3D simulation and parametric analysis of polymer melt flowing through spiral mandrel die for pipe extrusion

With the increasing demands for large scale and high productivity, polymer pipes are recently produced using the advanced spiral mandrel dies. However, the fundamental research related to polymer melt flow mechanism in the spiral mandrel die for pipe extrusion is lagging behind. In the present study, the mathematical model for such a complex three-dimensional non-isothermal viscous flow of polymer melts obeying power law model was developed based on computational fluid dynamics theory. Finite volume element method was applied to predict the rheological behaviors of polymer melt flowing through the complex flow channel. The essential flow characteristics including velocity, pressure drop, wall shear stress, and temperature were investigated. The effects of both mandrel structure parameters and mass flow rate upon the flow patterns were further discussed. Some recommendations on spiral mandrel die design for pipe production were put forward.