Thermo-mechanical stresses in cast steel dies during glass pressing process

Cast steel dies used in glass pressing process present an important dispersion in their lifetime in spite of apparently similar pressing parameters. In order to know if undetectable variations of any process parameter could produce such lifetime dispersal, a finite element simulation of glass pressing process is proposed. In this paper, glass is supposed to be a Newtonian fluid, the mould is considered as a thermo-elastic material, thermal transfer between glass and mould depends only on time and radiative heat transfer in glass is not taken into account. The validation of the results of this simulation is performed by comparison of the calculated pressing force and of the experimental one. Although the data introduced in the simulation are taken from the literature on the subject, the order of magnitude of the calculated pressing force is similar to the industrial one.