Armored Bulletproof and Ballistic Glass

High-Tech Modular Cost Effective Vehicle Armor

Glass

Bullet Proof Glass

Strictly, bulletproof glass would be glass that is capable of stopping most manner of bullets fired at it. Such glass cannot currently be made in any usable thickness (if at all), so what is loosely called bulletproof glass is, within the industry, referred to as bullet-resistant glass.

Bullet-resistant glass is usually constructed using a strong but transparent material such as polycarbonate thermoplastic or by using layers of laminated glass. The desired result is a material with an appearance and light-transmitting behavior of standard glass but offers varying degrees of protection from small arms fire.

The polycarbonate layer, usually consisting of products such as Cyrolon, Lexan and Tuffak, is often sandwiched between layers of regular glass. The use of plastic in the laminate provides impact-resistance, such as physical assault with a hammer, an axe, etc. The plastic provides little in the way of bullet-resistance. The glass, which is much harder than plastic, flattens the bullet and thereby prevents penetration. This type of bullet-resistant glass is usually 70–75 mm (2.8–3.0 in) thick.

Bullet-resistant glass constructed of laminated glass layers is built from glass sheets bonded together with polyvinyl butyral or polyurethane. This type of bullet-resistant glass has been in regular use on combat vehicles since World War II; it is typically about 100–120 mm (3.9–4.7 in) thick and is usually extremely heavy.

Ballistic Glass

This is a multilayer “sandwich” with the glass facing outside and the poly as the inner surface: as the projectile proceeds the different layers act like a catcher’s mitt in slowing down the round and then physically catching it in one of the layers. This is why B4 glass is typically 21-24mm thick and B6 is 41-44 mm.

1. Glass with ceramic frit: This is the outer sheet of glass that looks very much like the original equipment glass in both shape and size.

2. PVB: This is the adhesive innerlayer between sheets of glass.

3. Glass: Second sheet of glass.

4. PVB: This is the adhesive inner layer between sheets of glass.

5. Glass: Third sheet of glass.

6. PVB: This is the adhesive inner layer between sheets of glass.

7. Glass: Fourth and last sheet of glass. It is cut smaller and forms the
channel that will innerlock with a similar mating hard armor frame surrounding the door.

8. Polyurethane: This is the adhesive inner layer between glass and the polycarbonate which act as an anti spall shield.

9. Polycarbonate with abrasive resistant coating: The polycarbonate acts as an antispall shield.

Are you are wondering what the bulge is???

The glass composition used by most major ballistic glass makers puts glass on the outside layer, several layers of glass and poly vinyl buteral in the middle, next polyurethane, and finally polycarbonate.

The benefit of this method is the ability
of the polycarbonate to expand and "catch" the fragments created by the harder glass surfaces. Expansion in excess of two inches is possible.

This is an example of a German DIN optics test on a windscreen. A special grid is projected through the windscreen at the same angle as a driver would be viewing it. Any distortion in the glass will result in waviness of the lines projected on the screen.

This waviness can be measured and the optical quality of the glass determined in an objective and quantitative way. Looking through a distorted windscreen at night or in bright sunlight is similar to using the wrong prescription glasses. If the driver is distracted by poor optics, safety of the vehicle and passengers is compromised.

Visual acuity is crucial in everyday conditions and the results can be catastrophic under attack if not up to standard.