Research On Principle And Testing Of Mixing And Molding For Polymer Blend

Mixing and extrusion molding have been two independent and important steps of polymer processing. With the progress of the blending technology for rubber-plastics and rubber-rubber, especially the wide use of rubber plastics blends, the traditional technical equipments can't meet the requirement of the industrial production. So new type equipment for mixing and molding of polymer blend, the mixing-molding integrative machine is developed in this paper. The equipment, on which the process of mixing and extruding can both be finished, has the advantage of both internal mixer and extruder. The following research work on this equipment has been done:1. The new type mixing-molding integrative machine with novel rotor configuration was designed. Both the hydraulic drive and the mechanical drive, together with the stepless speed regulation of rotor and s, are available in this machine to get the good mixing properties. As a result, the feedstock of internal mixer can match well with the discharge of the extruder. The most important thing of the machine is that both mixing and molding can be finished on it, for which the process from raw material to product can be finished by one set of machine.2. The thorough study on the rotor configuration and the mixing theory was made. The stress and movement mode of the compound when mixed and discharged were analyzed. And the mathematical equation of mixing theory is set up for the mixing-molding integrative machine, which can be used to verify the computer simulation result of fluid field.3. The extrusion molding theory was thoroughly studied. With the discharge rubber compound temperature above 100℃, the compound is in the state of viscous fluid. So it was according to the extrusion theory for viscous fluid that the mathematical equation of the relation between extrusion production capacity and other parameters for this machine is concluded in this paper.4. According to the production capacity of internal mixer and extruder, together with it's influence factors, the mathematical equation for the continuous process of mixing and molding was set up, which can act as the theoretical basis of the experimental research.5. The finite analysis of the fluid field in the process of mixing and molding was performed with the help of ADINA. The result of the analysis proves that the stress analysis of the rubber compound, together with the physical and mathematical models, is correct, which supply the basis of the following experimental research.6. Three rotors with different configuration were designed and 500 contrast experiments for the designed rotors and traditional rotors were performed. At the same time, the optimum process condition for the rotors and the optimum process parameters for the mixing process were discussed in this paper. The analysis result shows that functional two-wing synchronous rotors are best for the mixing effect and the pinned two-wing synchronous rotors are the second, which also proves that the connecting theory analysis is correct.7. The experimental research of the mixing-molding integrative machine verifies and improves the mathematical model of the continuous mixing and molding. The testing result of the machine proves that its processing properties are reliable, which sets the basis for the popularization and application of the machine.8. The engineering mathematical model was set up for the functional two-wing synchronous rotors with the help of the quadratic regression cross method. And the predictive value and the experimental value were compared, which showed that the precision of the forecasting model was very good. So the model can be used to predict and analyze the mixing process for the new type mixing-molding integrative machine.The theory research, the flow field simulation, and the experimental research in this paper all show that the developed mixing-molding integrative machine is feasible. The flow field simulation and the experimental research show that the mixing and molding principle and the continuous process theory, which was set up in this paper, are correct and useful for the development of the industrial equipment.