HS test (Heat Soak Test)

HS test is applied in order to avoid the sudden thermal crack risk after glass tempering. Tempered glass can suddenly break because of expansion of nickel sulphide insertions being in glass. The glass breakage can occur even after several years of building exploitation.

Due to the time and temperature the insertions of nickel sulphide get into a phase interchange. If it is next to the centre of glass stress, the expansion of such insertions can generate enough stress causing spontaneous breakage. The insertions expand faster than glass and influent directly the inside breakage of glass.

Max. product dimensions: 2400 x 4800 mm.

During the HS test of tempered glass it is placed into the oven at the temperature of 290°C (±10°C). In order to set up the duration of exposure, an observant control of temperature is needed. The exposure at the highest temperature is an important factor during the HS test. After the HS test the risk of spontaneous glass breakage is reduced up to minimum.