A continuous kneading device (1) includes a pair of kneading rotors (3), being capable of increasing mesh between the kneading rotors (3) while suppressing a kneading load applied to the kneading rotors (3). The continuous kneading device (1) includes a barrel (2) and a pair of kneading rotors (3) housed in the barrel (2) and rotating in mesh in directions different from each other. Each kneading rotor (3) includes a plurality of kneading flights (11, 15) for kneading a material supplied into the barrel (2). The kneading flights (11, 15) and respective portions of the barrel (2) housing the kneading flights (11, 15) respectively configure a plurality of kneading sections aligned axially of the kneading rotors (3). The material is fed axially from the upstream kneading section to the downstream kneading section to be sequentially kneaded. The kneading flight (15) constituting the downstream kneading section has a rotational outer diameter (D2) larger than a rotational outer diameter (D1) of the kneading flight (11) constituting the upstream kneading section.

An Extruder for providing a flow of viscoelastic material such as rubber is disclosed herein. The extruder includes several zones (A, P, H, S), each assigned to a particular rheological function and arranged axially from an upstream end to a downstream end of the extruder and having an endless screw of given diameter (D). In each of the zones, at least one helicoidal flight extends radially from a central shaft of the screw over a height (h.sub.1), in a direction and with a pitch which are defined for each of the zones, and which is rotationally driven about an axis (XX) in a barrel. The barrel is provided with various structures to further assist with the flow of the viscoelastic material

A self-sealing elastomer composition that includes a diene elastomer, a hydrocarbon resin with a given softening temperature, and a liquid plasticizing agent, is manufactured according to a process that includes successive stages. In one stage, the hydrocarbon resin is incorporated in the diene elastomer by kneading the resin and the elastomer in a mixer at or up to a temperature referred to as hot compounding temperature, which is greater than the softening temperature of the resin, in order to obtain a masterbatch. In another stage, the liquid plasticizing agent is incorporated in the masterbatch by kneading the agent and the masterbatch in the same mixer or in another mixer, in order to obtain the self-sealing composition. The self-sealing composition then is formed dimensionally.

An extruder for the viscosity-increasing preparation of meltable polymers, wherein an extruder screw with at least one helical extruder screw flight is positioned in a housing having an inner housing recess. A diameter central region has a larger outer diameter than at least one of the other diameter regions, and a conical transition is formed in each case between regions of different diameters. Two degassing zones are provided in the diameter central region, each of which has at least one associated suction opening in the housing, one degassing zone being designed in the region of the satellite screws and an additional degassing zone being designed upstream thereof in the flow direction. The thread depth of the screw threads, formed between the extruder screw flights is greater in both degassing zones than in at least one sealing and compression section formed therebetween.

An extruder for the viscosity-increasing preparation of meltable polymers, wherein an extruder screw with at least one helical extruder screw flight is positioned in a housing having an inner housing recess. A diameter central region has a larger outer diameter than at least one of the other diameter regions, and a conical transition is formed in each case between regions of different diameters. Two degassing zones are provided in the diameter central region, each of which has at least one associated suction opening in the housing, one degassing zone being designed in the region of the satellite screws and an additional degassing zone being designed upstream thereof in the flow direction. The thread depth of the screw threads, formed between the extruder screw flights is greater in both degassing zones than in at least one sealing and compression section formed therebetween.

The application relates to a plasticizing unit with a cylinder and a screw that is rotatably mounted in the cylinder and has a screw section which is designed as a shearing section and in which a blocking web encircling the screw core in a helical manner and a main screw thread enclosed by the blocking web are provided. A shearing web runs in the main screw thread parallel to the blocking web at a lower height than the blocking web. In this manner, two screw threads are produced which run parallel to each other and are separated by the shearing web. The threads are designed in the form of wave screw threads. Each wave screw thread is equipped with one or more wave peaks with a surface which is designed in the form of a plateau and forms a wave peak shearing surface, wherein the wave peak shearing surface is located at the same height as the surface of the shearing web in the region. The shearing web surface section which lies in the region of a wave peak shearing surface constitutes a shearing web sharing surface. A wave peak shearing surface and a shearing web shearing surface together form a total shearing surface. A specified total shearing surface together with the inner wall of the cylinder forms a shearing gap in accordance with a shearing gap size specified for the total shearing surface.

The application relates to a plasticizing unit with a cylinder and a screw that is rotatably mounted in the cylinder and has a screw section which is designed as a shearing section and in which a blocking web encircling the screw core in a helical manner and a main screw thread enclosed by the blocking web are provided. A shearing web runs in the main screw thread parallel to the blocking web at a lower height than the blocking web. In this manner, two screw threads are produced which run parallel to each other and are separated by the shearing web. The threads are designed in the form of wave screw threads. Each wave screw thread is equipped with one or more wave peaks with a surface which is designed in the form of a plateau and forms a wave peak shearing surface, wherein the wave peak shearing surface is located at the same height as the surface of the shearing web in the region. The shearing web surface section which lies in the region of a wave peak shearing surface constitutes a shearing web sharing surface. A wave peak shearing surface and a shearing web shearing surface together form a total shearing surface. A specified total shearing surface together with the inner wall of the cylinder forms a shearing gap in accordance with a shearing gap size specified for the total shearing surface.

A multi-shaft extruder which has screw shafts which are rotatable in the same direction and at the same speed, and which has at least one gas venting opening, and which has, in the entry region of said at least one gas venting opening, screw elements with a particularly large pitch or screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft. The invention also relates to the use of the extruder according to the invention for processing or manufacturing plastic materials, and to the use of the screw elements with a particularly large pitch or the use of screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft, in the region of the gas venting opening of a multi-shaft extruder.

A multi-shaft extruder which has screw shafts which are rotatable in the same direction and at the same speed, and which has at least one gas venting opening, and which has, in the entry region of said at least one gas venting opening, screw elements with a particularly large pitch or screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft. The invention also relates to the use of the extruder according to the invention for processing or manufacturing plastic materials, and to the use of the screw elements with a particularly large pitch or the use of screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft, in the region of the gas venting opening of a multi-shaft extruder.

A high shear mixing unit includes a mixing screw and a housing receiving the mixing screw; wherein the housing includes a nozzle provided at a distal end and a hopper in communication therewith, and wherein the mixing screw includes a rotating shaft and blades provided on an outer surface of the rotating shaft, wherein the rotating shaft has a first tapered portion having a gradually increasing outer diameter in a direction toward the nozzle, a kneading portion having a uniform outer diameter or a gradually increasing outer diameter in a direction toward the nozzle, and a second tapered portion having a gradually decreasing outer diameter in a direction toward the nozzle, in this order, and the blades comprise first spiral blades disposed on an outer surface of the first tapered portion, second spiral blades disposed on an outer surface of the kneading portion, and third spiral blades disposed on an outer surface of the second tapered portion, thereby providing a high shear mixing unit.