Abstract An extruder, adapted in a preferred form to provide additional mixing to a mass of material such as rubber or plastics preliminarily mixed in means such as an intensive high shear mixer. The extruder includes a body having a bore therethrough, with a feed opening at one end and a discharge opening at the other end, a screw disposed therein substantially coextensive therewith and having a primary flight extending substantially the full length thereof and means for rotating said screw in said cylinder, said screw and body being divided into a feed section, compression section, mixing section and (in a preferred embodiment) a discharge section. Said compression section is disposed between said feed section and said mixer section. Said mixer section screw includes a secondary independent blending flight, and said screw is adapted with a high shear section intermediate said mixing section and said discharge opening.
A mixing extruder for the processing of rubber, plastics and like materials having a housing with a generally cylindrical bore therein and a rotor rotatably mounted in the bore, the bore having a feed opening and a discharge opening at opposite ends thereof, comprising: a. a primary helical flight fixed to said rotor and substantially coextensive therewith, said primary flight forming a helical channel for the movement of material in the bore; b. a portion of the extruder forming a feed section which communicates with the feed opening and in which the bore and rotor are of relatively enlarged diameter; c. a portion of the extruder forming a compression section which communicates with the feed section and in which the diameter of the bore and rotor linearly diminishes as the material progresses from the feed section; d. a portion of the extruder forming a mixing section which communicates with the compression section and in which a secondary helical flight is fixed to the rotor intermediate the primary flight, said secondary flight being shaped to mix the material as it passes through the helical channel of the primary flight; e. a portion of the extruder forming a shearing section which communicates with the mixing section and in which a shear collar is removably secured to the rotor to create a shearing force on the material as it progresses through the channel of the primary flight; and f. a portion of the extruder forming a discharge section which communicates with the shearing section and with the discharge opening and which is of sufficient length to avoid the transmission of back pressures through the extruder.
Claim 2
Dependent Claim
272 words
A mixing extruder for the processing of rubber, plastics and like materials having a housing with a generally cylindrical bore therein and a rotor rotatably mounted in the bore, the bore having a feed opening and a discharge opening at opposite ends thereof, comprising: a. a primary helical flight fixed to said rotor and substantially coextensive therewith, said primary flight forming a helical channel for the movement of material in the bore; b. a portion of the extruder forming a feed section which communicates with the feed opening and in which the bore and rotor are of relatively enlarged diameter; c. a portion of the extruder forming a compression section which communicates with the feed section and in which the diameter of the bore and rotor linearly diminishes as the material progresses from the feed section; d. a portion of the extruder forming a mixing section which communicates with the compression section and in which a secondary helical flight is fixed to the rotor intermediate the primary flight, said secondary flight being shaped to mix the material as it passes through the helical channel of the primary flight; e. a portion of the extruder forming a shearing section which communicates with the mixing section and in which a shear collar is removably secured to the rotor to create a shearing force on the material as it progresses through the channel of the primary flight; and f. a portion of the extruder forming a discharge section which communicates with the shearing section and with the discharge opening and which is of sufficient length to avoid the transmission of back pressures through the extruder.