旋转机头内往复剪切应力场的作用

The Effects of Reciprocating Shear Stress Field in Rotating Parison Die

本文从理论角度探讨了挤出环状型坯的机头旋转(或往复旋转)改善制品的质量及性能机理。在一定的简化条件下,建立了描述熔体在旋转环隙内作非等温流动的数学模型。采用无量纲分析及有限差分的方法,定量地分析了在主要流动为轴向层流的流场中附加周向剪切力场在改善聚合物熔体流变性能、降低挤出功耗方面的作用,为旋转机头的设计及工艺参数的优选奠定了理论基础。

In this paper,the mechanisms of improving articles quality through therotation(or reciprocating rotgation)of annulus die for parison extrusion were dicu-ssed.Under certain simplified conditions,a mathematical model for descriptionof non—isothermal flow of polymer melts in rotating die annulus was establi-shed.With dimensionless analysis and finite element method,the effectsofadditional circumferential shear stress field in flow fields,where the axial poisulleflow is in dominance,on improving the rheological properties of polymer meltsand reducing the extrusion power consumptions were analyzed,and a theoreticalbasis for optimization of design and operation parameters for rotating dies alsowas set up.