Study On The Separation Technology Of Different Melting Plastics And The Optimization About The Structure Of The Barrier Screw

How to separate different varieties of mixed waste plastics effectively and rapidly is a serious problem for plastics recycling. Based on the analysis and comparison on the existing methods of recycle and separation of waste plastics, the separation process of different varieties of plastics for barrier screw was studied in this paper. The separation principle of separating plastic extruder was researched and analyzed with the method of screw ejection. The plastic separation model was built, and the mathematical expression and design method for the barrier screw pitch was proposed. The effect of screw structure on the separation efficiency and separation purity was studied experimentally and theoretically. On this basis, choosing the separation efficiency and separation purity as the target, the barrier screw configuration and the operating parameters were optimized, and an efficient separation screw configuration was proposed.The results showed, the barrier screw pitch depends on the different proportions of mixed plastic, the greater the ratio is. the greater the pitch of the barrier screw should be; increasing the screw compression ratio and length diameter ratio can effectively improve the separation efficiency and purity. This paper presents a new and efficient separation screw which separation purity can reach more than98%and the separation efficiency is over80%. It has potential applications in separating different melting mixed plastics.