Finite Element Simulation Of Melt Flow On The Extrusion Die For Two-layer Treads

Multi-layer treads are.widely used in tyre industry. At present, Coextrusion is the best way to make Multi-layer treads, and the heart df a Multi-layer treads extrusion line is its extrusion "die: Now most Multi-layer treads extrusion lines in China are introduced from other countries, and the others i are self-made by mapping those imported lines.In the past, we could only apply 2-D FEM to the analysis of the melt flow in extrusion dies with simple geometry and to their design. In this paper, 3-D FEM was used to simulate the melt flow in extrusion dies, and we can handle extrusion heads with complex geometry. On one hand, by quantitative analysis, we can design two-layer extrusion dies with certainty, and develop new-type extrusion dies easily and quickly. On the other hand, though Computer Aided Design, blindness in the determination of the channel parameters can be overcome and we can manufactory the die with less material and low cost in reduce time.In study, we supposed that the melt temperature is invariable, and using the basic controlling equations and Power law equations, we deduced Three-Dimension Non-Newtonian model to describe melt flow, we got the model which were similar to the true extrusion process, with the help of ANSYS software we obtain the velocity and pressure field in a two-layer extrusion tread die and a visual expression of the fluid distribution in the flow channel. During the analysis the flow channel was divided into several parts to get the details about the fluid flow in each area. A conclusion was drawn after analyzing the influence of the die pressure on the flow distribution, that the higher pressure is good for the output and bad for the uniformity of the distribution, and discussed the effect of the size of the block in the flow channel zone, the uniformity of some flow channel was so poor that the block in the proper position of the die channel was necessary.Then a computer program was developed to create the flow channel model and divide the element automatically, this program is the base of the optimization about the extrusion die with better geometry and the improvepent for the design of the extrusion die.