SIMULATION AND EXPERIMENT ON PET AND BOPP MIXTURE SEPARATION BASED ON EDEM–FLUENT

To improve the efficiency and quality of polyethylene terephthalate (PET) recycling, the air separation recovery of PET and biaxially oriented polypropylene (BOPP) materials in broken plastic beverage bottles was explored and analyzed in this study. A gas–solid two-phase flow model was established to simulate the movement of flaky mixtures with different textures in the wind field. Analysis results show that wind velocity at the air outlet (A), initial material falling speed (B), angle between wind velocity at the outlet (C) and the horizontal direction, and material feed rate (D) are the key parameters that affected the separation. On the basis of the simulation results, an orthogonal experiment with four factors and three levels was designed, and range analysis and ANOVA were performed on the test results, which present the result of the influencing degree of each factor on the separation rate as follows: A > B > C > D. The fitting analysis of 3D scattered-point surfaces, the interaction between A and B exerts the greatest influence on the separation rate in the six groups of interaction experiments. The best separation parameters are acquired for the experiment, and the mass percentage of recycled PET is 99.96%, which achieve recycling requirements. Keywords: EDEM–Fluent coupling; Air separation; Orthogonal experiment; PET/BOPP mixture