Poly (p-phenyleneterephtalamide)
C₁₄N₂O₂H₁₀

(Kevlar®)

   Kevlar is a type of plastic, similar to Nomex®. It is used for a variety of purposes, including car tire belts, white water rafting clothing and of course bulletproof vests. It comes either as a hard plastic sheet, where it can be used to make lightweight armour for vehicles or as a woven piece of cloth where it can be made into bulletproof vests. Stephanie Kwolek, Herbert Blades, and Paul W. Morgan developed it in 1965 at DuPont.

What makes it so strong?

There are three major reasons why Kevlar® is so much stronger than other plastics:

• Kevlar is made up of smaller sections called monomers linked together to form what is called a polymer
• Kevlar molecules are arranged in neat rows to make a crystalline polymer
• Kevlar molecules are connected by hydrogen bonds that are extremely strong

These factors combined make for an extremely strong plastic that is five times stronger than the same weight of steel.

What makes a bulletproof vest work?

   A soft bulletproof vest works with the same principle as a net. It works this way because distributes the force of the bullet over the entire vest. There are also many layers of fabric, each layer slowing the bullet down a little bit. This also causes the bullet to flatten out or “mushroom”. This helps to absorb more energy from the bullet. To help strengthen the vest the layers of fabric are sandwiched between layers of plastic resin.

   A hard bulletproof vest works much more simply than a soft bulletproof vest because it is basically the same thing that medieval knights wore.

Types of bulletproof vests

These are the different types of bulletproof vests available:

• Level 1 Body armour: soft body armour able to stop only low powered pistol rounds. This type of vest is worn when concealment and comfort are issues
• Level 2 Body armour: soft body armour able to stop most pistol rounds.- worn when decent protection is needed without a lot of extra weight.
• Level 3 body armour: usually hard body armour, although there is Level 3 soft body armour. It stops almost all pistol fire and low powered rifle fire.
• Level 4 body armour: This usually hard body armour can stop 99.9% of pistol rounds and most rounds from assault weapons.
• Level 5 body armour: hard body armour that stops almost all lead core full metal jacket rounds from an assault weapon
• Level 6-8 body armour: hard body armour used when extreme protection is required. Very restricting to movement.

Photo Gallery

This is a Level IIA soft bulletproof vest with pockets to put hard steel or ceramic plates to increase protection.

This is a suit currently being developed by DARPA(Defense Advanced Research Project Association)