Study On Mixing Mechanism And Experimental Rubber Planetary Continuous Mixer

Mixing is the core link in rubber processing,the quality of the compounding rubber not only affects the subsequent processing,but also,and more importantly,the performance and life of rubber products.Mixer and open mill,mainly compacting machine,is the mainstream mixing production equipment at home and abroad,but this intermittent production mode has low efficiency,high energy consumption,poor uniformity of rubber mixing and other problems.Therefore,the research on continuous and intelligent mixing technology has gradually become the mainstream direction of rubber mixing technology development.In order to solve the above-mentioned problems of the existing intermittent mixing mode,especially to solve the problem of mixing low-mooney viscosity and high-viscosity rubber,this paper develops a rubber planetary continuous mixer and its supporting mixing process system for low-mooney viscosity and high-viscosity rubber.The single-screw feeder and metering gear pump are used to transport various rubber materials to the planetary continuous mixer for continuous rubber mixing to achieve the goal of efficient,stable and low-energy continuous rubber mixing.The main work done in this article is as follows:(1)A method of mixing low-mooney viscosity and high-viscosity rubber with a rubber planetary continuous mixer was proposed,and its mixing theory was established.The planetary gear-type mixing process of the rubber planetary continuous mixer was analyzed,and the motion of the components of the planetary continuous mixer and the motion of the rubber in the planetary continuous mixer were analyzed to clarify the viscoelastic behavior of the rubber in the rubber mixing process and the transformation process of the physical state of the rubber;and the material transport principle of the planetary screw was analyzed and summarized,and the dispersion and mixing between the rubber and the filler in the rubber planetary continuous mixing process were analyzed and explained from the physical and chemical perspectives.The dispersion and mixing between rubber and filler in the rubber planetary continuous mixing process were analyzed and explained,and the mixing theory of the rubber planetary continuous mixer was initially established.(2)A set of rubber planetary continuous mixer and its supporting equipment for low-mooney viscosity and high-viscosity rubber materials was developed.With the planetary gear mixer structure as the core,we designed and optimized a single-screw feeding and conveying device and a liquid metering gear pump as the unique feeding and conveying system of the rubber planetary continuous mixer to achieve the goal of planetary continuous mixing of low-mooney viscosity and high-viscosity rubber materials,and finally designed and developed a mixing The final design and development of a rubber planetary continuous mixer with high mixing efficiency,high quality stability and low energy consumption per unit is suitable for low-mooney viscosity and high-viscous rubber materials.(3)Comparative simulation analysis of the flow field of rubber planetary continuous mixers with different number of planetary screws in the mixing process.The flow field model of the rubber planetary continuous mixer equipped with different number of planetary screws was simulated to compare and analyze the flow field of the rubber planetary continuous mixer with different number of planetary screws by pressure field distribution,shear rate distribution and mixing index distribution.The simulation results verified the mechanism of mixing action in the planetary continuous mixing process,and the accuracy of the simulation results was confirmed by comparing them with the experimental results of the best process parameters explored,which were found to be consistent with the experimental results.(4)A comparative experiment of the optimal process parameters of the planetary continuous rubber mixer was conducted to determine the optimal process parameters of the planetary continuous mixer.Through orthogonal experiments,the influence law of the change of the process parameters of the rubber planetary continuous mixer on the mixing process and the stability of the quality of the rubber compound was investigated;through the comparative analysis of the experimental data,the best process parameters of the rubber planetary continuous mixer were finally determined:the number of planetary screws was six,the speed of the central screw was 25r/min,and the mouth-shaped plate with a diameter of 60 mm..(5)A comparative mixing experimental study of the planetary continuous mixer,the twin-screw continuous mixer and the dense mixer was conducted.By comparing the experimental data on the quality stability of the rubber compound,the energy consumption of the mixing process and the quality of the rubber compound,it was found that the planetary continuous mixer produced the best quality stability of the rubber compound and the smallest energy consumption per unit,which was 76.2% of the energy consumption per unit of the mixer..To sum up,the rubber planetary continuous mixer developed and designed in this paper is a new type of continuous mixing equipment suitable for mixing and processing of low-mooney viscosity and high-viscosity rubber,which has better quality stability and lower energy consumption per unit compared with other types of mixing equipment;it fills some gaps in the field of continuous rubber mixing and provides theoretical and experimental data support for continuous rubber mixing to achieve industrial production of multiple formulations of multiple rubber materials.