Numerical simulation on the influence of geometric size on the swell for traditional and gas-assisted extrusion of plastic micro-pipe

Abstract

In this paper, to study the influence of geometric size on the swell of extrusion forming of plastic micro-pipe, we performed the numerical simulation based on the finite element software Polyflow. The geometric models of plastic micro-pipes with different inner diameters but same wall thickness were established. Under the same boundary conditions and material parameters, the extrusion forming and swell ratios of plastic micro-pipes with different sizes were obtained. At the same time, the numerical results of traditional extrusion forming were compared with that of the gas-assisted extrusion forming. Numerical results show that the swell ratio of outer diameter and wall thickness increase with the decreasing of the geometric size for the traditional extrusion, but the extrudate swell of plastic micro-pipe is well eliminated by using the gas-assisted method.