Modelling of heat transfer at glass/mould interface in press and blow forming processes

Numerical models may play an important role in the optimization of the quality of hollow-ware glass articles in glass industry. Due to the complexity of the phenomena involved a coupling between thermal and mechanical aspects is crucial. One of the key aspects required is a deep knowledge of the heat transfer at the glass/mould interface, a factor that may influence dramatically the final product. In this work an interface element developed to deal with heat transfer between glass and moulds in glass forming processes was introduced in a commercial code as a user element. The initial purpose was to make it possible to consider the dependence of the interface heat transfer resistance on process parameters like glass temperature and viscosity, mould temperature and contact pressure. In addition its implementation also proved to be an efficient tool to eliminate some perturbations introduced by the penalised form adopted in the commercial code to deal with non-matching meshes. A press and blow forming simulation of a Champagne flute was performed to assess the element performance on a real case study.