三螺杆挤出机螺杆元件混合特性的数值研究

采用聚合物流体分析软件Polyflow对倒三角形三螺杆挤出机的6种螺杆元件的流道模型进行了三维等温数值模拟。使用Fieldview软件对结果进行统计处理，并采用不同的评价指标来表征混合性能，进而比较螺杆元件之间的混合特性。结果表明，捏合块的剪切和拉伸作用均强于螺纹元件；中性捏合块和左旋元件的回流效果好于其他元件；SME元件剪切弱于螺纹元件，但其拉伸作用和回流效果强于螺纹元件。因此，可根据物料对剪切的敏感性来合理地选择螺杆元件，以获得所期望的产品性能。

Numerical Study on Mixing Characteristics of Screw Elements in Three-screw Extruders

Three-dimensional isothermal flows of different screw elements in a three-screw extruder were simulated using a polymer analysis package Polyflow.By statistical treatment of numerical results using Fieldview software,the mixing performances of screw elements were characterized and compared in terms of different evaluation methods.It was found that the kneading blocks had stronger shearing and stretching actions than other elements,and neutral kneading blocks and left-handed elements had better effect of backflow.Compared with screw thread elements,SME elements had weaker shearing capacity,but higher stretching and backflow capacity.The screw elements could reasonably be selected based on the shear sensitivity of the materials in order to improve the quality of the products.