Nickel Sulphide: New Results To Optimise The Heat Soak Test For Thermally Toughened Building Glasses

By kinetic investigations on synthetic nickel sulphides and by statistical analysis of the breakage of heat soak test ovens, it is shown that the problem of NiS can be solved. If the test is done carefully and correctly holding time need not be longer than 2 to 3 hours to fulfil the implicit requirements of German Standard DIN 18516. On the other hand, literature shows that it should be possible to further shorten this holding time if it were possible to heat the glass up faster and more homogeneously.