Simulation Analysis And Experimental Study On Refining Process Of The Rubber Deslfurization In The Co-rotating Multi-screw Extruder And The Mixing Mill

As a substitute for rubber parts,reclaimed rubber(RR)can produce various rubber products,because of its excellent processing performance and low price,it is widely used in our country.After ground tire rubber(GTR)'s continuous desulfurization,refining process should be carried out to prepare reclaimed rubber,to improve the desulfurization rubber(RD)'s processing performance,lower products' mooney viscosity.The traditional refining equipment is refiner(open mixing machine),this method has been used in China for decades,there are many disadvantages in the production process,such as serious pollution,high safety risk,strong labor intensity and so on,it has become difficult to adapt to modern production.In view of the above situation,a new idea of using co-rotating multi-screw extruder to extrude RR in RD was put forward.Compared with the traditional refining equipment,the multi-screw extruder can also has ability to apply shear reinforcement on RD,in the process of desulfurization,the desulfurization powder is mixed and homogenized to increase its fluidity.At the same time,co-rotating multi-screw extruder has the advantages of continuous,high efficiency extrusion,green,energy saving and so on.In this paper,three refining equipment as the research object,influence on the shear flow field distribution and the process parameters are studied,to provide a theoretical basis for the process parameters with multiple screw extruder settings.In this paper,the rheological properties of RD were investigated,and the shear flow field of RD was simulated and calculated according to the physical model of three kinds of refining equipment.Through the comparative analysis of the shear rate,shear stress,their weighted average,and strain distribution,three kinds of shear flow field distribution characteristics of refining equipment,and explored the screw speed and production's effect on lowering Mooney of twin screw extruder.Then,the simulation results are tested with three kinds of refining equipment's production experiments.The simulation results show that the shear rate and shear stress distribution of multi-screw extruder are more uniform and the weighted average value is larger,however,the cumulative strain distribution range of the particles in the multi-screw flow field is wider,and the uniformity of the extruded product is not as good as that of the refiner.For the co-rotating multi-screw extruder,reducing the production or increasing the screw speed can promote the flow field to enhance the shear effect.The experimental results show that there is no difference in mechanical properties between RD and RR,the latter has a lower Mooney viscosity and improved processing performance.The same effect as the refiner and the co-rotating multi-screw extruder is comparable to the refining effect.According to the experimental results and simulation analysis,then taking the various advantages of co-rotating multi-screw extruder in the refining process into account,it is concluded that the refining effect of the co-rotating multi-screw extruder is better,and it has great prospects for development.