Method for preparing granular rubber by adopting three screw rods to continuously extrude devulcanized rubber powder

Abstract

The invention discloses a method for preparing granular rubber by adopting three screw rods to continuously extrude devulcanized rubber powder, and belongs to the field of waste rubber cyclic regeneration. Devulcanized rubber powder which is preliminarily and thoroughly cooled is added into a three-screw-rod extruder through a metering feeding device, high shearing, stretching and compression effects are applied on the devulcanized rubber powder on the lower temperature condition by means of the strong material conveying capability, the shearing and mixing capability and the high productivity ratio of the three-screw-rod extruder, a cross-linked network in the devulcanized rubber powder is damaged further, the Mooney viscosity of the devulcanized rubber powder is lowered on the premise of not lowering the mechanical property, a granular rubber product is obtained, and a traditional refiner is replaced. Operation is continuously completed by the adoption of the three-screw-rod extruder on the closed, low temperature and high shearing conditions. The devulcanized rubber powder Mooney viscosity lowering effect which is originally achieved by the traditional refiner is achieved, the production process is environmentally friendly and continuous and saves energy, the stability of the mechanical property and the Mooney viscosity of the obtained granular rubber product is better than that of a product obtained by the traditional refiner.

Description

Technical field: [0001] The invention relates to a new method for reducing the Mooney viscosity of desulfurized rubber powder, in particular to a method for preparing granular rubber by continuously extruding desulfurized rubber powder with three screws, and belongs to the field of waste rubber recycling. Background technique: [0002] With the development of my country's rubber industry, the demand for rubber resources is increasing, and a large amount of imports are required every year. In 2013, the self-sufficiency rate of natural rubber in my country was less than 25%, and the self-sufficiency rate of synthetic rubber was less than 60%. At the same time, waste But rubber is piling up more and more. In 2013, my country produced nearly 300 million waste tires with a weight of about 10.8 million tons. [0003] Scrap tires are industrial hazardous solid waste, insoluble or insoluble polymer materials, which will not disappear naturally for hundreds of years, and pollute soil ...

AI Technical Summary

Problems solved by technology

However, in the open high-speed shearing process of the refiner, it will bring a lot of smoke pollution, which can be said to be the most important source of air pollution in the whole process of desulfurization and regeneration of waste tires

Secondly, each equipment in the traditional refiner preparation process needs to be equipped with an operator. Not only the smoke pollution will endanger the health of the workers, but also the open high-speed refining opportunities will bring great safety hazards to the operators, and work-related injuries occur frequently.

The desulfurized rubber powder is forcibly cut by multiple refining machines and finally rolled out. The temperature of the film will rise above 100°C. Since rubber is a poor conductor of heat, there is not only the risk of spontaneous combustion during storage, but also the door Rebound of Ni viscosity and decline of product mechanical properties

In addition, the traditional method of multiple refining machines still has the disadvantages of high equipment investment cost, high energy consumption and low output

[0004] In order to reduce the environmental pollution caused by the refining machine, large-scale enterprises will use environmentally friendly ventilation and exhaust equipment, and even put the refining unit in a closed room to forcibly suck away the flue gas generated by high-temperature refining and shearing, but this type of environmental protection The effect of long-term use of dust removal equipment is not ideal

In addition, since each refining machine needs to be equipped with a worker, traditional treatment measures cannot solve the air pollution faced by front-line operators

In order to reduce manual participation, Huang Hanxiong et al. (CN201420326527.9) disclosed an automated production line for reclaimed rubber mixing process, using 4 open mills and 2 refiners connected in series, although the number of workers was reduced, the production was improved to a certain extent Efficacy, but the cost of equipment investment has been greatly increased, and the problems of air pollution and potential safety hazards have not been solved

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