Influencing factors of internal mixer

That is, the mixing capacity, insufficient capacity will reduce the shearing effect and kneading effect on the rubber material, and even the phenomenon of rubber material slipping and rotor idling, resulting in poor mixing effect. On the contrary, the capacity is too large, the rubber material is difficult to turn over, so that the upper top bolt is not properly positioned, so that a part of the rubber material is retained at the neck of the feeding mouth, so that the rubber material is not evenly mixed, the mixing time is long, and the equipment is easily overloaded and the energy consumption is large. Therefore, the mixing capacity should be appropriate, usually 60% to 70% of the total effective volume of the closed chamber. The mixing capacity of the internal mixer can be calculated by the following empirical formula: Q-loading capacity, Kg; K-filling factor, usually 0.6~07; V -- Total effective volume of closed chamber, L; ρ -- Density of compound, g/cm3. The selection and determination of filling coefficient K should be determined according to the type of raw rubber and the characteristics of the formula, the characteristics of the equipment and the degree of wear, and the pressure of the upper top bolt. NR and formula with high glue content, k should be appropriately increased; For synthetic glue and formula with low glue content, k should be appropriately reduced; For old equipment with large wear degree, k should be increased; New equipment should be smaller; K of meshing rotor internal mixer should be smaller than that of shear rotor internal mixer; When the pressure on the top bolt increases, K should also increase accordingly. In addition, the K of the reverse mixing method must be as large as possible. When mixing in the mixer, the rubber must be subjected to a certain pressure from the top plug. It is generally believed that the upper top bolt pressure is 0.6-0.8MPa. When the rotor speed is constant, the effect of further increasing the pressure is not great. When the mixing capacity is insufficient, the upper top plug pressure cannot be fully exerted. Increasing the pressure of the upper top plug can reduce the non-filling space in the closed chamber and increase the filling degree by about 10%. With the increase of capacity and speed, the pressure of the upper top plug must be increased.