Heat-Strengthened Glasses have 2 times increased mechanical strength, compared to the corresponding thickness of common glasses. In case the breaking limit is exceeded, then they break into large pieces with the result that the pieces are held in place. They also show greater resistance to temperature changes (up to 200°C), which makes them invulnerable to heat shock (from non-artificial means).
Heat-Strengthened Glasses have approximately (but not the same) properties as tempered glasses (securit):
- They show 2 times increased mechanical strength, in relation to the same thickness of ordinary glass.
- In case the breaking limit is exceeded, then they break into large pieces which most often end up in the perimeter where there is usually adhesive material with the result that the pieces are held in place.
- They do not have a safety rating (they are not considered safety glass)
- They are clearly more resistant to temperature changes (up to 200°C), which makes them invulnerable to heat shock (from non-artificial means).
Heat-Strengthened Glasses Applications
Heat-Strengthened glass, unlike tempered glass (securit), has no safety rating and so their applications are more limited.
The most common application is in glass curtains of very high buildings when there are no balconies. This happens for 2 reasons:
- It has increased mechanical strength and breaks much harder than ordinary glass either by impact or heat shock.
- In case of breakage, the breakage pattern ensures that the pieces remain in place held in place by the perimeter sealing adhesive.
A second important application is on railings and balconies when there is no support frame. In these cases the safest solution is to use a laminated glazing consisting of 2 panes one of which is Heat-Strengthened and the other Securit. This is because in the event of a break, the breaking pattern of the Heat-Strengthened glass will prevent the overall glass from folding, giving the person in time time to move away to a safe location.
Related Products
Thermally tempered glasses (Securit) focuses on tremendous fracture toughness (400% more durable than ordinary), thus offering "active" safety. In other words, they try to completely prevent the unpleasant consequences of the failure (breaking) of a glass.
Wired glasses were the first successful attempt by the glass industry to bring a safety product to the market.
The idea is very simple and was based on that of the construction of the well-known "reinforced concrete". Concrete as a material is very different from glass, but it has a great resemblance! While it is a very resistant material to compressive forces, it is extremely sensitive to tensile forces. The same thing happens with glass.
So since in the cement industry the solution to the problem was found by inserting iron bars (or mesh) into the cement when it is still in liquid form, the exact same solution was adopted in the glass industry.
Thus was born the idea of wired glass. Its construction in terms of composition and melting is exactly the same as that of ordinary glass. The differentiation is at the stage where the glass is still in liquid form and enters the setting phase. At that time, a stainless steel wire mesh is inserted into the liquid mixture, which after cooling the glass remains trapped in its mass.
Some types of glass can withstand the shockwaves of an explosion without shattering even though they are ultimately destroyed. Such glass can prevent serious bodily injury caused by flying shards of glass or other external debris.
This category of special glass meets safety and protection needs for premises where it is requested (banks, public buildings, museums, offices, etc.). The criteria which must be met by safety glass and the categories that are classified according to the level of protection provided, are controlled and measured using specific methodology as described in detail in the applicable international standards. Today, in European countries, the required standard for antivandalism glazing is the norm EN 356.
What has to be pointed is that the classification of glass into categories, based on European standards, is independent of their composition and depends exclusively on strength performance during the required tests.
These products are designed to have the capacity to absorb large amounts of impact momentum without bursting completely. The view does not differ from common glass equivalent thickness and so without the slightest aesthetic compromise,
it offers a transparent security barrier against most malicious actions.
The classification of types of bulletproof safety glass follows a nomenclature which corresponds to specific performance as checked/measured according to a specific methodology which are described in the European standard EN 1063.
“Smart” film alters from transparent to opaque in a laminated glass, simply, by the usage of electricity and a switch.
