Study On Mixing Mechanism, Process Simulation And Experiment Of Short Fiber-Rubber Composite Material

The short fiber reinforced material can improve the rubber property.It is the same with other powdery reinforcement padding, the short fiber can be mixed in the rubber substrate directly, but because of its special surface texture, the dispersesion is more difficult compared to the common powder material. The short fiber-rubber composite material can be mixed use the internal mixer, compares with the ordinary rubber, both must achieve the the goal of ordinary rubber mixing, and must enable the short fiber to obtain the even dispersion in the elastic substrate, this needs higher request compared to ordinary rubber mixing.Therefore, this needs the internal mixer have higher and higher performance, the shearing-meshing rotors internal mixer is precisely designed in view of this need.First, based on the mixing effects of shearing and meshing rotors, a newly designing method of synchronous rotors had been developed. The new rotors that suits the short fiber-rubber composite material mix had been developed,thus opened the prospect of the new type internal mixer which suit to mix short fiber-rubber composite material.Next, swept molding method was used by the author with the introduction of 3-D CAD. The 3-D FEM meshing models for static analysis had been built. A new way of modeling, designing and analyzing of rotors was developed by the author.Particularly, the article focuses on mixing process and mechanism, also had the simulation to the material flow field. In the cylindrical coordinate, the author had established the physical and mathematical model of short fiber-rubber composite material moving in the shearing-meshing rotors internal mixer. In different technologic conditions, the article had experimental comparisons of rotors' performance, and had got many useful data though mixing tread c ompound of all-steel radial tire by using four-wing shearing synchronous rotors,meshing rotors and the newly developed shearing-meshing rotors. The theoretical analysis and experiment results show that:1. The introduction of shearing-meshing rotors which increased filled coefficient, played down the temperature of cooling water and force of ram thrust. So the shearing-meshing rotors interal mixer can play down the request of supporting facility, reduce the cost of mixing.2. In the same technologic conditions, compared with other rotor mixer, the shearing-meshing rotor mixer had good heat transfer effect, lower dump temperature and less power consumption, suits the mixing of the short fiber-rubber composite material and some materials that are difficult to dispersed. When the rotational speed was slightly low, the property was finer, the mechanical property of rubber material was higher and the dispersion of short fiber was also higher.3. The design of shearing-meshing rotors is successful, this kind of rotor can make the short fiber reinforced material has good dispersion. It has provided the important theory and the practice basis for internal mixer's development and the short fiber-rubber composite materials' application.The results had showed that the new rotors displayed the merits of the shearing and meshing rotor, had made the flow of compound in the mixing chamber complicated and had the better capabilities of dispersion and distribution. Mixing effects and the productivity were greatly improved.