Tempered Glass

Product Description

Tempered glass is to intenaerate the ordinary annealed glass and then cool it evenly and sharply in the furnace, which results in the compression stress on the surface and tension stress inside of the glass to increase the strength and heat stability.

The characteristics of tempered glass

1.  High Strength: The strength to withstand bending is 2 -4 times higher than that of the normal annealed glass, while its impact strength is 4 - 7 times higher.
2.  High Wind pressure resistant ability: The ability of tempered glass to resist wind pressure is 2 times higher than that of normal annealed glass.
3.  Stability to heat: Its ability to resist heat impact is 3 times of that of ordinary normal annealed glass.
4.  Security: The Tempered glass is not easy to break when impacted because of its high strength. Even if destroyed by heavy force, the shatters will be obtuse and have few danger to human body.

The inherent limitations of tempered glass
1.  Self cracking
The finished tempered glass happens to crack down without any outside impact, that is what we called "self-cracking". The main reason for glass self cracking is the tiny impurity of nickel sulfide which was brought into the glass from the raw material. The flaws of base glass sheet, a unsuitable pretreatment or an uneven cooling process during toughening are also can result to self-cracking. The average happening probability of self-cracking is 3‰.
2.  Stress Flecks
To look the tempered glass under a special natural light (or polarized light), there are obvious chiaroscuro spots and stripes which are named stress flecks, these flecks impact the appearance of tempered glass greatly. Stress flecks have direct relations with the tempering processing technics, it is the visible representation of the uneven distribution of stress in the tempered glass.
3.  Light aberrated
Under a certain lighting, there are obvious distortion for the objects reflected on the tempered glass, which is because the glass distortion during toughening.

In order to minimized the above mentioned liminations, Nanjing Yaohua takes several measures as following:
1.  Select high grade float glass sheets and take strict care of pretreatment quality.
2.  Applied purely flat speckless furnace and compulsory convective furnace to make the glass get sound heating and cooling during the toughening, and control the surface stress in order to stop the stress flecks and light aberration from happening.
3.  Introduced advanced heat soak oven, in which the tempered glass is heated second time quickly to make the potential self cracking happen in the oven instead of the installation later. After the heat soak, the happening probability of self-cracking can be reduced to 1/1000000.

Spcifications

Thickness: 3 - 19 mm
Min. Size: 300 x 300 mm
Max. Size: 2850 x 8000 mm