HST hardening and hardening

HST Tempering and hardening

The tempering process is carried out for applications where certain levels of safety are required.

By increasing its surface tensions, glass allows to increase its mechanical resistance with which it will be able to face significant physical and thermal stress. The procedure consists in cooling the glass very quickly with air through the use of blowers. In a very short time the temperature is reduced from about 650 ° C to about 250 ° C thanks to which the surface tension is irreversibly modified. The breaking of a tempered glass occurs in small fragments, for this reason it is considered a safety glass. The hardening process is the same as that of the tempered glass but with a milder cooling, this generates artifacts with lower surface tensions than a tempered glass. Hardened glass maintains a higher strength than annealed glass and breaking occurs in coarse pieces, for this reason it is not considered a safety glass. The horizontal furnace is equipped with a pre-heated air “convection” system which allows to process all types of coatings on the market, including the latest generation coatings with very low emissivity coefficients. The HST process allows a tempered glass to reduce the risk of spontaneous breakage due to nickel sulphide. The cycle is calibrated according to the EN 14179 standard.
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