the history of bulletproof technology

A History of Bulletproof Technologywww.dovesteeldoors.co.uk0800 783 5745

http://www.dovesteeldoors.co.uk/

Bulletproof Technology- An Overview

Bulletproof glass has influenced the way workplaces, private citizens and troops are protected.

Bulletproof glass has many different names- ballistic glass, transparent armour, bullet-resistant glass.

It plays a major role in the protection of high profile individuals and high profile businesses as well as on the battlefield.


Bulletproof glass can be traced to a scientific experiment around 1625. At that time, a type of glass was developed that could withstand the swing of a hammer. It was named Prince Rupert’s Drops.

Edouard Benedictus accidentally developed the glass when he dropped a beaker of plastic cellulose nitrate and it didn’t shatter. This was an amazing discovery that advanced the possibility of bulletproof glass immeasurably.


The first mass use of bulletproof glass was during The Great War. The technology has come a long way since then and by 1939 bulletproof glass was used as armour for troops.

The most common misunderstanding made about bulletproof glass is that it is impenetrable. This is a myth, but the glass can resist a bullet and will crack rather than shatter.

The Evolution of Bulletproof Glass

Bulletproof glass is actually constructed with two or more layers of glass.

A hard glass is made to resist the bullet and a sifter layer is designed to add elasticity to the shield (which allows the glass to flex rather than shatter).

The index of refraction for all layers must have the same transparency capabilities to encourage visibility.


Typically, bulletproof glass ranges from three-quarters of an inch in thickness to as much as three inches (19mm-76mm).

A more recent development in bulletproof glass technology allows the glass to be tinted, making the precise location and identification of persons behind the plate difficult to assess. Many limousines used by statesmen use tinted bulletproof glass.


There are many historical instances where bulletproof glass might have diverted the course of man. Perhaps one of the more compelling was the decision by the security detail attached to John Fitzgerald Kennedy, President of the United States, to travel the streets of Dallas without his protection in 1963.

The Construction of Bulletproof Glass

Bulletproof glass is composed of polycarbonate thermoplastic and different layers of glass. The design is intended to provide the protected persons with a clear, accurate view of events and activities beyond the glass.

In some cases, heavy tinting is used to provide other security and privacy advantages.


Most bulletproof glass offer protection against small arms. Today, polycarbonate designs consist of varying products ranging from:

•Armormax

•Makroclear

•Cyrolon

•Lexan

•Tuffak


These products vary dependent on manufacturer but the theory is that they are intermingled between layers of regular glass.

The discovery of tempering has increased the bulletproof resistance capabilities of glass. This means that when the glass is heated or cold it is made stronger.


During the manufacturing process abrasive resistant coating is added. These coatings allow the glass to heal after being scratched.

The glass is named scratch resistant and these soft coatings are most often elastomeric carbon-based polymers or harder protective coatings made from silicon- based polymers.


For the most part, laminate designs are highly effective at resisting physical assault or abuse from hammers, axes, clubs and crowbars. However, these protective shields are not as effective against bullets.

When glass and these polymers are combined the results are more effective against bullets. A bullet striking glass usually flattens, then the plastic absorbs the impact and prevents penetration.


The ability of the polycarbonate layer to stop projectiles is directly related to the thickness and design of the product. Laminated glass layers consist of glass layers bonded with:

•polyvinyl butyral

•polyurethane or

•ethylene-vinyl acetate

Testing

Obviously, testing is important to the continuous advancement of the industry and to the protection qualities of bulletproof glass.

All bullet-resistant products are tested by firing a projectile into the shield. The test can be administered from various distances.

Testing

Interestingly, tests have shown that polycarbonate fails with projectiles at lower velocities. These polycarbonates are also more susceptible to regularly shaped projectiles than they are against irregularly shaped projectiles.

Testing

During testing, the depth of the penetration is closely observed, measured and corresponded to the projectile’s velocity and shape.

Tests have also shown that in extremely cold temperatures pieces of polycarbonate break off and become projectiles themselves.

For More Information

Contact Dove Steel Doors

Phone: 01384 22 11 44

www.dovesteeldoors.co.uk

Email: [email protected]

http://www.dovesteeldoors.co.uk/