What Materials Are in Bulletproof Vests?

Bulletproof vests are routinely worn by the military and police, to prevent bullets from penetrating their bodies. These vests generally cover the wearer's upper body, front and back. Some of them protect the sides as well. According to Body Armor News, an informative web site (ref 1), these vests are not actually bulletproof, because it is possible for them to be penetrated. A better term is "bullet resistant vests." Several materials are used in their manufacture.

Kevlar®

• Extremely strong, the synthetic material Kevlar® (a registered trademark of E.I. du Pont de Nemours) often fills the inside of bulletproof vests. It is a polymer, a chain consisting of a number of monomers (a group of similar molecules) bonded to one another. Examples of other man-made polymers include Teflon, nylon, polyester, and Lycra. The structure of polymers makes them strong, but Kevlar® is the strongest of these. Used for everything from supporting underwater structures (when Kevlar® is underwater it has 20 times the strength of steel) to sails for windsurfing, Kevlar® finds its way into many things. Its strength and light weight make it valuable in bulletproof vests.

Spectra Shield®

• Over the last 20 years, Spectra Shield®, a product developed by the Honeywell Company, has been replacing Kevlar® in many bulletproof vests in both military and police applications. Soft and lightweight, this fabric allows the wearer greater comfort and range of motion than Kevlar®. According to Honeywell, Spectra Shield's® formulation can be altered to create a hard, extremely strong material. Shaped into a plate and inserted into the front of the vest, it creates an almost impenetrable barrier.

Nylon and Cotton

• The Kevlar ® or Spectra Shield® lining forms the inner barrier of a bulletproof vest. The outer layer of the vest consists of either nylon or a polyester/cotton blend. Nylon padding provides comfort, and a layer of absorbent material, such as cotton, often covers the inside of the vest where it touches the wearer.

Ceramic and Metal

• In some cases, especially with bulletproof vests designed for the military, a protective ceramic or metal plate may be used over the chest. (ref 1) In some cases the vest permanently holds the plate. Other times the plate slips into a pocket over the chest. In the latter case the plate can be added as needed, such as just prior to entering a high-risk situation. Taking the plate out at low-risk times provides additional comfort for the wearer.