Abstract: The barrel (20) comprises at least two intersecting lobes (21a,21b) of cylindrical bores having parallel axes each corresponding to a screw and defining in the region of their intersection at least two longitudinal parallel edges (22). Each lobe comprises at least one shearing zone (23a,23b) adapted to cooperate with a shearing element mounted on the respective screws. The shearing zone (23a,23b) of each lobe is formed by least one groove (24a,24b) extending in the direction of the flow of the material and provided on the inner side of the barrel (20), the groove providing therebetween and each edge (22) a portion of a continuous surface of the cylindrical bore forming the corresponding lobe.

Abstract: An improvement in a method and apparatus is provided in extruding a powder material to form an article, in which the material is passed through an extruder and then through a die, wherein the material is provided in the form of a mixture which includes a vehicle, the improvement comprising having one or more gear pumps in succession between the extruder and the die, so that the powder material passes through the gear pump(s) after it leaves the extruder and before it enters the die. The gear pump(s) can have one or more pair of gears which are arranged sequentially with respect to the flow of the material.

Abstract: A segmented barrel extruder device for extrusion and having a plurality of segments enclosing an extruder barrel aligned on an axis. The segments include axially perpendicular rectangular end flanges having exposed sides and a central portion for housing an extruder barrel. The flanges have aligned straight line paths for fluid flow in a plane perpendicular to the axis. Accordingly, the paths each intersect two exposed sides without intersecting the central portion. The segments also include an extruder barrel between flanges. The segments have a housing having straight axial channels which are connected to the paths in the flanges to conduct fluid from points along one path in each path to of points along a corresponding path. The barrel extruder also includes a centered portion aligned with the flange central portion. There is also provided an extruder barrel insert sized to fit in the centered portion of the barrel having a key for preventing rotational movement.

Abstract: A process for continuously producing a heat-vulcanizable silicone rubber compound, which includes the steps of:(i) mixing (A) a diorganopolysiloxane having a viscosity as measured at 25.degree. C. of 1.times.10.sup.5 cP or more, (B) an inorganic filler and (C) a processing aid, as basic ingredients, by a high-speed mechanical shearing machine, thereby to obtain a flowable particulate mixture in which each ingredient is present in a substantially uniformly and finely dispersed state, and(ii) continuously feeding, at a constant feed rate, said particulate mixture to a continuously kneading and extruding machine through a feed opening thereof, which machine has two screws rotating in the same direction, thereby to obtain a homogeneous silicone rubber compound from a discharge opening of said kneading and extruding machine.

Abstract: This invention discloses an improved method for powder PVC extrusion using particulate PVC resin specified herein which enables smooth, dull surfaces for extrudates under broad processing conditions, in particular at relatively lower shear and temperature. The resins are characterized as having an average particle size ranging from 50 to 125 microns, a DOP porosity of from about 0.27 cc/gm to about 0.5 cc/gm, and a friability rating of 5 or less, preferably 2 or less depending on the stock temperature range during extrusion.

Abstract: Remoldable panels of a high melting point, high tenacity thermoplastic polymer and a thermosensitive organic filler are produced by forming a mixture of polymer and filler, extruding the mixture to form a web and calendaring the web prior to its solidification. The mixture is formed and extruded in a single step by separately feeding the polymer and the thermosensitive filler into an integral mixing and extruding space that has a feed end and an extrusion end and includes a pair of co-rotating parallel elongated elements. Each of the co-rotating parallel elements has a length extending between the feed end and the extrusion end of the integral space. At least three helical extrusion sections are distanced along the length of the elements and at least two kneading sections are included.

Abstract: An elastomer masterbatch or a compounded productive elastomer stock is made using a twin screw extruder to mix elastomer components in multiple mixing zones at controlled temperatures. Elastomer and other ingredients are fed into the twin screw extruder continuously through precise loss-in-weight or volumetric feeders. The degradation temperature and/or cross linking temperature of the elastomer determines the rate at which the elastomer can be processed, since friction created during mixing heats the elastomer. Accordingly, the maximum rate of compounding is a function of the torque limit, cooling efficiency, and conveying capacity of the extruder. The conveying capacity and torque limit are also a function of the size of the extruder. The viscosity of the elastomer compound in the extruder, as measured by a Mooney viscosimeter (ASTM D1646), is typically in the range of about 20 to 250 units (ML(1+4)100C).

Abstract: A pulverizing/kneading apparatus for pulverizing and kneading a material such as a soap compound. The material is supplied in a barrel in which are provided a pair of shafts respectively having feeding helical gears and returning helical gears. The material supplied is kneaded and the fine particles contained in the material pulverized by the gears. The forward driving force of the feeding gears is larger than the backward driving force of the returning gears so that the material advances forwardly toward the discharge opening of the barrel.

Abstract: An extrusion device for processing thermoplastic plastics material and rubber has a housing and primary screw means rotatably mounted therein. The device includes a discharge zone in which a sleeve member provided with external flights is mounted on a bearing shaft so as to be rotatable about its longitudinal axis, which sleeve member is drivable by the primary screw means but in an opposite direction thereto so as to increase the discharge pressure acting on the material being processed.

Abstract: An apparatus for extracting a liquid from a workable mass of material includes a first screw section for transporting the material, a second screw section which applies a force on the material in a direction generally opposite that of the transport direction, and a second screw extruder at or near a liquid extraction location which provides a pinch point on the material. The pinch point substantially eliminates liquid flow countercurrent to the material transport direction.

Abstract: A pasta is prepared by mixing particulate cereal semolina, which has a particle size of less than 300 .mu.m, with water in amounts so that the semolina-water mixture has a water content of from 30% to 35% by weight, and then the moistened semolina is kneaded and then extruded. The mixing, kneading and extrusion is carried out in an extrusion unit which has two identical parallel screws which rotate in the same direction. The temperature of the product which is mixed, kneaded and extruded is maintained below 55.degree. C.

Abstract: A method of degassing a molten mass of thermoplastic, plastics material containing residual monomers and a twin-screw extruder capable of effecting such degassing. A molten mass of plastics material and a stripping agent are intermixed at a pressure which prevents the stripping agent from changing from liquid to gas at the temperature of the molten mass. The pressure necessary is achieved by the use of a pressure restrictor, which is yoke-shaped and is connected to the extruder housing in a force-fitting manner using centering means but which effectively blocks the processing chamber of the extruder downstream thereof to the molten material with the exception of a maximum of two throughbores for such material.

Abstract: An apparatus for making center-filled chewing gum, in which product having up to at least 35-40% by weight of center fill can be produced. The apparatus includes a novel extruder barrel and nozzle arrangement (11) which extrudes a tubular rope of gum (G) through an annular orifice (30), and at the same time supplies a center-fill material (F) to the hollow interior (V) of the tubular rope through a central nozzle (20,21) concentric with the orifice. The center-fill material is fed into the hollow interior of the gum rope at a rate sufficient to just fill the void produced in the gum rope as it is extruded through the nozzle, and without exerting a compressive pressure thereon. With this apparatus, center-filled chewing gum can be produced with up to at least 35-40% by weight of center-fill material and at the same time uniform wall thickness and consistency for the center-filled product can be maintained.

Abstract: A supercritical fluid such as CO.sub.2 is injected under pressure into a fully cooked dough in an extruder. The dough is prepared and after being preconditioning with water and steam, is supplied to an extruder/cooker where it is subjected to high cooking temperatures, which may be on the order of 120.degree. C. The cooked dough is conveyed through an optional steam vent section and is cooled to a temperature of usually less than 100.degree. C. to prevent puffing of the extruded product by the conversion of water to steam. Supercritical CO.sub.2 is injected into the cooked and cooled dough, and under the pressure conditions existing in the extruder, the CO.sub.2 dissolves into the water phase of the dough. Since the conditions within the extruder are either subcritical or near-critical, various flavors, colorants, or other materials soluble in and carried by the supercritical CO.sub.2 are deposited and mixed into the dough before exiting the extruder. The dissolved CO.sub.

Abstract: A corrosion-resistant and wear resistant housing for a screw extruder having one or more axis-parallel bores, each of which accommodates a screw of the extruder. Support sleeves, which have a smaller internal diameter than the screw bore or bores and which guide the rotating screw or screws are disposed in the two end regions of the housing poritons, whereby the corrosion and wear caused by the material being extruded are primarily restricted to the support sleeves.

Abstract: A blender for plastic materials weighs a charge of virgin plastic pellets as they are added to a hopper, similarly weighs plastics regrind material as it is added to the hopper, calculates the weight of color material (or other additive) on the basis of the actual virgin material weight and the desired color percentage, calculates from the weight of color material and a calibration of a volumetric feeder the volumetric amount of color material needed and then dispenses the calculated volume of color material. The apparatus is hybrid, using weight ratio measuring devices for the primary components and a volumetric feeder for dispensing the additives.

Abstract: A method for producing a rubber mixture. In a first stage, in a ram kneader, a master batch is produced, and in a second stage, in a batch-type process, a final mixture is produced in a ram-less kneader, without the need for intermediate storage. To improve the cooling in the ram-less kneader, the interior of this kneader is supplied with air that has such a degree of dryness that a condensation deposit is precluded. To achieve this, an essentially air tight channel is provided between the two kneaders, with a place being provided in the channel for the bottom closure of the ram kneader in a swung-out position of this closure.

Abstract: A multi-shaft thin-layer reactor for treating fluid materials in which gaseous material is present during such treatment. The treatment involves the addition of gas to the fluid material or the removal of gas therefrom. The reactor includes a housing in which a plurality of axis-parallel conveying shafts are disposed. The housing is cylindrical and the shafts are disposed around the inner periphery thereof in such a manner that each shaft meshes with the two shafts adjacent thereto. The meshing shafts jointly define the outer periphery of a treatment chamber within the housing. At least one sun-and-planet roller extrusion assembly rotates the shafts and is adjacent at least one end of the shafts in a form-locking manner. The conveying shafts also scrape against the internal wall of the housing so that thin layers of the fluid materials fed into the reactor are formed and these thin layers become disposed on the conveyor shafts.

Abstract: An apparatus for treating molten material wherein a gas is present during such treatment either by being removed from the molten material or by being added thereto. The apparatus comprises a housing having a continuous spindle or a pair of spindles disposed therein. The continuous spindle is externally threaded at least in its end regions, and the pair of spindles is externally threaded. A plurality of planet spindles are dispoed circumferentially around the spindle are spindles. The planet spindles are also threaded and intermesh with one another as well as with the spindle or spindles. Furthermore, the internal wall of the housing is threaded and intermeshes with the threaded planet spindles. A treatment chamber is defined within the housing and the planet spindles define a wall surface of such chamber. The intermeshing components produce thin layers of the molten material which is carried, by the planet spindles, into the treatment chamber.

Abstract: Fiber-reinforced polymer compositions containing resin components including (a) 30-90 weight % of polyamide resins, and (b) 10-70 weight % of polyolefins+unsaturated carboxylic acid-modified polyolefins, based on the resin components; and (c) 5-50 parts by weight of glass fibers per 100 parts by weight of the total compositions, a molar ratio of end amino groups in the polyamide resins to carboxyl groups in the modified polyolefins being 10-1000. The compositions have a morphology in which polyolefin domains having an average size of 0.5-5 .mu.m are uniformly dispersed in polyamide matrix phases.

Abstract: The invention relates to a process for the processing of a thermoplastic polycondensation polymer by supplying the polymer in finely distributed form to a first vented extruder in which the polymer is devolatilized at a temperature below its melting temperature. The polymer is then placed in a second extruder where the polymer is transported below the melting temperature of the polymer over a first length of the screw from the inlet of the extruder, with constant evacuation of volatile components by means of a vacuum exhausting device at a vacuum of less than 10 mbar and the polymer is compressed and melted over a second length of the screw and then leaves the extruder as an end product of a semimanufacture.

Abstract: An agglomerating process and an apparatus therefor for preparation of sinter mix having the basis of kneading with vibration to make raw feed in capillary state and then agglomerating the kneaded material with tumbling vibration. By using the particular process, apparatus and various kinds of raw feeds, sintering characteristics of the product shows superiority in size distribution, permeability, strength, and activities, resulting cost, power and material consumptions of the process are remarkably improved.

Abstract: A compound steel workpiece and a process for its production, wherein a support jacket is provided with at least one recess, which in turn is furnished with a lining resistant to attrition and corrosion, which lining is connected to the support jacket by a metal bond. In the process, which has particular application in the production of double or multiple screw cylinders for use in plastics processing, the support jacket is provided with at least one core at the point(s) at which the recess(es) are desired, is subjected to hot-forming, along with the core(s), at an appropriate temperature, in particular for cross-sectional reduction a cross-sectional shape deviating from that of a circle is imparted to the core(s) and the recess(es) are created in the core(s).

Abstract: The removal of impurities, for example monomeric low-molecular substances, solvents or the like, from polymeric synthetic plastics materials takes place by the admixture of extraction gas in a first extruder in a supercritical state. The mixture is transferred to a second extruder where, in a first separating zone, and by a counter-current method, it is cleansed of the major part of the extraction gas containing the impurities, this being passed through a discharge orifice. Separation of any residue takes place in a vacuum zone on the downstream side. The high pressure in the first extruder is maintained by a counter-pressure valve in the connecting pipe between the first and second extruders. By the separation of contaminated extraction gas from molten synthetic plastics material in a closed space, namely the second extruder, it is possible to achieve an ordered dissipation of extraction gas on the one hand and molten synthetic plastics material on the other hand.

Abstract: A method and an apparatus for extruding a ceramic batch supplied from a vacuum auger machine into a formed body by a plunger molding machine, wherein the temperature distribution of the ceramic batch at the outlet portion is measured and is controlled so as to supply the ceramic batch having substantially a uniform temperature to the plunger molding machine from the vacuum auger machine.

Abstract: An extruding apparatus having a reservoir for reserving a treatment-object material including a main raw material, additives or auxiliary materials, a screw disposed within a material-conveying passage and for conveying the material to a terminal end, and an extruding die disposed at the terminal end and for extruding the material into a predetermined shape. The material-conveying passage includes a pair of discs disposed at intermediate positions in the conveying direction of the screw and opposed to each other transverse relative to the passage. Each of the discs defines a plurality of slit pores extending in the material conveying direction, with one disc being operatively coupled with the screw to be rotatable relative to the other disc. The disc pair constitutues a milling-kneading mechanism for milling and kneading the material by causing the material to pass through the slit pores formed by the disc pair.

Abstract: A segmented extruder device for extrusion along a longitudinal axis. The device has a plurality of segments enclosing a barrel aligned on the axis. The segments each include a pair of axially perpendicular end flanges for each segment. Each of the flanges have exposed sides and a central portion for housing an extruder barrel. The flanges have a plurality of straight line paths for fluid flow into and out of the flanges in a plane perpendicular to the axis. A port is provided to give access to each straight line path from at least one side of each flange. A housing portion is placed between each of the pair of flanges for housing the extruder barrel. The housing has a plurality of straight axial channels operably connecting the flanges to conduct fluid along the barrel from each of the straight line paths in one flange to a corresponding straight line path in the other flange. Finally, the device includes an inlet and an outlet for introducing fluid into and removing fluid from selective paths and channels.

Abstract: A method for extruding polyvinyl alcohol which includesadding sufficient energy to the polyvinyl alcohol to both melt it and essentially eliminate the crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol andrapidly cooling the extruded melt reduces the heat history and improves the resulting color of the extrudable polyvinyl alcohol.

Abstract: A single or twin-screw device is used to incorporate additives in a thermoplastic plastics material melt. The or each barrel of the extruder includes a first feed aperture for the introduction of the melt and a second feed aperture downstream thereof for the introduction of the additives. A screw is mounted on a shaft in each barrel and includes a core and a helical flight. In the region of the second feed aperture, the flight is replaced by alternating disc members and spacer members mounted on the shaft. The diameter or major dimension of the disc members is approximately equal to the combined diameter of the screw core and its flight while the diameter of the spacer members is approximately equal to that of the screw core. The disc members have profiled downstream faces. The disc and spacing members increase mixing and consequently throughput in the region of the second feed aperture.

Abstract: The present invention provides a novel method for producing a filler-containing colored thermoplastic resin composition superior in pigment dispersibility and impact resistance. This method includes melt kneading firstly at least a part of components of resin consisting of a thermoplastic resin (A) and/or a thermoplastic resin composition (B) with fillers (C), adding remainder of the resin, if any, with a pigment (E), and then further carrying out continuous melt-kneading.

Abstract: 50 to 95 parts by weight starch and 5 to 50 parts by weight polyvinyl alcohol with a degree of saponification between 87 and 100% are thoroughly mixed and furthermore the moisture content of the mixture is regulated between 10 and 25 weight %. Subsequently the mixture obtained is subjected to a thermo-mechanical treatment at a temperature situated between 110.degree. and 180.degree. C. During the extrusion the mixture is subjected to shearing forces so that the product obtained when it is dispersed in cold water and subsequently is centrifuged, divides into a watery phase and a coacervate phase without a sediment of undissolved polyvinyl alcohol being formed.

Abstract: A molded solid body of incinerated waste material and a method of making the same, which is formed by binding ash-like incinerated waste material with solidifiable molten plastic waste material and extruding a mixture of the same into a bar-like shape. The molded solid body is dense and rigid having a high rate of specific gravity so that it can consistently remain at a particular location regardless of environmental pollution when disposed in the sea and also, be used as a structural material for concrete and asphalt construction. According to the making method, two kinds of waste materials are processed at one time and reduced in volume to a rate ranging from 1/10 to 1/20, whereby the efficiency for transportation and disposal can be improved greatly.

Abstract: A briquetter for low density materials having a hopper, an auger in the bottom portion of the hopper extending outwardly of the hopper with its leading end feeding material conveyed by the auger and a pair of rolls receiving the feed material having briquette forming pockets extending along the roll circumferences, arranged to form complementary pockets for shaping the briquettes transversely of the rolls. A pair of confronting, threaded auxiliary ribbon flights in the hopper are provided immediately above the auger for pre-compressing material as it enters the auger. The auxiliary ribbon flights are tapered in diameter and have threads that become progressively smaller and are in opposite directions so as to concentrate pressure on material entering the auger. The leading end of the auger is smaller in diameter than the threads of the auger and is pointed to concentrate pressure on materials introduced between the pair of rolls.

Abstract: A twin screw extruder with a material homogenizing unit is the subject of this disclosure. Two extruder screws are located within a housing positioned and configured so that screw turns and screw lands of a first screw mesh with respective screw lands and screw turns of a second screw. A homogenizing zone housing is connected to the dual cylinder housing. Two cell rotors are connected to respective extruder screws and are located within the homogenizing zone housing. A plurality of radially distributed cell walls may be disposed on each cell rotor defining a plurality of open conveyor cells where the cell rotors and cell walls of each rotor are configured to mesh a cell wall with an opposing conveyor cell. The cell walls may be arranged with a slope differing from a slope of the extruder screws. The cell walls may be arranged parallel to or at an angle to an axis of said cell rotors.

Abstract: Electrode materials containing active material in a fibrillated polymer binder are formed continuously into a cohesive electrode component by utilizing a barrel for processing the electrode materials. A mechanism is provided in the barrel for axially advancing the electrode materials, while mixing and kneading the materials to fibrillate the polymer binder. A forming means at the end of the barrel receives the resultant mixture and continuously forms a cohesive component of fibrillated polymer binder and active material as other electrode materials continue to be advanced and processed in the barrel.

Abstract: An unsaturated-polyester-resin-based mass to be moulded, obtained from a pulsating screw mixer, is compressed into brick-shaped compacted articles of suitable dimensions and then subjected to a radio frequency to bring it to a high temperature and render it suitable for immediate compression moulding.

Abstract: Auxiliary or stub augers are used in conjunction with a convention auger machine that is used to form reinforced hollow cored slabs. They can be used to ensure consolidation of concrete above the cores particularly and relatively in large diameter slabs or can be substituted for one or more of the conventional core forming augers if a core or bore is not required in the slab at that location. The stub auger consists of a first portion having a non tapering shaft and a non tapering flight thereon. The second or downstream portion has a gradually reducing diameter shaft with the flight which continues from the flight around the first portion, decreasing in diameter to substantially zero at the extreme downstream end of the shaft.

Abstract: An apparatus and method for continuously dispensing dough for making bread, rolls, buns and the like by pressurizing and homogenizing the dough by a pair of open-flighted augers in a tunnel having minimal clearances so that the dough is provided with a uniform texture and density which permits a division into pieces having weights with tolerances within one-half of one percent.

Abstract: In a method for preparing caseinates, including the introduction of casein, alkaline solutions or basic salts and water into an extruder, the constituents being thoroughly mixed together and then subjected to an increase in pressure and temperature under the influence of return elements, it is provided, to achieve a finished basic product while avoiding a separate comminuting stage following the extrusion process, that the pressure built-up under the influence of return elements or kneading units takes place directly in front of the discharge end of the extruder and the product be discharged freely through this end of the extruder. An apparatus is used to carry out the method, this apparatus being characterised in that the return elemnts or return kneading units are arranged directly in front of the discharge end of the extruder and the discharge end of the extruder is open essentially without any reduction in cross-section relative to the free cross-section of the extruder.

Abstract: Removing chloroprene dimers from polychloroprene by feeding to a screw extruder a polychloroprene latex and coagulating the latex in the extruder, feeding the coagulated latex to a dewatering zone and discharging the coagulated polychloroprene through a flow restriction which heats and pressurizes the polychloroprene to an area of reduced pressure to form a porous crumb. Also, the flow restriction applies back pressure sufficient that the water in the polychloroprene is forced out of a vent port. The polychloroprene crumb discharged from the extruder is heated to strip chloroprene dimer therefrom.

Abstract: An extruder for degassing a thermoplastic plastics material melt comprises at least one screw mounted for rotation in a barrel. The barrel includes a first feed aperture for the introduction of the melt and a degassing port downstream thereof connectable to means for degassing the melt. The at least one screw is mounted on a shaft and has a helical flight. In the region of the port, the flight is replaced by alternating disc members and spacer members mounted on the shaft. The diameter or major dimension of the disc members corresponds substantially to the combined diameter of the screw core and its flight whilst the diameter of the spacer members corresponds to that of the screw core. The disc members have profiled downstream faces and the thickness of each disc member and each spacer member lies in the range of 0.1 to 0.5 times the diameter of the screw.

Abstract: A preheater and feeder for thermoplastifiable material supplied to an extruder for synthetic resin has the counterrotating worms in a heated housing delivering the material at a rate determined by the worm speeds. The worms are hollow and the major portion of the heat, apart from friction heat, contributed to the material is delivered by passing a heating fluid through the hollow worms.

Abstract: Apparatus for mixing material in a twin screw extruder by longitudinally advancing material by the interengaging threads of two screws in the housing of a twin screw extruder such that a plurality of separate streams of material are advanced by the threads of the screws, combining the separate streams of material in a thread-free zone of the screws in which the passage area for the streams of material undergoes uniform reduction and lateral displacement around one of the screws, and thereafter dividing the combined stream back into separate streams downstream of the thread-free zone. In the thread-free zone, a baffle element is mounted on the shaft of one of the screws, the baffle element being of conical shape and increasing uniformly in diameter in the direction of advance of the product.

Abstract: A process and an apparatus for continuously producing a rubber mixture. In the process, the constituents of the mixture are fed into a twin-screw extruder and are masticated and homogenized therein, with approximately 5% of the mixture being discharged and the remainder being recycled for further homogenization and for mixing with fresh batches of the constituents being fed into the extruder. The recycled mixture is circulated to and returned from a cooled, annular chamber dispersed exteriorly of the chamber of the twin-screw extruder, with the annular chamber having outflow and inflow passages communicating with the interior of the extruder.

Abstract: A support for photographic paper is produced by a method including the steps of coating one or two surfaces of a substrate sheet with a resinous melt includes a water-proof thermoplastic polymer and a pigment, by a melt-extrude-coating method, and solidifying the coating layer of the resinous melt on the substrate sheet, and wherein at least one melt-kneading procedure is applied to the resinous melt in a melt extruder having a pair of biaxial screws engaged with each other and satisfying the relationship (i)L.gtoreq.20D (I)wherein L is a length of the screws and D is a diameter of the screws, and provided with at least one pair of kneading disks located in at least a portion of the screws.

Abstract: The apparatus for processing synthetic thermoplastic material includes a receiving container, containing a disintegrating and blending member, which is disposed near the bottom of the container and which rotates about the axis of the container and with which a screw extruder is in flow connection through an opening in the wall of the container. For a trouble-free, absolutely even and continuous charging of the screw extruder, irrespective of temperature and rotational speed, the arrangement is such that the cylinder, surrounding the extruder screw of the screw extruder, opens out with its front-end charging opening at least approximately tangentially in the inside wall of the receiving container.

Abstract: A method and apparatus are provided for producing a mixture of plastics materials which are capable of being foamed with propellants. The method permits plastics materials, which require considerably different processing conditions, to be fused, homogenized and mixed with a propellant in an extruder. By feeding a high-molecular weight high-temperature resistant plastics material into the extruder through a first feed opening and subsequently feeding a low-molecular weight, low-temperature-resistant plastics material into the extruder through a second feed opening disposed downstream of the first feed opening but where the first plastics material is in a fused and homogeneous state and by introducing the propellant through a third feed opening downstream of the second feed opening, the desired homogenisation of the two plastics materials and propellant is ensured.

Abstract: A continuous granulator of the double-screw type includes a mechanism by which the degree of kneading can be controlled, and prevents lateral communication between the screw ends. A gear pump connected after the screw cylinders delivers the material to the cutting unit.

Abstract: A planetary gear extruder for the compounding and extrusion of thermoplastic materials, in which an annular groove is formed in the metallic stop ring to receive a ceramic body which is engageable by the forward ends of the planetary spindles in order to reduce friction. A ceramic body may additionally also be arranged in a recess in the end face of each of the planetary spindles, aligned with and adapted to engage the ceramic body mounted in the stop ring. As a result, the coefficients of friction between the stop ring and the end faces of the spindles are reduced considerably, consequently reducing the wear on the planetary spindles themselves and the central spindle.

Abstract: A process is provided which produces a waterproof membrane and applies this waterproof membrane directly to a fixed substrate. The process includes the steps of providing a polymeric material; melting the polymeric material; forcing the melted polymeric material through a movable die, the movable die shaping the polymeric material melt into a film; moving the movable die across the fixed substrate; and applying the film directly to the fixed substrate forming a waterproof membrane. The polymeric material is one of those known in the art to be useful as roofing material. In a preferred embodiment, this process produces a sealing membrane which is applied to a roof of a structure forming a membrane effective to protect the structure from intrusion of water. In another aspect, an apparatus is provided which is capable of performing the process of this invention.