At first glance, bulletproof glass looks like any other pane of glass. But looks can be deceiving. This tough material is actually made up of multiple layers of glass and plastic, designed to absorb the impact of a bullet.
Armored vehicles often use bulletproof glass to protect passengers from attack. The windows in these vehicles are usually several inches thick and can stop bullets, ranging from small caliber handguns to high-powered rifle rounds.
How It Works
In movies, bulletproof glass resists all sorts of firepower, from pistols to machine guns. Sometimes, it might even go as far as stopping a rocket-propelled grenade. But in the real world, “bulletproof” glass is a bit of a misnomer. A more appropriate term is “bullet-resistant” glass.
That’s because no material can completely stop a bullet–not even steel. However, by layering multiple sheets of glass and plastic, “bulletproof” glass can absorb the impact of a bullet and prevent it from penetrating the material.
The Science Behind Bulletproof Glass
When you see a bulletproof window in an armored car or bank lobby, it looks like a single sheet of glass. But it’s actually layers of material bonded together to create a strong and impact-resistant barrier.
The exact composition of bulletproof glass varies based on ballistic performance requirements. But typically, the material consists of two or more layers of glass, separated by a layer of plastic. This is what makes it less likely to shatter on impact.
When a bullet hits the glass, the energy of the impact spreads out over a larger area. All the layers of glass and plastic slow down the bullet, dissipating its power so that it doesn’t penetrate the material.
While bulletproof glass can stop most small bullets, larger rounds can cause the material to crack or shatter. That’s why armored vehicles usually have windows that are thicker than the typical windows on cars. The extra layers of glass and plastic provide additional protection against high-powered rifle rounds.
Bulletproof Glass in Armored Cars
In the event of an attack, the driver and passengers can stay safe inside the vehicle while the glass absorbs the impact of the bullets, rocks, or other debris thrown at the car.
The thickened, multi-layer windows in armored cars provide a high level of protection against small caliber handguns and high-powered rifle rounds. The glass is also treated with a coating to make it harder and less likely to shatter on impact.
While bulletproof glass can’t stop every type of attack, it’s an essential layer of security for armored vehicles. So, remember the science behind this life-saving material the next time you see a bulletproof window.
The Takeaway
Bulletproof glass, bullet-resistant glass, or even energy-absorbing glass–no matter what you call it, it works the same. This life-saving material has several layers of sheets of plastic and glass designed to absorb the impact of a bullet. They distribute the energy of the impact over a larger area, slowing down and preventing the bullet from penetrating the material. The thicker the glass, the more layers of protection.