Study On Development Of Polyvinyl Chloride Injection Screw With High Performance And Novelty And Its Properties

Recently, there is a steady increase in the demand of polyvinyl chloride (PVC) injection products. While in the PVC injection molding, PVC products are molded by conventional injection screw, which has poor plastication and restricts the improvement of molding process in efficiency. In the same time, the poor products cannot meet the expectations of high performance. Therefore, it is significant to study on polyvinyl chloride injection screw with high performance and novelty.In this study, on one hand, we focused on filling and blending of PVC material. The content included three aspects, RIF toughing PVC (as well as treatment of filler and content of filler), elastmor toughening PVC and selecting compatibilizer. It is indicated that the perfect dispersive capacity of CaCO3 was gotten after CaCO3 was dealt with stearic acid. After filled with 20 phr CaCO3, the impact strenth of PVC compound materials still increased by 40%. PVC compound materials would be toughened by SBS, especially after added CPE. When the content of plasticizer reached 40 phr, the soft PVC materials had good performance.On the other hand, we designed 8 combination injection screws,and did experiment by the novelty injection screw with three formulas. There were three kinds of properties tested, including effect of distributive blending, effect of dispersive bending and mechanical properties. It is indicated that perfect mechanical properties and excellent microscopic morphology were gotten after PVC compound materials molded by pineapple injection screw, and the clearance of Maddock injection screw played an important role in PVC plasticizing efficiency.In addition, the models in homogenizing zone were established to analysis the movement of melt PVC in common screw, pineapple screw and Maddock screw. Fundamental reasons that influenced the plastication were carried out.