Tempered glass

Broken phone box

CarWindowPolarization

Safeguard Glass Markings 1

HKPF Airport Police Patrol Car AM8599

Broken Meat Case Window

Tempered glass, also known as toughened glass, is a type of safety glass processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. The tempering process puts the outer surfaces into compression and the interior into tension. Such stresses cause the glass, when broken, to crumble into small granular chunks instead of splintering into jagged shards as plate glass (a.k.a. annealed glass) does. The granular chunks are less likely to cause injury.

Properties

Tempered glass is four to five times stronger than annealed glass of the same size and thickness against impacts. It has greater thermal resistance, and can withstand sudden changes in temperature. Tempered glass is also considered to be safety glass because it meets the requirements of various international standards for safety glass. This makes it suitable for use in environments where there is a high risk of impact or thermal shock.

Manufacturing Process

The manufacturing process involves heating the glass to over 600°C and then rapidly cooling it. This process, known as quenching, changes the physical properties of the glass and increases its strength. The rapid cooling puts the surfaces of the glass into compression and the interior into tension. This is what gives tempered glass its increased strength and what causes it to break into small, blunt pieces when shattered.

Applications

Tempered glass is used in a variety of applications where strength, thermal resistance, and safety are important. Common uses include:

• Automobile windshields and windows
• Shower doors
• Glass doors and glass panels in architecture
• Mobile phone screens
• Tableware and cookware
• Protective screens and barriers in public and industrial settings

Advantages and Disadvantages

Advantages

• Increased strength compared to non-tempered glass
• Breaks into small, less harmful pieces
• Can withstand thermal stresses and impacts

Disadvantages

• Once tempered, it cannot be cut or altered
• Can be more expensive than non-tempered glass
• The edges of tempered glass are more vulnerable to damage than the surface

Safety

The safety aspect of tempered glass is one of its most significant benefits. The small, blunt pieces it breaks into are less likely to cause serious injury compared to the sharp shards of broken annealed glass. This characteristic makes tempered glass an ideal choice for many safety-critical applications.

Maintenance

Tempered glass requires the same cleaning as regular glass. However, it is important to avoid using abrasive cleaners that can scratch the surface. Minor scratches can compromise the structural integrity of tempered glass.

See Also

• Laminated glass
• Glass production
• Safety standards

This article is a stub. You can help WikiMD by registering to expand it. Editing is available only to registered and verified users. WikiMD is a comprehensive, free health & wellness encyclopedia.