An internal continuous mixer with parallel mixing rotors and a screw controlled discharge. Each rotor comprises a central bladed mixing portion, a screw infeed portion and a screw outfeed portion. The threads of the screw outfeed portion have nonuniform crest diameter thus working the material being mixed, and providing clearance permitting the material discharge rate to be controlled down stream therefrom as by an enclosed material conveyor or feed screw, preferably a screw extruder apparatus.
RELATED APPLICATIONS
This application is a continuation-in-part of our co-pending application, Ser. No. 841,349, filed July 14, 1969, the disclosure of which is incorporated herein by reference.
Continuous mixers of plastic materials are equipped with greased journal bearing assemblies instead of bulky, expensive, pumped circulating-oil lubricating systems, usually involving oil-cooling heat exchangers with circulating water. Such pumped oil systems having traditionally been employed in the past for lubricating journal bearings of the two rotors in such mixers. Novel thermal isolation of the journals for the two rotors separates their bearing assemblies from the severe heat being generated during mixing of plastic materials by continuous rotation of the two rotors within the mixer barrel. Localized cooling provides heat sinks for the drive and driven journals of each rotor. The rotors are shown as three-piece assemblies with drive and driven journals separate from the main rotor body. Beneficial interactions of localized cooling for the drive and driven journals plus thermal isolation of the journals from the severe heat being generated in the mixer barrel advantageously enables the journal bearing assemblies to be lubricated by grease instead of by circulating oil. Each of the journal bearing assemblies shown and described comprises two axially spaced, spherical-type roller bearings each encircling a portion of a journal and each being equipped with a seal housing having a grease fitting. The outer races of these roller bearings are shown and described as mounted in respective end frames which are spaced farther away from the upstream and downstream ends of the mixer barrel than their usual spacing in the past.
An object of the present invention is to provide a kneading and extruding machine which includes a screw type two-shaft kneader and a gear pump in which the degree of kneading melted resin material can be made uniform at the discharging port of the screw type two-shaft kneader. In the kneading and extruding machine of the present invention, the height of scraping flights or inverse flights of the screw in the discharging section of the screw type two-shaft kneader is determined to be an average of the inner diameter of the cylinder and the bottom diameter of the groove of the screw at the most.
An object of the present invention is to provide a kneading and extruding machine which includes a screw type two-shaft kneader and a gear pump in which the degree of kneading melted resin material can be made uniform at the discharging port of the screw type two-shaft kneader. In the kneading and extruding machine of the present invention, the height of scraping flights or inverse flights of the screw in the discharging section of the screw type two-shaft kneader is determined to be an average of the inner diameter of the cylinder and the bottom diameter of the groove of the screw at the most.
