Abstract: Apparatus for continuously manufacturing chip-and fiber-board webs having uniform thickness across their width in a press comprising a centrally disposed press cylinder journalled to rotate in bearings in uprights and at least one pressure roller disposed adjacent to periphery of the press cylinder. An endless steel band which carries the material for forming the web and which is subjected to tensile stress, is guided around the press cylinder and through the nip defined between the press cylinder and the pressure roller. The material is then pressed between the endless steel band and the surface of the press cylinder. The pressure roller is journalled for rotation in bearing bodies at each of its ends, with the bearing bodies being connected to piston and cylinder arrangements. When the press is in its loaded state, the bearing body at one end of the pressure roller is displaced by the application of a preselected pressure towards the axis of rotation of the press cylinder.

Abstract: A process and an apparatus for optimal operation of a high-speed extruder in which a pin-lined barrel section and a Transfermix section, both known per se but separately used, are utilized together in an extruder. The combination of these mixing systems allows in a surprising way an increase in the material throughput of 60% to 100%, with the mixing quality remaining the same and the drive torque being halved. The static extrudate pressure can be further increased by arranging an adjustable restriction device downstream of the extruder screw, thereby permitting a further increase in the output rate.

Abstract: An arrangement for cutting thin-walled reinforced closed bands of rubber into rectangular belts having the same width is suggested wherein the closed band is tensioned between two rollers. By deflecting one of the two rollers, the closed band experiences a force component parallel to the roller fixed in position which drives the closed band against a stop. With this arrangement of the stop on the end facing toward the cutting device even thin-walled closed bands can be cut into rectangular belts with a uniformity in width not attained previously.

Abstract: A press for the continuous production of thin chipboard and fibreboard includes a central rotatable drum and a feed roller; a nip being defined between the curved exterior surfaces of the drum and roller. An endless steel band passes around a major portion of the curved surfaces of both drum and roller and passes through the nip. Other rollers are provided for guiding, tensioning and applying pressure to the band. The feed roller has a large diameter, of at least 2 m, and is provided with drive means so as to be rotatable. These features, surprisingly, enable the board output to be increasing while, at the same time improving the physical characteristics of the board.

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: A pin transfer extruder is provided, wherein the pin-barrel and transfer mixing sections, which are known per se and have only been used individually hitherto, are jointly used in one extruder. Throttle pins, which are disposed in the transfer mixing section in the region of the greatest housing thread volume, permit universal use of the extruder in respect of the extruded material. The combination of both mixing systems permits the throughput of material to be increased in a surprising manner by 60% to 100%, while a constant mixing quality is maintained and the driving torque is halved. The number of the housing and screw flights remains independent of the cross-sectional area of the housing and screw threads because the number of housing and screw threads is constant.

Abstract: A single-screw degassing extruder for thermoplastic plastics materials and rubber is provided, wherein the pin-barrel and transfer sections, which are known per se and have only been used individually hitherto, are jointly used in one extruder. Throttle pins, which are disposed in the transfer section in the region of the greatest housing thread volume, permit universal use of the extruder in respect of the extruded material or combinations of extruded material and stripping agent, since the mixing efficiency of the extruder and the pressure of the extruded material upstream of a degassing opening in the extruder are thereby advantageously controllable.

Abstract: A method for reverse degassing a melt of thermoplastic plastics material and an extrusion device therefor. Thermoplastic plastics materials are fed into the extrusion device either in the form a melt or as a granulated, which latter is fused to form a melt. A portion of the melt is separated from the main melt stream. The extrusion device includes, in a downstream direction, a return-blocking zone, a degassing zone, a feed zone and a conveying zone. The separated portion is removed from the feed zone, the conveying zone or even a feed conduit leading into the feed zone if the material is already molten. The extrusion device also includes screw means rotating in a barrel. The screw has at least two different flight portions, one in the returning-blocking zone and the other in at least the degassing zone.

Abstract: A high-performance extruder is provided, wherein the pin-barrel and transfer mix mixing sections, which are known per se and have only been used individually hitherto, are jointly used in one extruder. The combination of both mixing systems permits the throughput of material to be increased in a surprising manner by 60% to 100%, while a constant mixing quality is maintained and the driving torque is halved.

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: 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 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: A calender assembly having at least two calender rollers mounted on axles and which jointly define a calendering nip with at least one of the rollers being mounted for rotation in a support column. Each roller includes a roller axle and a roller core and at least one of the rollers is provided with a removable shell. The axle of the roller provided with the shell is provided with a bearing member acted upon by a plurality of bearing body portions. Adjustment devices are provided for displacing the bearing body portions towards and away from the bearing member. Such movement of the body portions away from the bearing member defines an aperture through which the shell on the roller can be removed and a replacement shell inserted.

Abstract: A method of producing a foamed thermoplastic plastics material wherein the plastics material is mixed with a pulverulent nucleating agent and is then fused in an extrusion device. A gaseous nucleating agent, generally nitrogen, is then injected into the fused mixture in an amount of from about 0.1% to 0.5% by weight. Thereafter, a liquid propellant is injected into the fused mixture in an amount of from 0.5% to 6.0%, preferably 0.5% to 5.0%, by weight. The mixture is then conveyed to an extrusion head and extruder whereupon foaming occurs.

Abstract: A method of extruding a foamed thermoplastic plastics material wherein the plastics material and a pore regulating agent are fed into an extruder and are fused in a fusion zone. The pressure of the fused material is augmented in a further zone and the material is then caused to flow past or through an obstruction so as to be converted into the form of thin layers or strands. Thereafter, steam and a propellant are sequentially injected into the fused mixture in injection zones. The steam is either saturated or superheated and has a temperature not lower than that of the mixture. The pressure of the mixture upstream of the obstruction is higher than the vapor pressure of the steam downstream of the obstruction. The pressure of the fused mixture and steam, while the propellant is being injected, is greater than the condensation pressure of the steam. The mixture is then cooled and discharged in a still further zone whereupon it foams.

Abstract: An embossing calender arrangement capable of embossing a thermoplastic plastics material film on either of its two major surfaces or both surfaces as desired, the embossing calender including two embossing roller sets. The roller sets are each mounted with their axes extending horizontally in one embodiment, in a common frame. The frame is horizontally displaceable beneath a film transfer arrangement by selectively displacing the frame and inserting the film into either one of the embossing nips defined in the roller sets or into both nips successively, the film can be embossed unilaterally on either of its two major surfaces or bilaterally without necessitating major adjustment of the arrangement.

Abstract: In an extrusion device of the type which has a screw rotating in a housing and which has a feed section in which a feed roller, cooperating with the screw, is provided, a stripper blade is used to remove the fed material from the feed roller. The present invention provides a method and an apparatus for maintaining the net force acting on the stripper blade to direct it towards the feed roller constant. To achieve this, the force of the fed material which acts in a direction tending to move the feed roller and the extrusion screw apart is measured. An opposing force is applied to the stripper blade in dependence upon the magnitude of the measured force. By so doing, the net force directing the stripper blade towards the feed roller is maintained constant.

Abstract: An apparatus is provided for the continuous coating of cylindrical workpieces with a mixture of rubber or thermoplastic plastics material. The arrangement includes an extrusion device, a coating head and a flow channel, which connects the extrusion device to the coating head. The coating head includes a hollow barrel, having a rotatable sleeve-shaped material distributor coaxially disposed therein. One or more conveyor flights are helically disposed on the periphery of the distributor. The discharge opening of the flow channel into the coating head end has a dimension corresponding to an axial pitch length of the flights on the periphery of the distributor.

Abstract: A method of extruding a foamed thermoplastic plastics material wherein the thermoplastic plastics material, together with a pore regulating agent, is introduced into an extruder and is fused. Gaseous nitrogen, in an amount of 0.2% to 0.5% by weight, and an incompletely halo-substituted hydrocarbon, in an amount of from 0.5% to 2% by weight, are sequentially injected into the fused mixture. The injected material then enters an extrusion head in which the mixture is maintained at a pressure in excess of 55 bar and the temperature thereof is maintained above a temperature pre-determined in dependence upon the nature of the plastics material. The material foams as it leaves the extrusion head.