1. Rotor speed: The faster the rotor speed, the greater the heat generation, the faster the oxidation cracking, the better the plasticizing effect, and the shorter the plasticizing time.
2. Temperature: The temperature rises, the thermal oxidation cracks quickly, and the plasticizing effect is good. However, if the temperature is too high, the rubber molecules will be excessively cracked, resulting in a decrease in physical and mechanical properties. Natural rubber debinding temperature is generally controlled at 140 ℃ -160 ℃, styrene-butadiene rubber is controlled at 140 ℃, because the temperature is too high, crosslinking or branching and other reactions will occur, but reduce the plasticity. Generally, it is not necessary to use an internal mixer for plastic mixing. At the internal mixing temperature, not only can the plasticizing effect not be obtained, but it will also lead to the formation of gel.
3. Time: The mixing of the internal mixer and the open mixer are different. The plasticity of the raw rubber increases continuously with the increase of the mixing time in the internal mixer. Therefore, the formulation of rubber mixing conditions is mainly to determine the appropriate plasticizing time according to the requirements of plasticity.
4. Glue loading and top plug pressure: too small glue loading and low plasticizing effect. If the amount of glue is too large, the raw rubber will not be evenly mixed, and the temperature of the glue will be too high. In addition, the equipment will be overloaded and easily damaged. During the plasticizer mixing process, the top plug must pressurize the rubber to ensure a good plasticizing effect. Within a certain range, the plasticizing effect increases with the pressure of the top plug.