聚氯乙烯搪塑粉塑化成型与温度的相关性

Correlation Between Plasticization Molding and Temperature of Polyvinyl Chloride Slush Powders

采用HAAKE流变仪和熔体流动速率测定仪,研究了在不同温度下2种聚氯乙烯搪塑粉MT1和MT2的塑化性能和熔体流动速率。结果发现,搪塑粉塑化时最大扭矩和塑化时间与温度呈明显的相关性,在180℃以下,温度越高,搪塑粉塑化扭矩越小,塑化时间越短;在相同温度下,MT2搪塑粉比MT1搪塑粉具有更高的塑化效率和更优异的熔融性能。通过偏光显微镜观察了2种搪塑粉在不同温度的熔融合并过程,展示了搪塑粉在熔融过程中的形貌演变特点,并定量计算了不同温度下2种搪塑粉熔融的相对铺展面积和速率。通过自制的搪塑机和模具制造了2种搪塑表皮,其搪塑成型性能与上述的实验结果能够很好地吻合。该研究有助于搪塑工艺和材料的优化设计。

HAAKE rheometer and melt flow rate tester were used to study the plasticizing performance and melt flow properties of two kinds of polyvinyl chloride （PVC） slush powders （named MT1, MT2）. The results show that the slush powders’ plasticizing torque and plasticizing time are associated with the processing temperature. Below 180 ℃, the higher the processing temperature is, the smaller the plasticizing torque is, and the shorter the plasticizing time is. MT2 powder displays higher plasticizing efficiency and more excellent fusion behavior than MT1 at the same temperature. The morphology evolution of powder melting and merger processes was observed by polarizing microscope, and the relative spreading area and the melting rate of the two kinds of slush powders at different temperature were calculated. Two kinds of slush molded skins were made by home-made slush molding machine and mold, the slush molding performances of which are well consistent with the above-mentioned experimental results. This study is helpful for the optimal design of slush molding processes and materials.