Effect of die design on the analysis of wire coating

A general-purpose finite element program has been used to analyze the flow of LDPE and plasticized PVC inside wire-coating dies under typical operating conditions. The analysis is fully two-dimensional and nonisothermal. It is shown that die design has a strong effect on the flow and temperature patterns, especially for the more sensitive PVC compound. The analysis can be used as a guide for optimum operating conditions and for better die design that allows for faster wire speeds without occurence of melt fracture and rough coating surface.