The size of the compound for each compounding must be reasonably determined according to the equipment specifications and the formulation characteristics of the compound. If the capacity is too large, the amount of accumulated glue above the roll is too large to enter the roll gap, and the dispersion mixing effect is lowered. And the poor heat dissipation will cause the rubber to heat up, causing scorch and affecting the quality of the rubber compound. It can also cause equipment overload and increase labor intensity. Too small a capacity will reduce production efficiency. For the compound with low gel content and high calorific value, the capacity should be appropriately reduced; the natural rubber formula should have a lower calorific value and the capacity should be increased appropriately. The rubber compound mixed with the master rubber should also be used. Increase the capacity as appropriate.

A reasonable capacity is to maintain an appropriate amount of build-up glue between the two rolls at a lay length of 4 to 8 mm. The roller distance is reduced, the mechanical shearing effect of the rubber material passing through the roller distance is increased, the mixing speed is accelerated, and the heating temperature of the rubber compound is also accelerated, the amount of the glue is increased, and the rubber material is difficult to dissipate heat. Dispersive blending. As the compounding agent is continuously added, the volume of the compound increases and the roll distance should be gradually adjusted to increase the amount of accumulated glue.

The rotation speed and speed ratio of the roller increase the rotation speed and speed ratio of the roller to improve the mechanical shear dispersion effect and the kneading speed. The heating temperature of the rubber compound is also accelerated, which is not conducive to the dispersion of the compounding agent, so the temperature must be strictly controlled. To prevent scorch; too low speed and speed ratio will reduce mixing efficiency. Therefore, the speed ratio during mixing is appropriately reduced compared to mastication, and the suitable range is 1:1.2.

Mixing temperature and time Increasing the mixing temperature is beneficial to the plastic flow of the rubber compound and its wetting of the surface of the compounding agent, which accelerates the powdering process but reduces the dispersion effect. Rolling temperature over the rubber compound is prone to roll-off and scorch phenomenon, affecting the mixing operation and mixing quality; the roll temperature is lowered, the viscosity of the rubber is increased, which is beneficial to improve the mechanical shearing and dispersing mixing effect, but if it is not conducive to Eat powder mix. If the temperature is too high or too low, the mixing time will be extended. Therefore, the mixing temperature should be adjusted according to the characteristics of the rubber compound, so that the temperature of the roll is maintained within the best temperature range of the rubber roll. The temperature of the front and rear cylinders should be kept at a temperature difference of 5 to 10 °C to facilitate operation. For example, the natural rubber is easy to pack hot rollers, the front roller temperature should be higher than the rear roller, and the synthetic rubber is the opposite.

The mixing time of the open mill depends on the formula and properties of the rubber compound, the mixing operation method and the process conditions. The insufficient mixing time will reduce the uniformity of the rubber compound mixing; the mixing time is too long, and the rubber compound is prone to scorch and over-refining. , reduce the quality of the rubber compound and production efficiency. The appropriate mixing time is determined by experimentation. The mixing time is shortened as much as possible to ensure the quality of the rubber compound, and the production efficiency is improved.