As the name suggests, the mixer is used for mixing materials (such as rubber, plastic, etc.). The mixer can be divided into closed type (internal mixer) and open type (open mixer).
　　 Closed mixing is divided into three stages, namely wetting, dispersing and smelting, and mixing stones with internal mixers under high temperature and pressure. The operation method is generally divided into one-stage mixing method and two-stage mixing method.
　　One-stage mixing method refers to the method of mixing through a mixer at one time, and then compressing tablets to obtain a rubber compound. It is suitable for all natural rubber or compounds with no more than 50% of synthetic rubber. In one stage of mixing operation, batches and gradual addition are often used. In order to prevent the compound from rising sharply, slow banburying is generally used. Two-speed internal mixer can also be used, and the temperature when sulfur is added must be lower than 100°C. The feeding sequence is raw rubber-small material-reinforcing agent-filler-oil softener-discharge-cooling-adding sulfur and super accelerator.
The mixing process of the open kneader is divided into three stages, namely, wrapping roller (softening stage when raw rubber is added), eating powder (mixing stage when powder is added) and mixing (after eating powder, the raw rubber and compounding agent are all reached Evenly dispersed stage).
　　 The temperature of open plastic mixing is generally below 80℃, which is a low-temperature mechanical mixing method. The debinding temperature of closed mixing is above 120℃, even as high as 160-180℃, which belongs to high-temperature mechanical mixing.