| Synchronous rotor internal mixer is the new and efficient mixing equipment developedon traditional mixer, it has high shearing strength and mixing efficiency, and with uniform andstable performance in rubber compound, therefore synchronous rotor internal mixer is widelyused in rubber industry. At present, the internal mixer is moving to large capacity with highspeed and high efficiency. The research of efficient rotor and rubber’s temperature in mixingprocess is the research emphasis of internal mixer, which has significance to improve themixing efficiency and the quality of rubber compounds. In the mixing process, rubbercompounds are got complex mechanical action by rotor and mixing chamber, besides, therubber’s temperature is changing in the mechanical action, which cause the rubber in complexmechanochemical environment. The partial excessive mixing temperature is easy to cause therubber scorching, reduce rubber’s mechanical properties and cause the unnecessary energyconsumption. Therefore, studying the mechanical effects in the mixing, analyzing temperaturedistribution and variation accurately is the difficulties in internal mixer. At present, thetemperature research in the mixing process of internal mixer in China are mainly focused onthe impact of temperature on the performance of rubber, the temperature control in the mixingprocess and simulate the temperature field by finite element method. However, the research ofthe mechanism of shearing temperature rise in the mixing process is shortage, usingmathematical model to describe the temperature change accurately in the mixing process ofsynchronous rotor internal mixer is extremely difficult, which should be further improved.In the paper, based on the basis principles of rheology, through the analysis of four wingssynchronous rotor’s configuration, calculate the rubber’s quantity of flow and distribution inthe mixing process, for the main reason that rubber heat is the influence of shearing, therefore,divided the shearing zone between the rotor and mixing chamber wall into five independentareas, using the numerical methods, establish the physical and mathematical models ofshearing temperature rise in the top and the sickle areas of wing in the mixing process ofsynchronous rotor internal mixer, and with the distribution characteristic of rubber flow,establish the model of shearing average temperature rise in the whole mixing chamber.Through the model of shearing average temperature rise, which can analyze the mechanism ofshearing temperature rise in mixing process, then analyze the relationship between the rotorconfiguration and mixing process conditions with rubber temperature rise, which can optimizethe rotor configuration and mixing process, and improve the mixing efficiency and the qualityof rubber compound. Through the mixing experiments in different process parameters, test and verify themodel of shearing temperature rise in the mixing process of synchronous rotor internal mixer.According to the experimental data, figure out the heat absorbed of rubber, mixing chamberwall and rotors, and amend the model of shearing temperature rise, then get the amendedmodel to guide the production. The amended model can accurately describe the rubber’sshearing temperature change in different areas of synchronous rotor in the mixing process.Besides, by testing the physical properties of rubber compound, according to the model ofshearing temperature rise, determine the influence of mixing temperature and shearingstrength on the performance of rubber’s properties. Experiments show that rotors do work torubber30%to50%for rubber temperature rise,48%to70%for rotors and mixing chamberwall temperature rise. When the shear rate are8.067×-10/s-1and-1.008×10-2/s-1, the rubbercompounds have better dispersion degrees of carbon black and physical properties. In themixing process of experimental four wings synchronous rotor internal mixer, the zone in thetop of wing contribution to the average temperature rise of rubber is57.6%, while the sicklezone of wing contribution to the average temperature rise is42.4%.The error of amended shearing temperature rise model between the theoreticaltemperature rise and actual temperature rise in different shearing strength of0.4%to-12.4%,the overall average error of4%. Therefore, the amended model reflects the rubber’stemperature rise in the mixing process of synchronous rotor internal mixer well, and has theguiding significance to optimize the mixing process of synchronous rotor internal mixer andimprove the mixing efficiency. |
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