Numerical modelling of glass forming processes

Abstract

Application of the finite element method to the simulation of glass forming processes is described. The forming process results in a coupled thermal/mechanical problem with interaction between the heat transfer analysis of the temperature distribution in the glass and the viscous flow formulation describing the deformation of molten glass being a dominant factor. Particular attention must be given to derivation of the appropriate non-linear thermal boundary conditions and also to monitoring of the mechanical contact between the glass and mold. The technique described provides both the glass and temperature distribution at each instant of the forming process and thus can provide invaluable information for mold and plunger design, optimum operation times, etc. Numerical examples are provided for both wide neck and narrow neck press and blow forming processes and the results obtained compare well with commercial observations.