Effects of interfaces heat fluxes on the rheological and flow behaviours of melt in the gas-assisted extrusion of plastic micro-tube

Abstract

Abstract In this study, the effects of interfaces heat fluxes on the rheological and flow behaviors of melt in the gas-assisted extrusion of plastic micro-tube were numerically investigated. In the numerical studies, the heat transfer effect at the interfaces between the annual melt and two layers of assisted gases were considered. Under four different heat transfer coefficients, the radial and axial velocities, pressure, temperature, and viscosity distributions along the axial direction of die were obtained. Numerical results show that, in the gas-assisted extrusion of plastic micro-tube, with the increase of interfaces heat fluxes (heat transfer coefficient), the radial velocity, axial velocity, and temperature distributions of melt gradually increases, but the pressure, viscosity of melt gradually decreases. At the same time, the larger interfaces heat fluxes will result in the better flowability of melt in the gas-assisted extrusion of plastic micro-tube.