| China is the largest consumer and importer of rubber in the world. But a large number of discarded tires cause serious environmental problems and resource wasting, and the production of rubber powder by crushing the tire is one of the means of green recycling. High pressure water jet can crush the tire at room temperature, and has broad application prospects in the field of tire recycling. The crushing efficiency directly affects the recovery rate of the tire, and the performance of the rubber powder directly determines its value, both of which are affected by the water jet parameters.Characterization method of crushing efficiency was established. Single factor experiment was applied to simulate the regulation of crushing efficiency regarding the water jet parameters’ changing and orthogonal experiment was used to estimate the effects degree of different parameters. The performance of rubber powder was characterized by particle size, surface oxygen group, infiltration and desulfurization, and the relationship between the performance and parameters of water jet was analyzed. The interaction between rubber powder and the matrix material and the relationship between the reusing performance and water jet parameters was studied by reusing experiment. The response surface model of relation between the crushing efficiency and water jet parameters was established, and the interaction between different parameters of water jet was analyzed.Results show that the crushing efficiency is mainly affected by the pump pressure, and improving the pump pressure and the nozzle moving speed at the same time can improve the crushing efficiency significantly; effect of water jet on the performance of rubber powder is mainly due to output kinetic energy, cluster and dissipation, action time of water jet, high temperature and high pressure caused by impact and cavitation effect and embrittlement effect of tread compound.From the conclusions above, the scope of water jet parameters was determined by the reusing performance of rubber powder. Water jet parameters was optimized to ensure the performance of rubber powder under the premise of improving the crushing efficiency, in order to realize the high efficiency and high value recycling of waste tire. |
