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Several factors affecting rubber mixing quality of internal mixer by rubber machinery

Several factors affecting the quality of rubber mixing in internal mixers:
  1. Rotor structure and type: The geometry and size of the rotor working surface largely determine the production capacity and mixing quality of the internal mixer.
   There are two basic configurations of internal mixer rotors: shearing type rotors and meshing type rotors. Generally speaking, the shear-type rotor internal mixer has higher production efficiency, and can quickly feed, mix and discharge glue quickly. The intermeshing rotor internal mixer has the characteristics of high dispersion efficiency and low heat generation rate, and is suitable for the manufacture of hard rubber materials and one-stage mixing. The dispersing and homogenizing effect of the intermeshing rotor internal mixer is better than that of the shearing rotor internal mixer, and the mixing time can be shortened by 30-50%.
  2. Speed: Increasing the speed of the internal mixer rotor is one of the most effective measures to strengthen the mixing process. The speed is doubled, and the mixing cycle is shortened by about 30%~50%. Increasing the speed will accelerate the heat generation, resulting in a decrease in the viscosity of the rubber compound and a decrease in the mechanical shearing effect, which is not conducive to dispersion.
3. Mixing temperature: high mixing temperature is beneficial to the plastic flow and deformation of the raw rubber and rubber compound, and is beneficial to the wetting and mixing of the surface of the solid compounding agent particles by the rubber, but it also reduces the viscosity of the rubber, which is not conducive to Crushing, dispersion and mixing of compounding agent particles. Excessive mixing temperature will also accelerate the thermal oxidative aging of rubber and reduce the physical and mechanical properties of vulcaniz Cooling measures; but the temperature should not be too low, otherwise the rubber material will be scattered.
  4. Mixing time: Under the same conditions, the mixing time required for mixing rubber materials with an internal mixer is much shorter than that of an open mixer. When the mixing quality is required to be constant, the required mixing time will be shortened with the increase of the internal mixer speed and the pressure of the top plug. Improper feeding sequence and unreasonable mixing operation will prolong the mixing time. Extending the mixing time can improve the dispersion of the compounding agent in the rubber compound, but it will also reduce the production efficiency. Excessive mixing time will easily cause over-mixing of the rubber compound and damage the physical and mechanical properties of the vulcanizate. It will also cause the "thermal history" of the rubber compound to increase and scorch is likely to occur. Therefore, the mixing of the rubber compound should be shortened as much as possible. Practice time.



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