Study On The Mixing Mechanism And Experiment Of Short Fiber-Rubber Composite Material

In recent years, the short fibber-rubber composite material which is a new type polymeric material has been developed with the development of Polymeric Materials Science. And the requirements of polymeric materials have been becoming more and more, the qualities of polymeric materials have been becoming better and better. The short fiber-rubber composite material is the best choice for producing tires. The rubber mixed with short fiber would promote the performance of tires, such as low-rolling resistance, high-wearing feature and so on. In the process of short fiber-rubber composite material preparation, mixing is essential. But the short fibers are easy to aggregate, so the mixing process should make the short fibers disperse well in the rubber, and most of all should protect the short fibers not be destroyed. Otherwise, the short fiber-rubber composite material is useless. So, the mixing equipment—internal mixer must have good performance. As is well known, the rotors are the most important factors of internal mixer performance. So the research and study on internal mixer, as a matter of fact, is on rotors. And all jobs of the thesis are just on the base of special mixing requirement of short fiber-rubber composite material.Firstly, the mixing mechanism and characteristic of short fiber-rubber composite material have been analyzed comprehensively referring to a number of documents and patents about that from home and abroad were consulted. As a result, a new type of six-wing varying clearance synchronous rotor has been designed to satisfy the mixing requirement of short fiber-rubber composite material. The design of new type of six-wing rotor referred to the theory of internal mixer design and theory of Mckelvey and Funt. The clearances between wings top and mixing room are different is the characteristic of the new type rotor. And the different clearances would have big enough shearing force to disperse the short fibers and other additives, but importantly, the bigger clearance could protect short fibers not to be destroyed. So the mixing process of the new type of six-wing varying clearance synchronous rotor could guarantee the quality of gross rubber.Secondly, in order to analyze the structure and flow field of the new type rotor, the ADINA software was chose. But the hardware model of the rotor is necessary for the process of ADINA analysis. So, during the design of the new type sing-wing varying clearance synchronous rotors, the 3D technology was used and the hardware model of the rotor was made by using Pro-Engineer and choosing scanning method. Through the structure analysis by ADINA, the displacement and stress of the rotors could be well-judged. And the situation of rotors'structure analysis incorrectly using the traditional way of mechanical analysis has been changed. Through the flow field analysis result by ADINA, the status of the rubber mixed in internal mixer could be judged. Therefore, the strength and structure of the rotors would be analyzed fast by using ADINA. And alter the design of rotors in time. So, the efficiency of rotors'design can be increased.Lastly, the experiments of the new type six-wing varying clearance synchronous rotor were studied. At first, through the comparison of the rotors designed and other two pair rotors at the same experimental conditions, the conclusion of the new type six-wing varying clearance synchronous rotors could get better quality gross rubber has been drawn. The short fibers and other additives dispersed well in the rubber, and the physical and mechanical properties of the gross rubber are perfect. Also, through the experimental result of the rotors designed at different experimental conditions, the conclusions which could be drawn as such, the short fibers mixed with rubber should at the appropriate proportion, the physical and mechanical properties of the gross rubber would decrease if the short fibers added too much. Also, the experimental conditions influence the quality of short fibber-rubber composite material, such as fill factor, rotors'speed, ect. The good choice of the experimental conditions is 0.6 for the filled coefficient, 0.6Mpa for the ram pressure, 40℃for the cooling wanter temperature and 70rpm for the rotors'speed.