If you are in the front line of a danger zone, preventing bullets from every direction, you will require all the help that you can get. This is when armored cars prove to be helpful as they are made of bulletproof glass. A bulletproof car can dissipate the energy of the bullet.
Reason Ordinary Glass Shatters
If you have ever played baseball or cricket, you will know that the trick to catch a fast-moving ball is to move your hand back and then gradually stop the ball. This way you reduce the energy slowly. This will reduce the force on your hand so that the catch hurts somewhat less. In scientific terms, the force which the ball exerts on the hand is pretty equal to the rate at which the momentum of the ball changes. Thus, if you change the momentum gradually simply by bringing it a halt slowly, the force will feel somewhat reduced. If you stop a ball almost instantly, you are going to feel a hefty smack on your hand. However, if you take your hands four times longer for bringing the ball to rest, your hand is going to feel quarter force. Thus, the ball is going to hurt you much less.
Unlike your hand, a piece of glass will not be able to move. If bullet is fired at an ordinary glass, the glass will not be able to bend to absorb the energy gradually. Thus, it will just shatters and the bullet will carry on without the loss of momentum. It is completely ineffective is slowing it down.
How to Make Bulletproof Glass?
Traditional bulletproof glass used in the armored cars is made of alternate layers of glass and plastic. Here, the plastic is thin film of PVB or polyvinyl butyric. New and strong bulletproof glass uses sandwich of plastic and glass which is made of acrylic glass, polycarbonate, ethylene vinyl acetate with the plastic layers and thick glass.
For making a simple PVB based shatterproof glass for armored cars, the thin PVB film is known to be compressed in between the thicker glass for making a laminate that is compressed and heated to that the plastic melts and beings bonding with the glass. This process usually happens in a vacuum for preventing the air from being trapped between the layers. The primary difficult with the process is to ensure that the glass and the plastic layers stick together properly without any air being trapped between them.
Where is the Bulletproof Glass Used?
Bulletproof glass comes in different shapes and sizes. It can be used for armored cars for protection. Thicker the glass and more layers it has, the more energy it can to absorb and more protection it will offer.
The only problem is the thicker the armored cars, the heavier it becomes. This will make it slightly more opaque.
Standards for Bulletproof Glass
Different standards exist in various parts of the world. Modern bulletproof glass is just a variation on the laminated safety glass. The primary idea is to use polyvinyl plastic in the laminated glass dates.