CALCULATION OF TEMPERATURE DISTRIBUTIONS DURING THE SOLIDIFICATION STAGE IN CERAMIC INJECTION-MOLDING

A finite difference procedure for calculating unsteady-state temperatures in a molded ceramic-polymer suspension during solidification is described. The method incorporates temperature-dependent thermal diffusivity and enthalpy of fusion of the polymer. An experimental method is used to assess the surface heat transfer coefficient h at the mold wall. It is found that at low injection pressures h varies with time as the molded body shrinks from the wall, but at high injection pressures h can be treated as constant throughout the solidification stage. Using an analytical method, graphical charts are produced for dimensionless temperature as a function of dimensionless time for values of Biot's modulus in the region relevant to ceramic injection molding.