Process prototyping - Physical model of the glass pressing process

Abstract

A physical model of the glass pressing process has been developed based on the theory of dimensional analysis. The main objective of this approach was to set up an equivalent model process operating on a significantly lower temperature level than the original pressing process. Therefore a model glass had to be found that showed the same thermoviscous behavior as the glass used in the original production. It is proved mathematically that at least one type of nitrate glass matches these requirements. Initially, the process under examination had to be described dimensionlessly. Starting from this dimensionless base, scale equations could be derived according to the model laws of dimensional analysis. Besides, the dimensionless mathematical treatment of the thermoviscous material properties of glass revealed more common grounds among different types and compositions of glasses than expected. In the following paper the fundamental principles and boundary conditions related to the problem of physically modehng a real glass forming process are discussed.