This mixing process is to add all the compounding agents except the operating oil (and of course, the vulcanizing agent) at the beginning of the mixing, and have sufficient input power to mix it to 1 to 2 Mix, disperse and distribute in minutes. At this time, the temperature in the mixer reaches 130-140 degrees, and then choose a rate that can maintain and slightly adjust the mixing effect, and start to inject the operating oil. This method was once widely used in the one-stage mixing of tire compounds, and at the same time, it obtained high output and good carbon black dispersibility. This method is currently not popular because the high structure carbon black can be dispersed without the presence of process oil.
Ethylene-propylene rubber is mixed on an internal mixer. It is easy to prepare rubbers by standard mixing or reverse order mixing. However, when the filler and plasticizer are relatively large, the reverse order mixing method is most suitable. If possible, try to reduce the number of times the mixer is fed, because too many times will affect the dispersion and extend the mixing time. Mixing ethylene-propylene rubber in the mixer can be completed in a short time. When mixing masterbatch without vulcanizing agent, the mixing cycle is generally 3 to 5 minutes, and the discharge temperature is generally 120 to 150 degrees. When rubber compound containing vulcanizing agent and accelerator is mixed, it is generally 4 to 6 Minutes, discharge temperature does not exceed 110 degrees (sulfur, accelerator system) or 120 degrees (peroxide system). In order to obtain the best mixing effect, for low Mooney viscosity or low hardness ethylene-propylene rubber mixing, it is recommended that the loading amount of each vehicle should be increased by 10-15% than the calculated value; otherwise, for high Mooney viscosity When mixing high-hardness rubber, the loading of each car should be 5-10% lower than the calculated value. To get the best dispersion effect and production efficiency match.