The production or introduction of new speciality glasses requires a long and expensive period of development. Timeintensive melting processes needed to analyze properties and melting behavior of the new glasses still further increase the costs. It is a great effort to technologically enable accurately reproducible casting processes. Even a delay of only a few seconds during the casting can significantly change some of the properties.
The automatic approach
The automation of the melting process for a systematic development of glass systems reduces costs significantly and improves the reproducibility.
The automatically produced samples can be characterized quickly and efficiently in our laboratories; some properties can be determined in situ during the melting process.
The screening apparatus
The worldwide unique screening apparatus developed at Fraunhofer ISC consists of a weighing unit for 10 components and an electrically heated furnace (up to 1700 °C) and 5 independently working furnaces (up to 1750 °C). A robot performs the powder mixing and then transfers the homogeneous powder into the furnace chamber. The glass is melted and homogenized in a platinum 100 ml crucible. Then the liquid glass is poured out into a stainless steel crucible. The glass is cooled down slowly in a separate furnace to relieve stress. This allows for a production of 16 different samples of glass with a defined batch composition of high optical quality within 20 hours.
The following parameters are variable:
- Automatic raw material dosing of up to 10 components
- Adjustable melting program for individual samples
- Selection of themodynamic models for possible glass systems