A presentation on the discovery and development of modern bulletproof technology, including bullet-proof glass and ballistic doors.

1. A History of Bulletproof
Technology
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2. 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.

3. Bulletproof Technology- An Overview
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.

4. Bulletproof Technology- An Overview
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.

5. Bulletproof Technology- An Overview
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.

6. 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.

7. The Evolution of Bulletproof Glass
Typically, bulletproof glass ranges from three-quarters of
an inch in thickness to as much as three inches (19mm76mm).
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.

8. The Evolution of 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.

9. 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.

10. The Construction of Bulletproof Glass
Most bulletproof glass offer protection
against small arms. Today,
polycarbonate designs consist of
varying products ranging from:
•Armormax
•Makroclear
•Cyrolon
•Lexan
•Tuffak

11. The Construction of Bulletproof Glass
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.

12. The Construction of Bulletproof Glass
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 carbonbased polymers or harder
protective coatings made from
silicon- based polymers.

13. The Construction of Bulletproof Glass
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.

14. The Construction of Bulletproof Glass
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

15. 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.

16. 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.

17. 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.

18. For More Information
Contact Dove Steel Doors
Phone: 01384 22 11 44
www.dovesteeldoors.co.uk
Email: sales@dovesteeldoors.co.uk