It may be called bulletproof glass, but it's often much more than just glass. Bulletproof glass can just as well be made of transparent plastics such as polycarbonate or acrylic. Or, ideally, a combination of glass and plastic, because this material mix stops bullets with outstanding efficiency.
Here we explain the different types of bullet proof glazing and what they are particularly suitable for.
There are two different methods of constructing bulletproof glass: symmetrical and asymmetrical. Since symmetrical bulletproof glass is identically structured from both sides, it stops bullets from both sides equally well. Logically. But most types of bulletproof glass are constructed asymmetrically, since this design stops projectiles more effectively using less material. As a result, bulletproof glass panes with an asymmetrical design are bullet proof from only one side, the attack side. For this reason, technicians must ensure correct orientation of the pane during installation. The attack side of the glazing faces the threat while the defense side faces the protected space.
|Bulletproof glass Symmetrical||Bulletproof glass Asymmetrical|
|Advantage||Bulletproof from both sides||Thinner and lighter than symmetrical|
|Disadvantage||Thicker and heavier than asymmetrical||Correct orientation is critical|
Glass and polycarbonate: The ideal combination for bulletproof glass, if you want to save a lot of weight and keep the glazing as thin as possible. In addition, these glass panes are crystal clear and free of the usual green tint. Of all the design principles for bulletproof glass, this is by far the best. Thanks to the low weight, windows can be opened easily. It is ideal for securing villas as well as public buildings. This is also because these panes offer additional protection against burglary compared to other bulletproof glass panes. SILATEC has been the world's leading manufacturer of bullet-proof glass-clad polycarbonate glazing for decades.
|Advantage||Thin, light, transparent, high burglary protection|
|Disadvantage||More complex to manufacture than conventional laminated armored glass|
Several sheets of glass are laminated together with a thin film until a thick glass pane is formed.
The thicker the glass construction, the greater its capacity to stop bullets. The disadvantage of this design principle is obvious. The thicker the bullet-proof pane is, the heavier it is. High weight of glass is particularly problematic for windows and doors, as the fittings can only bear limited weight. Another disadvantage: the thicker the glass, the more greenish it is. The view through the pane appears greener with increasing glass thickness. The break-in protection of these glass panes is low. It is possible to smash large holes through even 100mm (4") thick bullet-proof glass in less than a minute. For example, with a sledgehammer.
Is there bullet proof glass constructed of practically no glass at all? Yes. Such bulletproof panes consist purely of transparent plastics. Polycarbonate and PMMA, which is also known as acrylic glass, are used among other materials. Since these bullet proof panes are very light, they are used in special vehicles or construction machinery. The disadvantage is that these pure plastic solutions offer protection against handguns only. These bulletproof special solutions are virtually never used in buildings – especially in exterior glazing.
|Advantage||Generally somewhat less costly to produce|
|Disadvantage||Heavy, thick, greenish, generally offering no burglary protection|
|Disadvantage||Not suitable for exterior building applications. Generally protects against handguns only.|