Abstract: An injection molding process wherein the times of heating to melt a resin are reduced to minimize the thermal hysteresis and to decrease the deterioration of physical properties caused by the thermal hysteresis, so that high quality information recording disks may be produced. A molding process wherein the plasticating and the injection and filling of a material resin are carried out in separate cylinders, allows constant molding for a long period of time. A material resin such as polycarbonate is supplied without predrying to an injection apparatus for a first time molding. Resin is kneaded by the apparatus while volatile components are heated to be vaporized and exhausted through a vent port. An inert gas atmosphere is provided within the cylinder to prevent the material resin from being oxidized. Since predrying can be dispensed with, the thermal hysteresis will be extremely small and the deterioration of the resin caused by such heating may be suppressed.

Abstract: A process for preparing thermoplastics or polymer blends comprising (A) from 5 to 95% of a water-moist elastomer component containing up to 60% of residual water, (B) from 5 to 95% of a thermoplastic polymer, (C) from 0 to 95% of a further polymer, and (D) from 0 to 70% of additives, said process comprising mixing the components A to D in an extruder with mechanical dewatering of component A, wherein the extruder has at least two rotating screws and, in the conveying direction, is essentially composed of a metering section into which component A is fed, a squeeze section which serves for dewatering component A and contains a retarding element and an associated dewatering orifice which is present upstream of the retarding element by a distance corresponding to at least one screw diameter, a feed section in which the thermoplastic polymer B is introduced as a melt into the extruder, a plastication section with mixing or kneading elements, a devolatilization section with an orifice and in which the remaining wat

Abstract: The invention relates to a gear extruder for plasticizing and homogenizing rubber mixtures, having at least two gears disposed in chambers in the extruder housing, with the teeth of the gears meshing with one another, and having a port for feeding the rubber mixture to the front of the gears in the extruder housing. The invention is characterized in that gas vent ports are provided in the extruder housing, at the ends of the teeth of the gears, in an area in which the teeth disengage, and/or that at the entrance side of the teeth filled with the rubber mixture. The gas vent ports are provided in the extruder housing in one embodiment so that they extend on the entrance side over no more than half of the circumference of the chambers. By such an arrangement of gas vent ports it has become possible to ventilate a rubber mixture such that volatile components and moisture contained therein can be outgassed, but the rubber mixture is unable to enter the gas vent ports and clog them.

Abstract: In a process for extruding a thermoplastic resin in a single screw extruder, a barrel of a single screw extruder has a channel, a feed section and a first melt seal located after the feed section. The process is improved by supplying solid polymer into the feed section and venting moisture extracted from the polymer during the conversion of the polymer from a solid to a melt into a vent area and through a rear vent positioned in the feed section. An unfilled area within the channel of the barrel between the rear vent and the first melt seal forms the vent area.

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 cast polymer integral mixing and vacuum processor system and method for delivering substantially void-free viscous polymer employs a motor connected to a mixing screw. A tube surrounds the mixing screw with one end of the tube being fixedly connected relative to the motor. The mixing screw has a thread thereon having varying pitch zones. In a loading thread pitch zone a relatively wide thread pitch is provided for receiving dry material filler at a filler input and resin at a resin input. At a first mixing and sealing thread pitch zone, a relatively narrow thread pitch is provided so as to form a vacuum seal and provide mixing of the resin with the filler material. At a void removal thread pitch zone a substantially wide thread pitch is provided and at which a vacuum tower is located in which a vacuum is maintained to remove voids formed by gas in mixed material.

Abstract: A twin shaft continuous kneading extruder has a twin kneading feeder portion provided with two passages juxtaposed to each other within a casing. The passages are cocoon-shape in cross-section and hold two kneading shafts rotatably disposed in the respective passage portions. A single screw portion substantially extends one of the passages and holds a screw shaft that substantially extends one of the kneading feeder shafts. In addition, a plurality of mixing portions are provided on the twin kneading feeder portion. A first degassing open vent communicates with the kneading feeder shafts between mixing portions while a second vacuum degassing open vent is provided on the single screw portion. The first mixing portion keeps resin fed from a material feeding port in a semi-gelled condition. Thereafter, the resin is completely melted and kneaded in a second mixing portion after degassing. The resin is then fed to the single screw portion which subjects the resin to a vacuum degassing to be further extruded.

Abstract: The present invention is directed to a hopper structure for feeding a powdery material adapted to enable gas, etc., generated in a plasticizing cylinder to escape irrespective of the state of feed of the powdery material within a hopper.

Abstract: A screw extruder mechanism for the processing of strongly outgassing materials comprises a main extruder for proper material processing, a material feed and discharge device and a degassing device on the main extruder for the discharge of the gas stream from the portion of evaporation. For the gas stream to branch into at least three separate streams, the degassing device comprises a first degassing port and at least two degassing elements which are opposed radially to each other in relation to the main extruder and are disposed between the portion of evaporation and the first degassing port and which are designed preferably as ancillary screw extruders opening radially into the main extruder.

Abstract: The protein framework is developed in a continuously working 2-shaft kneading device for the production of paste product dough without--as was previously required--a dwelling time of 10-15 minutes in a mixing trough. In so doing, a so-called dry and crumbly dough is formed. This is transferred to a directly adjoining single-shaft screw press without the application of pressure if possible. The apparatus accordingly includes three characteristic process stages: a first whirling mixer for the intimate mixing of the dry components with water, a 2-shaft kneading device, and a single-shaft press.

Abstract: An apparatus and a method for molding of polyester articles having low acetaldehyde content directly from a melt without intermediate solidification of the molten polyester. A melt to mold process is used wherein an acetaldehyde stripping agent is mixed into a polyester melt before devolatilization in a flash tank. The devolatilized polyester is pumped out of the flash tank and injected into a mold, thus forming a shaped article. The apparatus may include one or more flash tanks in one devolatilization line, or multiple devolatilization lines may be used stemming from one main polymerization reactor. The final shaped article should contain less than 10 ppm of acetaldehyde.

Abstract: The present invention relates to an apparatus and method for producing molded polyester articles. More particularly, the invention concerns an apparatus and method for continuously producing molded polyester articles having low acetaldehyde content from a melt prepared by continuously reacting polyester precursors. The polyester is prepared and formed into useful shaped articles in a single, integrated, continuous melt-to-mold process without an intermediate solidification of the melt.

Abstract: Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 50% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in a mixing unit, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating screws and essentially includes, in the transport direction,one unheated metering section in which the elastomer component A is fed to the extruder by a metering means,at least one unheated squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice,at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder,at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements,at least one devolatilization section which is provided with at least one devolatilization orifice and in which

Abstract: The invention herein relates to a kind of slug production device for brick-making machines, specifically referring to a kind of slug production device that is mainly comprised of a raw brick mixture filler trough and a vacuum trough, below which are the the parallel and horizontal members of two pressure tubes and two forming tubes, and positioned at the rear of the two pressure tubes and the two forming tubes are a pair of pressure mechanisms and, furthermore, at the bottom section of the raw brick mixture filler trough and the vacuum trough is a swing-type aggregate crushing mechanism such that after the raw brick mixture is loaded into the filler trough, the raw brick mixture is conveyed precisely into the pressure tubes and the pressure mechanism pistons at the rear of the two pressure tubes operate in a reciprocal movement to convey the raw brick material slugs into the vacuum trough then the raw brick material aggregate conveyed into the vacuum trough are guided into the forming tubes by the pressure me

Abstract: A method and an apparatus for producing web-shaped plastic foil (19) is described, in which granulate or pulverulent polymer and particulate finer are intermingled, whereafter the mixture is extruded through a die aperture (18) for forming the finished plastic foil. In order to facilitate the intermingling of the above-disclosed starting materials, the granulate or pulverulent polymer is plasticized and de-aired prior to the admixture of the particulate filler.

Abstract: Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 60% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in an extruder, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating, in each case double-flight, screws and essentially includes, in the transport direction,a metering section in which the elastomer component A is fed to the extruder by a metering means,at least one squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice,at least one section provided with a conveying screw or at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements,at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder,at least one section provided with mixing, knead

Abstract: An extruder for the plastification and extrusion of a rubber mixture in the form of two cold material strips through two inlet passages (4, 5) has in a housing (1) two gears (2, 3) meshing with one another in the manner of a gear pump. The inlet passages (4, 5) are provided each in an insert (8, 9) which is held replaceably in the housing (1). In this manner it becomes possible, by exchanging the inserts (8, 9) to adapt to various materials to be worked by the extruder.

Abstract: Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 50% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in a mixing unit, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating, in each case triple-flight, screws and essentially includes, in the transport direction,one unheated metering section in which the elastomer component A is fed to the extruder by a metering means,at least one squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice,at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder,at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements,at least one devolatilization section which is provided with at least one devolatilization

Abstract: Essentially dry materials are obtained by mechanically dewatering water-moist rubber, prepared by emulsion polymerization and precipitation, to give a compact material having a rubber content of at least 50%, by a process in which the previously dewatered rubber is fed to the feed section of a twin-screw extruder which has screws rotating in the same direction and possesses, in succession in the conveying direction, at least two back-up zones and two associated dewatering orifices, each of which may be provided with a retaining screw, and at least one kneading zone, one devolatilization zone and finally one discharge zone, which may be closed by a die lip, and the water separated off is discharged at the dewatering orifices in liquid form.

Abstract: An extrusion method and apparatus for removing volatile contents from solid state resin materials is described. A cascade-type extruding device is used having first and second extruders. A top end portion of the first extruder 10 is directly connected to a rear side portion of a cylinder of the second extruder 100. Volatile contents of a melted resin, which is melted when the solid state resin material is supplied to the first extruder, are removed in a volatile content removing vacuum unit provided on an upstream side of the connection between the first and second extruders. The melted resin is then extruded from a nozzle provided at a top end portion of the second extruder. The volatile content removing vacuum region of the volatile content removing vacuum unit 140 extends over a first region, which is under the control of the first extruder, and a second region, which is under the control of the second extruder.

Abstract: Disclosed is a temperature control system and a kneading-mixing extruder apparatus implementing the temperature control system. The temperature control system includes a flow passage formed in a stationary disc having a plurality of holes provided in a kneading mechanism of the extruder apparatus, a fluid supply device for supplying temperature-adjusted fluid into the flow passage and a temperature control device for setting the temperature of the stationary disc to a desired target temperature.

Abstract: In a vent arrangement comprising a heating cylinder 1 containing therein a screw and provided with a vent hole 3 and a reduced pressure exhaust path 4 provided with a vacuum pump and connected to the vent hole 3 for draining volatile fractions of a material to be molded from the heating cylinder by reducing the pressure in the vent hole by means of the vacuum pump, said volatile fractions are removed by arranging in the exhaust path a filter unit 7 filled with a granular filtering material 8. The material to be molded is used for the filtering material 8. According to the above construction, it can be achieved to efficiently remove volatile matters by using the molded material as the filtering material of the filter unit arranged in the reduced pressure exhaust path of a vent arrangement.

Abstract: A multi-stage vacuum kneading-extruder includes a degassing chamber for storing material to be processed and reducing pressure of space for storing the material, a kneading-conveyer device for kneading while conveying the material sent from the degassing chamber, and an extruding mechanism for extruding the kneaded material, at a conveyer terminal end of the kneading-conveyer device, into a predetermined shape. The kneading-conveyer includes a pair of conveyer screws disposed one after another in a conveying direction of the material and a grinding-kneading mechanism interposed between the front and rear screws. The grinding-kneading mechanism includes a plurality of unit kneading mechanisms disposed in opposition to each other relative to the material conveying direction. Each of the unit kneading mechanisms includes an un-rotatable stationary disc, a rotary disc rotatable relative to the stationary disc and a stationary filter interposed between the stationary and rotary discs.

Abstract: Each of two screw bodies includes a feed screw and a kneading screw. The feed screw is formed of a wide-flight 1-lobe intermeshing screw designed so that the ratio W.sub.0 /D of the flight width W.sub.0 thereof to the screw diameter D ranges from 0.2 to 0.4. The kneading screw includes a plurality of double tipped kneading discs designed so that the ratio W/D of the width W thereof in the axial direction of the screw bodies to the screw diameter D ranges from 0.3 to 1.0, and displaced from one another in the circumferential direction of the kneading screw, the angle by which any two adjacent kneading discs being displaced range such that at least a backflow of an extrusion material can be prevented.

Abstract: A pug mill having a housing including a drive and bearings for rotatably mounting and driving a cantilevered shaft extending from one side of the housing. Associated with the housing and concentrically arranged about the shaft are, in seriatim, a vacuum chamber, a mixing chamber, an extruder and a reduction cone. A port about the shaft is positioned between the vacuum chamber and the mixing chamber. A source of vacuum maintains a vacuum within the vacuum chamber and creates a vacuum within the mixing chamber by air passing through the port. An auger associated with the shaft positioned within the extruder forces clay toward the reduction cone. This creates a seal for maintaining vacuum within the mixing chamber and extrudes cylindrical blocks of conditioned clay without significant air bubbles.

Abstract: The invention relates to a method for manufacturing a foaming synthetic material, for example, polystyrol, by means of an extruder, in whose entry the synthetic material is fed, to which by means of a fumigation aperture foaming gas in a liquid form, for example pentane, is introduced at a pressure maintaining the foaming gas in its liquid form, whereby throughout a following extruder region, the synthetic material provided with the foaming gas is homogenecised.

Abstract: An improved conveyer apparatus for processing and degassing a mixture of materials for forming solid surface end products, such as cultured marble and other polymer casting products. The conveyer includes a conveyer housing with an internal passageway having a conically shaped upstream section and a downstream section. A rotatable screw is located in the internal passageway and has a shape that corresponds to the shape of the internal passageway, so that an upstream section of the screw is conically shaped. The upstream section of the passageway has an inlet that connects to a source of materials, such as a mixer, and the downstream section has an outlet that permits the mixture of materials to exit the conveyer apparatus. A vacuum source is connected to the conveyer housing to remove gases from the mixture as it is being conveyed through the conveyer.

Abstract: Disclosed is a process for producing molded polyester articles having a low acetaldehyde content bya) reacting a glycol and a dicarboxylic acid in the melt phase to form a polyester having an I.V. of about 0.65-0.85,b) solidifying and pelletizing said polyester,c) remelting said polyester in an extruder, and,d) forming said polyester into shaped articles, wherein the polyester is devolatilized during or following said polymerization in the melt, while it is being remelted, after remelting, or any combination by passing a purge gas over said molten polyester.

Abstract: An apparatus for mixing and kneading raw materials, such as soap, and extruding the mixture into a predetermined shape. The apparatus includes a cylinder having a rotatable plodder worm shaft, a levigating mechanism disposed at a longitudinal position of the cylinder and including a rotary disc and a fixed disc fixed to the cylinder. The rotary disc and the fixed disc are disposed side by side along the axial direction of the plodder worm shaft and define a plurality of through holes allowing passage of the material in the axial direction. A flow passage forming member is disposed within a moving passage of the material between the rotary disc and the fixed disc and forms a flow passage allowing passage therethrough of fluid maintained at a predetermined temperature. A fluid supplying/exhausting device is provided for supplying the fluid at a predetermined flow rate to the flow passage and exhausting the fluid from the flow passage forming member.

Abstract: An apparatus suitable in particular for degassing fluoropolymers which have been subjected to thermal degradation contains--in the direction of flow of the product--a product intake, a coolable conveyor section, a comminution apparatus, a heated conveyor section and a product discharge, the entire apparatus being designed to be gastight and advantageously being designed to be resistant to pressure surges and having a gas outlet in the area of the coolable conveyor section and/or in the area of the comminution apparatuses.

Abstract: The present invention provides a barrel venting system for use on an extruder. Gases that are generated during plasticizing are drawn by vacuum through a filter to remove plastic particles before the gas is exhausted to the atmosphere. To enable cleaning of the filter without interrupting extruder operation, a shuttle valve is provided to allow rapid switching of the gas flow to a second filter. The valve itself includes two disc shaped elements with ports that align in two positions to enable flow to either the first or second filter, as desired.

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: The invention includes a shielding portion having a vent hole for discharging a gas composition G generated from a molten resin R to a barrel cylinder and having a shielding steam holding chamber C formed in connection with the barrel cylinder, the shielding steam holding chamber communicating with the vent hole. A steam supplying portion is provided for supplying a steam S to the shielding holding steam chamber C, and a discharging port portion is provided for discharging the steam S and the gas composition G from the inside of the shielding steam holding chamber C. Thereby, oxidization or carbonization of the molten resin can be prevented. In addition, adverse influence to the natural system can be removed and a decrease in the cost of the apparatus can be realized.

Abstract: A process for the extrusion of rigid PVC profile other than pipe is disclosed in a twin conical screw extruder, equipped with high shear screws. The process includes extruding a compound specially adapted for the process, the compound contains a polyvinyl chloride resin with an average particle size of from 130 to about 200 microns, a lubricant system containing no more than about 3.5 parts of one or more lubricants, an organo metal salt, from 0 to less than 0.75 parts of a polymeric processing aid, at least one filler/pigment, and a stabilizer for PVC. The process achieves extrudate surfaces characterized by a smooth, dull finish. The process advantageously operates at high extrusion output rates under the conditions specified.

Abstract: A method of injection molding polyethylene terephthalate without being predried or with having an irregular-shape wherein a vent type injection machine is employed and the vent is forcedly performed by vacuum suction within a range of a specified degree of vacuum, i.e. 50 to 150 torr (equal to 6666.1.about.19998.3 Pa.) and/or at the same time the material is forcedly fed by a feed screw having a specifically set revolution speed. According to the present invention, it is possible to provide an injection molding method in which an PET without being predried or with having an irregular-shape can be molded.

Abstract: A planetary gear for a multiple-screw extruder includes a circular stationary housing having internal teeth, a sun wheel formed from at least one toothed portion of a spindle, and a plurality of main planet wheels formed from at least one toothed free end of a plurality of screws and arranged in a circle. The plurality of main planet wheels are spaced from one another, from the sun wheel and from the internal housing teeth. A plurality of internal and external intermediate planet wheels are arranged between the sun wheel and the main planet wheels and between the main planet wheels and the internal housing teeth, respectively.

Abstract: A method and apparatus in the context of a pellet former (10) that is integral to an annular gap extruder/expander (11). A housing (30) is disposed around the annular gap extruder outlet end. Material is received from annular gap (37) on the face of a rotating disc (14) and, upon expansion, is directed into a roller area (43) by feed plows (23) or a screw flight (42). Pellet rollers (24) rotatably mounted on the disc push the material through a ring pellet die (22) disposed around the roller area. Cut off knives (25) attached to the disc cut the material into pellets as it exits the pellet die.

Abstract: A method and apparatus in the context of a rotating conveying screw situated within a cylindrical housing which has an inlet port on one end of the cylinder and a discharge opening on the other end of the cylinder. A resistance plate is mounted transversely to the conveying screw near the discharge opening for corotation with the screw. The plate is mounted to define a discharge gap between the opening and the plate. A sleeve on the housing is employed to adjust the size of the gap between the plate and the opening. A process controller positions the sleeve by means of a pair of screw jacks. The controller adjusts the discharge gap width to maintain feed material temperature within a predetermined band. Alternatively the controller adjusts the discharge gap width and feed screw speed to maintain a predetermined specific energy input into the feed material. The helical screw is preferably supported at both ends by a bearing means.

Abstract: A method which includes a flashing process and a process for extruding thermoplastic plastics is provided for achieving more thorough devolatilizing of the solutions of thermoplastic plastics, to ensure that the solutions of thermoplastic plastics are able to be worked continually, wherein the accoustic treatments are introduced into both processes to increase the efficiency of removing volatile components and thus leads to the decrease of the processing time for extruding thermoplastic plastics. In the flashing process, the ultrasonic horns are arranged to scatter the feed stream of the solution which increases the devolatilizing surface of the polymer fluid and, simultaneously, to enhance bubble formation and produce strong agitation in the polymer fluid, thereby increasing the devolatilizing efficiency. In the process of extruding thermoplastic plastics, the ultrasonic horns are arranged in the extruder to enhance both formation and rupture of bubbles, thereby increasing the devolatilizing efficiency.

Abstract: A method of reclaiming a plastic product having a paint film, including the steps of: obtaining crushed particles by crushing a plastic product having a paint film into particles of a predetermined size; supplying the crushed particles to a screw-type extruder; kneading and fusing the crushed particles while supplying water thereto; and obtaining a plastic by discharging a gas produced by decomposing the paint film and vaporized water.

Abstract: A method of extruding a substantially uniform polymer composition made up of polyvinylchloride, a stabilizing additive composition and at least one of two additional constituents, one of which is a mineral filler and the other of which is a normally liquid plasticizer for the polyvinylchloride; the method is achieved while avoiding use of compounded PVC as a starting material and includes the steps of: (I) providing an extruder; (II) operating the rotors of the extruder for essentially synchronous rotation in a common direction while maintaining in the extruder cavity a temperature sufficient to plasticize the polyvinylchloride; (III) feeding particulate polyvinylchloride and the additive composition without substantial premixing of the polyvinylchloride and the additive composition into the cavity at the first inlet (e.g.

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 method for compounding at least one polymerized alpha-olefin resin in an extruder including a screw having a feeding section, a melting section, and a venting section, which method includes: (1) introducing the resin and a heat transfer medium into the feeding section such that the resin is maintained at a temperature below its melting point; (2) transporting the resin and heat transfer medium to the melting section such that the resin is at a temperature which is at or just above its melting point by sublimation or vaporization of the heat transfer medium and kneading the resin at a temperature which is at or just above its melting point; (3) passing a resin melt of step (2) through a melt seal into a venting section wherein the heat transfer medium is released from the extruder; and (4) pumping the resin melt out of the extruder.

Abstract: A vent hole 3 for exhausting a gas component generated from a melted resin is provided at a heating cylinder. A gas staying chamber is formed at the interior by covering the upper portion of the vent hole, and there are provided a vent hole cover having a gas exhaust port at its upper portion and an inert gas supply unit for supplying an inert gas to the inside of the vent hole cover. Thereby the inert gas stays in the gas staying chamber, and a gas shielding layer for shielding the vent hole from the atmospheric air is formed.

Abstract: Process for producing from a rubber mixture blanks for finished parts in the rubber industry is composed of an extruder having a cylinder and a screw rotatable in the cylinder to plasticize a rubber mixture fed into the cylinder, an extrusion head and a gear pump between the extruder and the extrusion head for producing extrusion pressure and forcing the mixture through the extrusion head at a predetermined rate per unit time to form a uniform strand of predetermined shape which is cut into uniform lengths.

Abstract: A continuous process for extrusion of thermoplastic resin of sheets, films, etc., is characterized by introducing devolatilized polymer melt into at least two branch streams, at least one of which is fed to an extrusion device and at least one of the remaining stream is connected to a pressure-adjusting device so as to obtain high quality extrusion products.

Abstract: In the preparation and production of plastic materials by a continuously operating double shaft screw-type extruder, the efficiency of production often depends on good delivery of material to the extruder. In accordance with the invention for processing various types of plastic materials, a primary stage is mounted in a pressure-tight sealed manner on the housing of the extruder, the primary stage being formed by a vertical double conical container in which a pair of screw-type helices are rotatably supported and driven from above. The helices are connected to two replaceable feed elements at their lower ends so that delivery of material to the extruder is achieved without any intermediate dead spaces.

Abstract: A screw extruder having a barrel with a longitudinal bore for receiving a rotatable screw, a transverse bore disposed in the barrel tangential to the longitudinal bore for receiving and supporting a pin wherein the pin extends partially into the longitudinal bore. The tangential arrangement of the pin substantially decreases the susceptability of the pin to bending or breaking. The pin may also be adjustably positioned in the transverse bore and further may be subject to thermal heating and cooling.

Abstract: Disclosed is an apparatus for obtaining toner particles with improved dispersion of additive components therein comprised of a toner extrusion device containing therein a blending chamber, a screw mixing means, a heating means, a toner supply means, and a means for injecting the additive components into the extrusion device enabling a decrease in the melting temperature of the toner resin particles contained therein.

Abstract: A process and apparatus for the production of a polymer of thermoplastic polycondensate in which the polymer is first treated in a screw extruder and then in a mixing tank. In the extruder the polycondensate is heated in a first zone to a temperature below its melting point and thereafter it is heated to a temperature above its melting point at a vacuum. Water and other volatile components are removed from the first and second zones of the extruder. In the mixing tank the polymer is maintained under vacuum conditions and is conveyed and mixed by spiral mixing blades to remove residual water and volatile components. The polymer is discharged at the bottom of the mixing tank by a melt pump after a residence time of between 5 and 60 minutes in the mixing tank.