heat-removing medium from the chamber. A kneading method using the kneading apparatus is also disclosed.