When a handgun bullet strikes body armor, it is caught in a “web” of very strong fibers. These fibers absorb and disperse the impact energy that is transmitted to the bullet proof vest from the bullet, causing the bullet to deform or “mushroom.” Additional energy is absorbed by each successive layer of material in bullet proof vests, until such time as the bullet has been stopped.
Additional energy is absorbed by each successive layer of material in the ballistic panel.
Because the fibers work together both in the individual layer and with other layers of material in the vest, a large area of the bullet proof vest becomes involved in preventing the bullet from penetrating. This also helps in dissipating the forces which can cause nonpenetrating injuries (what is commonly referred to as “blunt trauma”) to internal organs. Unfortunately, at this time no material exists that would allow body armor to be constructed from a single ply of material.
Currently, today’s modern generation of concealable bullet proof vests can provide protection in a variety of levels designed to defeat most common low- and medium-energy handgun rounds. Bullet proof vests designed to defeat rifle fire is of either semirigid or rigid construction, typically incorporating hard materials such as ceramics and metals. Because of its weight and bulkiness, it is impractical for routine use by uniformed patrol officers and is reserved for use in tactical situations where it is worn externally for short periods of time when confronted with higher level threats.
Materials Used
Several manufacturers have been involved in developing and refining materials used in a bullet proof vest.
What are the different materials used in body armor? What material is best?
Just like any other product out there, body armor comes in many different makes and models, as well as many different ballistic materials. The best type of material comes down to your own personal needs.
Kevlar
Kevlar has been the longtime standard for ballistic material. It is 5x stronger than steel and is more flexible and comfortable than most other materials. It is tried, true, and battle proven. Kevlar is made by combining para-phenylenediamine and terephthaloyl chloride to create aromatic polyamide threads which are then refined and woven into the panels. Kevlar has saved thousands of lives and will continue to do so for a long time!
Polyethylene – Often Called PE or UHMWPE
This material is a relatively new to the ballistics market and is 5x the strength of steel. Polyethylene is a similar material to plastic shopping bags from the grocery store, but don't be fooled - ballistic UHMWPE is heavily engineered. UHMWPE is often found in cost effective body armor as it is generally much cheaper than other ballistic materials to produce.
Steel
Steel is a very cost effective material for hard armor. It is commonly used in hard rifle plates and is often used for targets.
Steel provides great protection and will stop multiple hits. HOWEVER, many people choose not to wear steel plates because they are not practical for daily use. Their weight makes wearing steel plates uncomfortable and significantly restricts movement. Standard 10x12 slabs of steel armor can weigh as much as 15 pounds, which means front and rear protection can weigh up to 30 lbs! The trade off between protection and comfort is at an extreme with steel. It is, however, a great material if you do not want to spend the money on a more advanced ballistic material. Remember, something is always better than nothing. If you are looking for the cheapest option, steel is a great choice.