Thermally Processed Glass: Correlation Between Surface Compression, Mechanical and Fragmentation Test

The paper correlates the data recorded in Stazione Sperimentale del Vetro, during qualification tests. The aim of the research is to define a correlation between the following parameters in toughened and strengthened glass:

  1. bending strength tested according EN 1288-3;
  2. fragmentation tested according EN 12150;
  3. surface compression stress tested according ASTM 1279.

Also thermally strengthened glass data were considered, whereas it is not possible in term of fragmentation due to the different crack path (“island” fragments instead of small fragments).

The research is the development of the previous ones carried out at Stazione Sperimentale Vetro (2005-2011), focused mainly on the correlation between surface compression stress and bending strength, introducing the fragmentation parameter.

In the present research those experimental data are increased (up to 2016) and the correlation is extended also to enamelled glass.

The correlation between surface compression stress and mechanical strength and fragmentation is relevant for the manufacturer, who may use surface pre-stress measurement as a means of product control.