Safety glass is one type of glass which is resistant to break and reduces the risk of injury to the people if broken.
Safety glass types:
1- Laminated glass (shatterproof)
It consists of two or more layers of glass plates together with an interlayer (thin film of plastic) in between which are molten to each other under pressure. When laminated glass is broken, the broken pieces are held by an interlayer.
Note: Typically interlayer is layer of PVB (PolyVinyl Butyral).
Applications: Automobile windshield etc.
Note: Bulletproof glass is build up from several glass and various interlayers. Polycarbonate interlayer absorbs the energy of a bullet.
2- Tempered glass (toughened glass)
This type is build up using heat treatment method. Tempering increases the tensile strength. The glass sheets are tempered at about 650 °C and then are cooled rapidly. When glass is broken, it is divided into very small chunks of similar size and shape (blunt granules) which are relatively harmless fragments and reduce the possibility of injury.
Applications: shower doors, diving masks etc.
3- Wire mesh glass (wired glass):
It contains a grid (mesh) of thin metal wire embedded in the glass.
Applications: Fire rated doors and windows etc.
Related standards:
- ANSI Z.97.1
- EN 12150-1
- DIN 18032
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