You can get a strong and durable armored ballistic resistant glass by Sandwiching layered polycarbonate between the two sheets of glass. The glass that uses glass-clad polycarbonate can stop AK or M 16 ammunition. Therefore, it is used in dangerous zones such as areas prone to explosions, dangerous weather, and other impact intrusions.
Manufacturers use different polycarbonate plastics to form the middle layer of the glass. Makroclear and cryolon are two common types of polycarbonate plastics.
These layers of plastic truly decrease the momentum of the bullets. Polycarbonate bullet-resistant glass can protect against a variety of weapons ranging from handguns to extremely powerful rifles. For example, B5 level glass with 1-inch thickness can sustain.
Increasing the thickness and durability of the glass might decrease the ability to transmit light. Light transmission and the weight of the glass are essential for practical reasons.
Therefore, manufacturers not only consider the strength of the material but also the optical clarity of the glass. Acrylic and polycarbonate offer both these characteristics.
Glass and plastic are the two primary components of bullet-resistant glass. A simple bulletproof glass contains 3 layers i. Thin layers of an optical-clear and tough plastic, known as PVB, are sandwiched between sheets of standard glass.
Polyurethane and ethylene-vinyl acetate are other laminated materials. These layers are bonded together with heat. For strengthening the bond, the temperature should be up to o C. And, apply pressure nearly 13 to 14 times more than atmospheric pressure in an autoclave.
At this temperature and pressure, the melted plastic makes a strong bond with the glass. Why does a bullet shatter an ordinary glass?
Well, there is a huge difference between both types of glass. Why does an ordinary glass shatter? The normal glass comes with a car from the factory, is only 3mm thick and fragile. The bullet fractures it along the line of weakness so the glass is shattered as a result. Glass fragments and shards can be more dangerous than bullets. Because you might be safe from bullets but these broken pieces of glasses can kill you. In such situations, bulletproof glass can be safer for you.
Contrary to ordinary glass, bullet-resistant glass reduces the speed of the bullet gradually. Because it is made of multiple layers of glass and interlayers of plastics. It also contains a plastic final layer to prevent the spalling of glass upon breakage. Inner plastic layers of this security glass keep absorbing the energy of the bullet.
As a result, the inner layer of polycarbonate extensively break down the speed of the projectile and minimize the damage. The portrayals in Hollywood movies of bulletproof glass being fired upon and the bullets simply bouncing off, with no damage to the glass, are simply inaccurate.
For a more realistic portrayal of ballistic glass being fired on, check out this video. In fact, ballistic glass is made from several layers of clear or tinted glass covered with safety films to prevent spall , adhesive interlayers, and layers of high-quality polycarbonate, a plastic similar to plexiglass.
The polycarbonate is what gives it the strength to withstand the high-velocity impact. Ballistic glass is rated for its strength and resistance to bullets. Level 1 is engineered to withstand three shots from a 9 mm handgun, while Level 8 is made to hold up to five shots from a rifle firing a 7.
Given this vast difference in effectiveness, it is important to know what level any ballistic glass is before trusting that it will hold up under fire. There are two types of bullet resistant glass — solid acrylic and laminated polycarbonate. Laminated polycarbonate is made by layering polycarbonate, a heavy-duty clear plastic, between two sheets of glass and laminating it all together. The newest form of bullet resistant glass is one-way bulletproof glass, commonly used in armored vehicles.
One-way bulletproof glass is composed of two layers. The outside layer — on the threat side — is made of a brittle glass and the inside layer is a flexible polycarbonate. A bullet that strikes the brittle external layer first causes the glass to break inward toward the polycarbonate layer. Bullets shot from the inside of an armored car are able to penetrate the bullet resistant glass because they strike the polycarbonate layer first with more focused energy.
The brittle glass layer then breaks outward allowing the bullet to pass through with minor energy loss. Share this Post. This gives a person being shot at the ability to shoot back. This type of bullet-resistant glass is made by laminating a brittle sheet of material with a flexible material.
Imagine a car equipped with this one-way bullet-resistant glass. If a person outside the car shoots a bullet into the window, the bullet would strike the brittle side first. This brittle material would shatter around the point of impact and absorb some of the energy over a large area. The flexible material then absorbs the remaining energy of the bullet, stopping the bullet.
A bullet fired from inside the same car would easily pass through the glass because the bullet's force is concentrated on a small area, which causes the material to flex.
This causes the brittle material to break outwards, allowing the bullet to pierce the flexible material and strike its target.
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