Dynamic Simulation And Expreimental Study Of Rubber Distribution Mixing Process

Rubber mixing is the core process of the processing technology of rubber products,which directly affects the quality and life of rubber products.In addition to formulation,mixing equipment and mixing process affect the quality of rubber mixtures.There are distribution mixing and dispersion mixing in the process of rubber mixing.Dispersion mixing effect can be described and assessed by carbon black dispersion,distribution mixing effect can be described and assessed by uniformity of distribution of carbon black and other complexes in rubber.Both of them are equally important.Therefore,it is of great significance to study the mixing process of rubber distribution.Based on the viscoelastic solid theory of rubber mixing,the dynamic process of rubber distribution mixing is simulated by the discrete element analysis software EDEM.The simulation results are analyzed.The reliability of EDEM simulation of rubber distribution mixing is verified by comparing the experimental results with the simulation results.The main work accomplished in this paper is as follows:1.By consulting a large number of literature and combining with the characteristics of rubber distribution mixing process.The simulation analysis of rubber distribution mixing process is carried out by using the discrete element method.Furthermore,the calculation theory of rubber distribution mixing based on this method is deduced.2.The computational model of rubber distribution mixing process is established.Rubber and carbon black particles were used,the soft sphere model is used for both kinds of particles,which adopt Hertz-Mindlin with JKR Cohesion model as contact model-The JKR parameters are determined by experimental calibration.And the movement mode of the model is set up.3.The model is calculated and the simulation results are analyzed.The material movement form,material pressure field distribution,velocity field distribution and particle mixing degree in the mixer are studied.The mixing effects of particles with different rotational speeds,filling ratios and rotor configurations are simulated.The simulation results show that the mixing effect of wide-edged rotor is better than that of synchronous four-edged rotor when the rotational speed of synchronous four-edged rotor is 80?and the filling coefficient is 0.65.Under the same conditions,the mixing effect of wide-edged rotor is better than that of synchronous four-edged rotor.4.The experiment is carried out on the same/different bidirectional composite shear rotor mixer experimental platform in the laboratory.When the rotor speed is 60 ?,80 ?,100 ? and the filling coefficient is 0.55,0.65 and 0.75,the experimental results are in good agreement with the simulation results,which proves that the EDEM simulation method is reliable.5.According to the results of EDEM simulation of rubber mixing,the rotor structure was designed.The angle between the farthest point of the wide-edged rotor and the nearest point of the distance between the wide-edged rotor and the wall of the internal mixing chamber is determined to be 96°;In addition,it is verified that the mixing effect of wide-edged rotor is better than of synchronous four-edged rotor.