Tempered and Heat Strengthened Glass
Tempered and heat-strengthened glass is obtained by heating ordinary glass to its softening point and then suddenly cooling down to form compression in the surface layer of the glass, thus the mechanical strength is increased by times.
- Features of tempered glass
Safety: when broken, tempered glass becomes small granules, which prevent substantial hurt
to human body.
High strength: the strength of tempered glass is 4 to 5 times that of annealed glass.
Thermal stability: tempered glass has excellent thermal stability, which can withstand up to
300¡ãC thermal shock.
Tempered glass is a kind of safety glass and is widely used in places which call for high mechanical strength and safety, such as glazed door, curtain wall, vertical window, partition wall, and partition screen close to heat source and subject to violent thermal shock.
- Features of heat-strengthened glass
Heat-strengthened glass differs from tempered glass in its surface compression; its mechanical strength is about 1.6-2 times that of annealed glass. Heat-strengthened glass has outstanding thermal stability, and its flatness is close to that of annealed glass and better than that of tempered glass.
- Specifications
- Dimensions(mm):
Maximum dimension: 3300 x 9500
Minimum dimension: 200 x 300
Thickness (mm):
Tempered glass : 3 - 19
Heat-strengthened glass : 4 -19
Heat Soak Test
Spontaneous breakage is an inherent nature of tempered glass due to volume change occurred during crystal form transformation of nickel sulfide inclusions and other defects present in the glass. Heat-soak test is an effective procedure for bringing about spontaneous breakage before exiting works, thus limiting the possibility of spontaneous breakage after installation. By placing tempered glass in heat-soak furnace, heating to a desired temperature, preserving for enough time and cooling down, the crystal form of nickel sulfide inclusions is stabilized and the internal stress is relaxed to a certain extent. During this process, tempered glass with large enough nickel sulfide inclusions and other defects will be broken by induced extra stresses. As a result, heat-soak treated tempered glass will have a much less likelihood of spontaneous breakage than normal tempered glass.
- Specifications
Maximum size(mm): 2400x6000
Minimum size(mm): 300 x300
Thickness(mm): 3-19mm |
