HST checkmarker: Legal check marking for heat soaked toughened glass
In order to make spontaneous breakings less likely, toughened glass should undergo the Heat Soak Test (HST) process. This treatment is to detect nickel sulphide (NiS) inclusions inside the glass. At a temperature of about 290°C over a defined dwell time of 2 - 4 hours, an expansion of the NiS inclusions is caused what leads to a desired breakage of the pane. Thus, the HST process ensures only a minor residual risk for a spontaneous breakage of the pane after it is used for glazing.
In legal cases, the glass manufacturer as to proof that the glass was HST treated. HST checkmarker® is a patented, thermocromic and UV active ink what enables the unambiguous and forgery-proof verification of the successful Heat Soak Test at toughened safety glass.
Soon available: The HST checkmarker stamp with individual layout.