Rubber final mixing process for internal mixer

Abstract

The invention belongs to the technical field of rubber mixing, and relates to a rubber final mixing process for an internal mixer. The rubber final mixing process comprises the following specific steps that (1) the temperature of an internal mixing chamber is increased to 120 DEG C; (2) a vulcanizing agent is added into the internal mixing chamber, and a top peg is dropped down for heat preservation; (3) chopped mixed rubber blocks are added into the internal mixing chamber; and (4) an accelerant is immediately added after the mixed rubber blocks are added, the top peg is dropped down for mixing, the temperature of the internal mixing chamber is set to be higher, the Mooney viscosity of rubber materials is quickly reduced under the action of liquid sulfur, the shearing action of a rotor is reduced, the temperature of the whole internal mixing chamber is reduced by rubber compound with lower temperature, and the temperature is kept within a proper range. The vulcanizing agent is firstly added for melting, then the rubber compound is added, the rubber compound is uniformly mixed with the vulcanizing agent in the heating plastication process, the accelerant is immediately added for mixing after rubber adding, the vulcanizing agent and the accelerant are separately added, and the accelerant is added at the last, so that the scorching phenomenon of the rubber materials can be avoided to the greatest extent.

Description

Technical field: [0001] The invention belongs to the technical field of rubber mixing, and relates to a rubber final mixing process for an internal mixer, which can improve production efficiency. Background technique: [0002] Final mixing is an indispensable and important step in the rubber processing process: adding vulcanizing agent and accelerator to the rubber compound after mixing in the internal mixer or open mixer, and mixing it evenly, it is unloaded. The vulcanizing agent is mainly sulfur. The melting point of industrial sulfur is 112.8 °C and the flash point is 207 °C. The ordinary rubber processing will not reach the flash point of sulfur. Controlling static electricity and open flames during processing can ensure processing safety. The addition of sulfur can reduce the Mooney viscosity of the rubber compound, and a higher mixing temperature can also reduce the Mooney viscosity of the rubber compound and improve the processability. [0003] The traditional final...

AI Technical Summary

Problems solved by technology

Most final mixing internal mixers use low speed to prevent rapid temperature rise, but the shearing and kneading action of the rotor of the internal mixer will still produce a large temperature rise, and will make the masterbatched rubber produce more Shearing breaks the chain, affecting the performance of the compound

At the same time, the faster temperature rise will also lead to short mixing time of rubber materials, uneven mixing time between different batches, large differences in final rubber vulcanization curves, low production efficiency, and difficulty in meeting production needs

[0004] In addition, when the rubber industry conducts final refining with internal mixers, it will try to reduce the final refining temperature to prevent scorching. However, during the final refining process , the lower temperature of the mixed rubber will heat up rapidly under the shearing and kneading action of the rotor; when the interval between the two stages of mixing is long, the mixed rubber will become hard, and if the internal mixer is directly added to the final mixing Hard rubber compound will have a greater impact on the internal mixer, resulting in a large torque mutation, loss of equipment, and increased energy consumption

If the mixed rubber is heated up, pressed into tablets or crushed and added to the internal mixer, the steps are complicated and the energy consumption is high

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