Yao Glass supply heated soaked thermally toughened safety glass according to EN14179-1:2016.

Heat soaked thermally toughened safety glass has a safer breakage behaviour when compared with annealed glass.

Glass within which a permanet surface ompressive stress, addtionally to the basic mechanical strength, has been induced by a controlled heating and cooling proces in order to give it greatly increased resistance to mechanical and thermal stress and prescribled fragmentation characteristics and which has a known level of reisdual risk of spontaneous breakage due to the presence of critical nickel sulphide(NiS) inclusions. It's no more than one breakage per 400t for heat soaked thermally toughened safety glass.

Heat soak process cycle consists of a heating phase, a holding phase and a cooling phase.

The heating phase commence with all the glasses at ambient temperature and concludes when the surface temperature of the glass glass reaches 250°c . The maximum heating rate is 3°c per minute. The glass surface temperature shall not be allowed to exceed 290°c. 

The holding phase commences when surface temperature of all the glass has reached a temperature of 250°c. The miniumu duration of the holding phase is 2 hours. 

The cooling phase commences when the last glass to reach 250°c has completed its holding phase, i.e. been held for minimum 2 hours at 260°c+-10°c. The cooling phase can be concluded when the air temperature in the oven reaches 70°c.