Research On Composite Separation Technology And Equipment Of The Soft Package Plastics

Plastic packing industry strongly impelled the progress of the food, cosmetic, pharmaceutical industries and brought out great material civilization. While the emergence of a large number of plastic wastes posed serious challenges to people, it also gave us new opportunities. Therefore, it is urgent to separate and recycle soft package plastics.Firstly, the advantages and disadvantages of the current single wind-separation and vibration-separation were analyzed, aimed at the characteristics of soft package plastics, a new technology of wind-and-vibration multiple separations was put forward, the process flows of the multiple separations were verified, the mechanisms of the wind-separation system and the vibration system were selected, finally, the wind-separation of inclined airflow in combination with the crank rocker vibration-separation of the eccentric forms were determined as the best technical solutions to the separation of soft package plastics.With wind-separation principle and fluid mechanics knowledge, the motion laws of soft package plastics mainly the lightweight materials in the flow field as well as the main factors that influenced the motion of lightweight materials were analyzed. The simulation model was established to precede simulation optimizations, and then the optimum data of wind speed, inclination angle of wind and other parameters were verified.The motion model of lightweight materials on the vibration sieve was analyzed and researched, the movement theory of materials on the vibration sieve was verified, the corresponding displacement, velocity and acceleration equations of the materials were obtained, and then motion forms of materials were classified according to different movement conditions. The mathematical model for motion optimization design of various materials on the vibration sieve to separate effectively was established, the objective functions were built up, the appropriate design variables were selected, the reasonable constraint conditions were explored, and the objective optimization functions were established. The optimization model was solved with optimization toolbox in MATLAB; the optimum values of the direction angle of vibration and inclination angle of the sieve were obtained.The structural features of the multiple separation equipment of soft package plastics were studied, in combination with the selection of mechanism and the optimization values of key parameters, the other key parts of the equipment were selected and calculated. The regulation devices of the wind direction, the adjustment devices of the angle of the sieve, the shape of the sieve were designed reasonably, and the overall prototype was designed and developed.The physical model of the vibration system of the separation mechanism was established with virtual prototype technology in combination with ADMAS simulation software, after motion simulation analysis, displacement, velocity and acceleration curves of single materials on the sieve were obtained. On this basis, motions of multi-materials on the vibration sieve were simulated and analyzed, the corresponding curves of the variation of the displacement shift were obtained, the key factors that influenced the displacement shift were obtained, and these verified the correctness of theoretical analysis.This research is supported by the National Natural Science Foundation of China; it is a part of the items (Y2008F02).