It is mainly used for plasticizing and mixing of rubber. It has one more mixing chamber than an open mixer (Figure 1). After the raw rubber and compounding agent are loaded into the mixing chamber from the feeding hopper, the material door is closed, and the upper plug of the material pressing device is pressed down, and the two rotors in the mixing chamber are rotated at different or the same speed. The loaded rubber is subjected to occasional stirring, rolling and kneading between the rotors, the rotor and the mixing chamber, resulting in oxidative chain breaks and increased plasticity. At the same time, the rubber material is dispersed and uniformly mixed due to the shearing effect, so as to achieve the purpose of making rubber. Since the invention of the elliptical rotor closed rubber mixer in 1916, the closed rubber mixer has been rapidly developed in the rubber industry, and then other types of closed rubber mixers have been presente