Toughened glass (also known as tempered glass) is an extremely strong glass which has been thermally heat treated to induce compressive stresses of 11000 to 20000 psi on the surfaces and edge compression of not less than 9700 psi.

Toughened glass is being used increasingly in architecture because of its strength and safety properties. It is usually installed in areas where safety glass is required to reduce the possibility of mechanical or thermal breakage and/ or to assure greater uniform load strength. Worldwide the use of Toughened glass or Safety glass in general has been mandated by building codes. These codes are also made for India and are in the process of being mandated.

Due to the inherent superior features of Toughened Glass, like more strength, ability to withstand sudden impacts and breaking into small pieces, it is considered as a safety glazing and so in most countries, use of Architectural Toughened Glass is mandatory for entrances in public areas or where it is to be used by general public.

Process of Manufacture

Cut to size, glass sheets are electrically heated in the furnace where it oscillates back and forth on rollers till glass reaches temperature of about 680°c. The heating is done very evenly with highly advanced control systems and it takes 40 to 60 seconds per mm of glass thickness to achieve and stabilize at this set temperature. At this temperature it becomes very soft and flexible. From the furnace the glass is transported on roller conveyor and rapidly cooled in quench section by a blast of air on both sides of the glass. Sudden cooling or quenching after uniform heating induces compressive and tensile stresses that impart strength to the glass. Outer surface is under compressive stress while inside or core is under tensile stresses.

Advantages of Toughened Glass

Strong
     Toughened glass is 4-5 times stronger than normal annealed glass.

High Thermal Shock Strngth
     Ability to withstand high temperature variations upto 250°c.

Wind Loads
     Used in building facades as it have the ability to withstand heavy wind loads.

Safe
     Breaks into small, relatively harmless fragments. This reduces the likelihood of injury as there are no jagged edges or sharp corners.

Range Available

Available in 4, 5, 6, 8, 10, 12, 15, 19 mm thickness.
Maximum Size : 2440 X 3660 mm.
Minimum Size : 220 mm diagonal.
Colors : Clear, Bronze, Gray, Green, Blue, Reflective & Low-E.

TOUGHENED GLASS Vs ANNEALED GLASS

TOUGHENED GLASS

Tempered glass(also known as toughened glass) is an extremely strong glass which has been thermally heat treated to induce compressive stresses of 10,000 to 20,000 psi on the surfaces and edge compression of not less than 9700 psi.
Tempered glass provides greater thermal strength. It offers increased resistance to both sudden temperature changes and temperature differentials up to 240°c.
Tempered glass is very difficult to break but even on breakage, it will break into small, relatively harmless fragments with no jagged edges or sharp corners.

ANNEALED GLASS

Annealed glass is the most common type of glass which is generally available on the retail shops and it is not considered as a high performance product.
It provide much lesser thermal strength and can withstand temperature differentials up to 40°c only.
It can easily break and it will break into larger pieces contains jagged edges or sharp corners which may lead to serious injuries.

APPLICATION OF TOUGHENED GLASSES
Glass Doors
Glass for Shower Cubicals
Glass for Facades
Glass for Windows
Glass for Stairs
Glass Partitions>
Glass for Railings
Glass Walkways
Glass for Squash Courts
Glass for Lighting Fixtures
Glass for Kitchen Appliances
Glass for Furnitures
Glass for Automobiles

Heat strengthened glass is a semi Toughened glass, which has been strengthened thermaly by inducing a surface compression of 6000 to 9000 psi as compared to a range of 11000 to 20000 psi in case of fully Toughened glass. It is two times stronger than annealed glass. Though it is not considered to be a safety glass, it is widely used on building facades due to better optics.

TOUGHENED GLASS Vs HEAT STRENGTHENED GLASS

TOUGHENED GLASS

Four to five times stronger than normal annealed glass.
Toughened glass is very difficult to break but even on breakage, it will break into small and harmless fragments.
Toughened glass will resist temperature difference of up to 240°c.
In comparison with Heat Strengthened Glass, Toughened glass can break spontaneously.

HEAT STRENGTHENED GLASS

Heat Strengthened Glass is twice as tough as annealed glass but nearly half of fully tempered glass.
Heat Strengthened Glass has a comparatively flatter finish than fully tempered glass. It therefore has lesser optical distortions.
Heat Strengthened Glass breaks in a manner similar to that of float glass.
Heat Strengthened Glass will resist temperature difference of up to 130°c.
In comparison with Toughened Glass, Heat Strengthened Glass is not easily broken spontaneously.

FEATURE

Strong
     Heat Strengthened Glass is 2 times stronger than normal annealed glass.

Safety
     The fragments tends to remain in sashes and having less probability of fallout.

Optics
     Heat Strengthened Glass has flatter finish and has lesser optical distortions

No Thermal Breakage
     Heat Strengthened Glass will resist temperature difference of up to approximately 130°c.


Range Available

Maximum size : 2440 mm X 3660 mm
Minimum size : 220 mm diagonals
Thickness range : 4 mm to 19 mm
Colors : Clear, Bronze, Gray, Green, Blue, Reflective & Low-E

APPLICATONS OF HEAT STRENGTHENED GLASS
Canopies
Skylight
Facades
Security Laminates

( EVA : Ethylene - vinyl acetate )

Laminated glass is two or more panes of glass with one or more layers of ethylene vinyl acetate (EVA) sandwiched between them and treated. The glass panes can be basic float glass or tempered or heat strengthened panel. If the glass is broken, fragments tend to adhere to the EVA inter layer thereby reducing the risk injury from falling glass and helping to resist further impact or weather damage. It is most suitable wherever safety, security, noise control or UV control is a requirement. It has been partly taking the places of PVB film in laminated safety glass, laminated art glass, laminated color glass. Glass can also be laminated with special like - Colored EVA in transparent, translucent and opaque; Acoustic EVA for improved acoustic performance and Laminated Glass for better structural strength.

What is EVA?

EVA stands for Ethylene Vinyl Acetate.
It is a thermoplastic copolymer resin.
EVA resin, together with a number of ingredients, is heated and mixed thoroughly and is then extruded through a flat die of a special design plastic extruding machine.
EVA film is then formed. It is finally wind up in roll for storage and packing.
This extraordinary adhesive film is non-sticky and inert to water moisture.
Handling and glass assembly could be done under room temperature. No air conditioner and no de-humidifier are required.

EVA Instead of PVB

It Is Proved To Be One of the Best Alternatives to Costly PVB

Traditional glass lamination and encapsulation is made by sandwiching PVB interlayer film in between two pieces of glass.
It is then final bonded with autoclave. EVA glass lamination could be done without autoclave.
This new type of process requires also no roller press, no vacuum bags and no rubber rings.
Similar to PVB, EVA is also sandwiched in between two pieces of glass.
Thanks to the advance and update technology process, however, production equipments and relevant process for EVA glass lamination is much easier and simple than conventionally PVB lamination.
Only one single machine is required to fabricate EVA laminated glass.

EVA Becomes Popular

More Glass Fabricators Employ EVA to Be the Priority Interlayer for Glass Lamination and Encapsulation

As glass design for furnishing, decoration and building becomes more and more sophisticated, versatile glass with better aesthetic visual effect and functions are required drastically at low cost.
EVA laminated glass meets the requests that simply could not be done or at high cost previously.
As more designers are well aware the versatility of EVA laminated glass, it is getting more popular.
EVA laminated glass begins to play significant role for architects, interior and environmental designers.

EVA Classifications
Available in 3 Kinds of Thickness

0.25 mm
0.38 mm
0.76 mm
Available in 30 Colors and Transparencies

From standard clear to super clear
From light white to deep white
From transparent red to transparent black
From translucent orange to translucent blue
From opaque yellow to opaque purple
Available For Versatile Applications

Furnishing, decoration and architectural for both general purpose and outdoor purpose.
Encapsulation for special types of glass such as PDLC smart, intelligent and privacy glass.
Encapsulation for photovoltaic solar panel.
Insulated glazing (IG), more commonly known as double glazing (or double-pane, and increasingly triple glazing/pane) is double or triple glass window panes separated by a vacuum or other gas filled space to reduce heat transfer across a part of the building envelope. Insulated glass units are manufactured with glass in range of thickness from 3 mm to 10 mm (1/8" to 3/8") or more in special applications. Laminated or tempered glass may also be used as part of the construction. Most units are manufactured with the same thickness of glass used on both panes but special applications such as acoustic attenuation or security may require wide ranges of thicknesses to be incorporated in the same unit.

Thermal performance
The maximum insulating efficiency of a standard IGU is determined by the thickness of the space. Typically, most sealed units achieve maximum insulating values using a space of 16–19 mm (0.63–0.75 in) when measured at the centre of the IGU. An older-established way to improve insulation performance is to replace air in the space with a lower thermal conductivity gas. Gas convective heat transfer is a function of viscosity and specific heat.

Acoustic insulating properties
In some situations the insulation is in reference to noise mitigation. In these circumstances a large air space improves the noise insulation quality or Sound transmission class. Asymmetric double glazing, using different thicknesses of glass rather than the conventional symmetrical systems (equal glass thicknesses used for both sides) will improve the acoustic attenuation properties of the IGU. The most widely used glazing configurations for sound dampening include laminated glass with varied thickness of the interlayer and thickness of the glass.

Longevity
The life of an IGU varies depending on the quality of materials used, size of gap between inner and outer pane, temperature differences, workmanship and location of installation both in terms of facing direction and geographic location, as well as the treatment the unit receives.

FEATURE
Insulation
Saves on heating and cooling by reducing air to air heat transfer.

Prevention of Dew Condensation
There is no dew formation on the glass surface permitting a clear view even in the most humid conditions.

Retards Sound Transmission
Using one of the panes as laminated glass will drastically reduce sound transmission.

Pleasant Room Temperature
It offers increased personal comfort even when seated next to the glazing as the temperature of the inner pane is close to room temperature maintained.

Strength
DGU glass will marginally increase the overall strength against wind load pressure.

Multiple Glass Combinations
There are one or more panes of glass should be laminated or toughened within the insulated glass.