Device and method for continuously preparing small-particle reclaimed rubber with low Mooney rebound

Abstract

The invention discloses a device and method for continuously preparing small-particle reclaimed rubber with low Mooney rebound. The device comprises a base, wherein a motor is arranged on one side of the top of the base, a mounting base is arranged on the other side of the top of the base, a reduction gearbox and a double-screw extrusion mechanism are arranged at the output end of the motor, the input end of the reduction gearbox is connected with the double-screw extrusion mechanism, and a first extrusion conveying section, a compression refining section, a shearing refining section and a steady flow cooling conveying section are arranged in the double-screw extrusion mechanism. According to the invention, continuous automation of reclaimed rubber refining production is realized, the whole operation process is realized in a closed environment, and environmental protection and labor saving are realized. Supercritical carbon dioxide fluid is added in the compression refining section, so that the Mooney viscosity of desulfurized rubber powder is greatly reduced, and a damaged cross-linked network is homogenized; and in addition, the torque of an extruder is reduced, and the equipment manufacturing difficulty and the use energy consumption are greatly reduced.

Description

technical field [0001] The invention relates to the technical field of reclaimed rubber, in particular to a device and method for continuously preparing small particle reclaimed rubber with low Mooney rebound. Background technique [0002] Reclaimed rubber has always been the main way of recycling waste rubber in my country. On the one hand, it can reduce the dependence on external rubber resources, and on the other hand, it can effectively solve the problem of "black pollution" caused by waste tires. The output is about 300 million pieces, and the weight is more than 10 million tons. The preparation process of reclaimed rubber is divided into the desulfurization stage and the refining stage of the rubber powder. The desulfurization stage is the process of selectively breaking the S-S bond or C-S bond of the rubber powder. Desulfurized rubber powder has a certain use value, but its processing fluidity is too poor, and its mechanical properties, especially the elongation at bre...

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Problems solved by technology

[0002] Reclaimed rubber has always been the main way of recycling waste rubber in my country. On the one hand, it can reduce the dependence on external rubber resources, and on the other hand, it can effectively solve the problem of "black pollution" caused by waste tires. The output is about 300 million pieces, and the weight is more than 10 million tons. The preparation process of reclaimed rubber is divided into the desulfurization stage and the refining stage of the rubber powder. The desulfurization stage is the process of selectively breaking the S-S bond or C-S bond of the rubber powder. Desulfurized rubber powder has a certain use value, but its processing fluidity is too poor, and its mechanical properties, especially the elongation at break, are not good. Therefore, it is necessary to further refine the desulfurized rubber powder by strong shearing and reduce the Mooney to ensure The reclaimed rubber has both good mechanical properties and processing fluidity. It can be seen that the refining stage is of great significance to the preparation of reclaimed rubber;

[0003] The refining extruder needs strong shearing to complete the process of refining the desulfurized rubber powder and reducing the Mooney process. The prepared reclaimed rubber has good mechanical properties and processing fluidity, but there are many problems in the refining extrusion process: such as reclaimed rubber particles The extrusion temperature is too high, about 100~120°C, the particle size is too large, it is not easy to dissipate heat, and the particles stick together and form agglomerates; it is difficult to prepare particle reclaimed rubber with a Mooney viscosity lower than 60, and the reclaimed rubber has the unique viscoelastic response of rubber materials , and the higher the temperature, the more viscous the response will be. Therefore, the reclaimed rubber particles extruded at too high a temperature will easily stick to the surface of the subsequent cooling and conveying equipment. Both will affect the cooling, transportation and packaging of granular reclaimed rubber, and even block related equipment. Secondly, reclaimed rubber is a poor conductor of heat. During the feeding of desulfurized rubber powder, the excessive particle size will further affect its heat dissipation effect and it is easy to adhere Together, it will cause the feed inlet to be blocked, and the subsequent heat treatment will take a long time, which will exacerbate the problems of particle regeneration, adhesion and agglomeration, and when the release agent is added, the powder of the release agent will easily adhere to the inner wall of the feed inlet. Increase the inconvenience of follow-up cleaning work and affect the normal delivery function of the release agent. When the heat source inside the device overflows, it is not easy to remove it, and the directly discharged heat source will mix the working environment and affect the air quality of the surrounding environment. In addition, A major difficulty in the reclaimed rubber industry is that the Mooney viscosity of reclaimed rubber is not a fixed value, and it will increase with the prolongation of storage time, and the Mooney viscosity is an important indicator to measure the fluidity of reclaimed rubber. Mooney The greater the viscosity, the worse its fluidity. The biggest factor affecting the Mooney viscosity rebound of reclaimed rubber is the temperature during storage. The higher the temperature, the faster the Mooney rebound speed. Therefore, excessive extrusion temperature, excessive extrusion Particles and adhesions will greatly affect the heat dissipation of the reclaimed rubber particles, which will greatly shorten the effective storage time

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