Study on the Effect of the Rheological Properties of Melt on the Die Cross-Section Shape for the Plastic Tube Extrusion Forming

摘要

The die optimization design is an effective way of overcoming the extrusion problems of plastic tube. Due to the obvious influence of the rheological properties of melt on the extrusion shape of the plastic tube, the reasonable cross-section shape of the die is one of most important factors in the die design. In this study, the effects of rheological properties of polymer melt on the cross-section shape of plastic tube were investigated. Numerical results indicate that the inner radius and the outer radius of the die's cross-section shape increase with the increasing of the viscosity, and the parameter of ε and ξ, but decrease with the increasing of the relaxation time. For the gap thickness of the die, the gas thickness increases with the viscosity, and the parameter of ε and ξ, but decreases with the increasing of the melt's viscosity.