TRANSFERMIX PLANT AND EXTRUDER Russian patent published in 1999 - IPC

FIELD: rubber industry. SUBSTANCE: plant has first member with inner working surface provided with spiral thread and second member arranged in first member. Second member has outer workings surface provided with spiral thread of different hand of helix but coaxial with spiral thread of first member. Spiral threads pointed to each other form passage for machined material. Plant has enveloping surface passing through highest points of inner thread and located inside volume limited by enveloping surface passing through highest points of outer thread widening until enveloping surfaces coincide. Areas of cross-sections of grooves of threads pointed to each other are made varying in opposite directions between maximum and minimum values for each thread practically along one axial length of passage. Spiral thread with decreasing cross-section of groove has least two starts. First start on part of axial length decreases in groove section at rate smaller than second start. First start on other part of axial length decreases in area of cross-section of its groove quicker second start. Extruder has rotor installed in cylinder to form in starting section a transfermix section as zone of plasticization for extruded material. Extruder has discharge section. Rotor has outer spiral thread. Cylinder in transfermix section has inner spiral thread with opposite direction of helix but coaxial with rotor thread. Extruder has enveloping surface of two threads with radial clearance. Rotor thread changes from full cross-section to zero cross-section on axial length of transfermix section. Cylinder thread changes from zero cross-section to full cross-section and inversely on any following length of transfermix section. Spiral thread of feed member has at least two starts. First start on part of length of transfermix section does not decreases initially in cross-section of groove. Second start decreases on this part of length. Second start on other part of transfermix section length preserves its minimum cross-section of groove, and first start decreases in cross-section of groove. Transfermix-type plant makes it possible to mix, machine and homogenize components with additional longitudinal mixing, reducing duration of machining cycle. Extruder provides grinding of rubber waste and obtaining clean rubber particles varying in size and other characteristics. EFFECT: enlarged operating capabilities. 12 cl, 6 dwg