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: 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: 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: The invention relates to a multiple extrusion head for the production of profiles, in particular for tire production, with a fixedly arranged head flange, into which extruders open, and with a closed head having flow ducts, an adapter and a profile strip, which closed head is arranged so as to be capable of being braced against the head flange and of being pivoted away. The invention is defined in that the closed head has a receptacle which is open in the direction of the head flange and in which at least one open flow duct insert is removably arranged.

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: An adjusting device for the rolls of a calender having a hydraulic drive for the fine setting of the rolls in their working position and a hydraulic drive for positioning the rolls in the working, maintenance and roll-change positions. The hydraulic drive for positioning the rolls includes hydraulic cylinders having double-acting pistons. An interlock device is provided, by which the piston rod can be interlocked positively in the working position of the rolls, after which the piston rod can be acted on by a prestressing force opposed to the adjusting direction in such a way that the interlock has no play.

Abstract: In a process and apparatus for producing TPE foam profiles, material is heated up in a conveying zone at a temperature of 180.degree.-210.degree. C. and a pressure of 100-200 bar. The melt then passes through a two-stage shear process consisting of two spaced shearing sections separated by a homogenizing section in which the melt and water are intimately mixed, with the melt being exposed to a further homogenizing section in which the melt is intensively mixed and homogenized prior to being extruded through a profile die.

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

Abstract: The invention relates to a polishing stack with at least one fixed and one moveable polishing roll for polishing a plastic sheet leaving a wide extrusion die. A device is provided that preloads the frames and the bearings and acts on a roll gap adjusting device which includes a pinion gear arrangement and drive for finely adjusting the roll gap between the fixed and moveable rolls. The polishing stack in preferred form includes a center fixed roll and top and bottom adjustable rolls.

Abstract: A continuous material press for the production of material sheets made of substances which require a high pressure and an intensive thickness reduction during the pressing process, with the press including a heated/cooled and driven central drum, and a circulating endless steel belt tensioned around the central drum, with the material to be pressed being guided and pressed between the shell surface of the central drum and the steel belt. An additional stationary pressing device comprised of elastic steel belt sections is located outwardly of the endless steel belt and is mounted in tension to variably increase the pressure on the endless steel belt and thus on the material. An opening is formed in the steel belt section mounted in which is a pipe for delivering compressed air or water vapor to interface on the endless steel belt and the stationary steel belt section, the compressed air or water vapor forming a lubricating film for reducing friction.

Abstract: The invention relates to a process for a uniform and fast heating of products by microwaves that are pulsed and introduced intermittently into the products, with the products to be treated, such as chemical or pharmaceutical products or foodstuffs, particularly ready-cooked meals, being conveyed by a continuously working endless conveyor belt through a treatment chamber in open or closed microwave-permeable trays and with the treatment chamber being equipped with microwave generator supply channels that are arranged in a vertical or inclined position relative to the conveyor belt. The line is operated at a microwave power profile that shortens the build-up time and breaking time of the microwave pulses, at a working frequency of 50 kHz that has an edge steepness of 2 microseconds, and with pulses the amplitudes of which have a rectangular form and the length of which is in the microseconds or milliseconds region.

Abstract: The invention is directed to a method and an arrangement for continuously producing a rubber base compound and a rubber end compound in a single stage for vehicle tires, drive belts, conveyor belts as well as for industrial rubber products. The rubber base compound and the rubber end compound are produced continuously in one and the same mixing arrangement which includes a twin-screw extruder.

Abstract: The present invention relates to an apparatus for producing a controllable, uniform conveying pressure for processing highly viscous, temperature sensitive rubber or thermoplastics, consisting of two rotating conveying elements that form a toothlike sealing profile and are arranged on shafts in a housing. The root diameter of the conveying elements more or less corresponds to the diameter of the shaft sections that are axially adjacent to the conveying elements on either side and form bearing surface therefor. The radial faces of the conveying elements are thus avoided and so are the usually rather difficult sealing problems at these faces. By additionally providing either the shaft sections or the surrounding housing parts with return channels the channel volume of which decreases in the conveying direction, the axial sealing capacity of the gear pump is improved considerably.

Abstract: A continuously operating material press comprising temperature-controllable and drivable central drum 1 and a tensioned endless steel belt which passes around a major portion of the surface of the central drum and is supported by at least two guide drums and a tensioning drum. An increase in the pressure acting on a strip of material which is guided between the steel belt and the surface of the central drum is achieved by providing an additional pressing means which comprises a roller chain and an additional high-tensile steel belt supported by the chain. Both the roller chain and the additional steel belt are connected to a support structure for the central drum either directly or through the intermediary of tensioning devices.

Abstract: The invention is directed to a method and an arrangement continuously producing a rubber base compound and a rubber end compound in a single stage for vehicle tires, drive belts, conveyor belts as well as for industrial rubber products. The rubber base compound and the rubber end compound are produced continuously in one and the same mixing arrangement which includes a twin-screw extruder.

Abstract: The invention relates to an apparatus for producing a controllable, uniform conveying pressure for processing highly viscous, temperature sensitive rubber or thermoplastics material. The apparatus includes two rotating conveying elements that conjointly form a tooth-like sealing profile and that are arranged on respective shafts in a housing. The root circle diameters of the conveying elements more or less correspond to the diameters of the shaft sections axially adjacent to the conveying elements. For this reason, the radial end faces of the conveying elements are avoided and so are the difficult sealing problems which would otherwise be present at these end faces. The shaft sections adjacent the conveying elements guide and keep the toothed profiles in alignment with each other as they rotate to convey the material.

Abstract: An exact distance between the rotating knives and the stationary die plate of a pelletizer can be set and maintained during the entire pelletizing process. The drive shaft for the cutting beams and cutting knives can be heated or cooled and is supported on the knife side in a mobile bearing. As a result of the heating/cooling of the shaft, the shaft is allowed to extend through the mobile bearing in the direction of the knife head, whereby the distance between the die plate and the cutting knives rotating above the plate can be adjusted precisely and within the My range.

Abstract: The invention relates to an apparatus for producing monodisperse powdered rubber and includes an extruder and individual conveying, grinding and discharge sections with respective cooling units corresponding thereto. The cooling units are arranged outside of the extruder and receive the grinding stock after each grinding process in order to cool and transport the stock to the feed opening of the following conveying, grinding and discharge section of the extruder.

Abstract: A process for the continuous production of a rubber compound in a twin-screw extruder is disclosed that improves the dispersion of carbon black in the extrudate while reducing the specific energy requirements of the extrudate. Rubber is fed into the extruder together with a processing aid and masticated up to a temperature of 120.degree. C. to 180.degree. C. Subsequently, a first part of carbon black representing preferably 40% to 80% of the whole quantity of carbon black is fed into the heated extrudate. Afterwards, plasticizing oil is added to the extrudate before the second remaining carbon black part is fed and incorporated into the extrudate at a temperature of 120.degree. C. to 180.degree. C. The whole compound is then cooled, a crosslinking agent is added, and the compound is homogenized and extruded.

Abstract: An extruder for poorly miscible extrudates which includes a pin-lined barrel section and a transfer mixing section used together. Restricting pins are arranged in the transfer mixing section in the region of the greatest barrel channel volume and permit universal use of the extruder with respect to the extrudate. The combination of the two 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 a halving of the drive torque. Due to a constant number of channels of the barrel channels and screw channels, the number of barrel flights and screw flights remains independent of the channel cross-sectional area of barrel and screw. A helical barrel groove in the feed zone of the extruder barrel additionally improves the mixing quality of the extrudate and the output of the extruder.