Because of the large surface area of silica, it tends to accumulate twice. In addition, it is easy to absorb water in the air, which makes it easy to produce strong hydrogen bond association between hydroxyl groups, which further improves the cohesion between particles. Mixing and dispersion are much more difficult than carbon black, and when a large amount is mixed, it is easy to form gel, which hardens the rubber and generates heat during mixing. In order to obtain a good dispersion, it is required to maintain as high a shear force as possible during the initial mixing, so that these aggregate particles of silica can be destroyed as much as possible without causing excessive mechanical degradation of the rubber molecular chain. . For this reason, white carbon black should be added in small quantities in batches to reduce heat generation. Properly increasing the mixing temperature will help remove part of the silica surface adsorbed water, reduce the cohesive force between particles, and help the dispersion of the silica in the rubber compound.