The wonder of plastics.
ours is still kevlar
source: popularmechanics.com
When I hear the buzz phrase "improvised explosive device," I think of this kid I knew growing up. He was fascinated with explosives. One day while packing match heads into a pipe, he blasted a fist-size hole in his thigh. It ended happily enough. The doctors managed to save his leg. The improvised explosive devices (IEDs) being used against our troops in Iraq pack far more of a wallop. Instead of being fueled by kitchen matches, they typically consist of a pair of artillery shells that are set off by a remote-control detonator. Fortunately, the many soldiers who have crossed paths with Iraqi IEDs have been clad in armored jackets, and have had fast access to medical treatment. This has saved their lives. As the first year of the war draws to a close, the death toll stands at about 600. For the families and friends of each fallen soldier, the deaths are personal tragedies. For the Pentagon, the number of fatalities is astounding--astoundingly low.
Estimating casualties is as basic to the combat equation as estimating ammunition. During the Civil War, generals expected two soldiers would be wounded for every fighter killed. By the war in Afghanistan, the ratio of wounded to killed improved to about 3-to-1. Better medicine kept ahead of more powerful weapons. In Iraq, the ratio is an impressive 6-to-1. Body armor made a difference.
Higher Impact
Most of the 125,000 combatants stationed in Iraq have been issued Kevlar helmets and Kevlar vests with pockets that hold ceramic plates. And, from what military surgeons report, the armor seems to be working. When a group of orthopedic surgeons visited recovering soldiers in Walter Reed Hospital near Washington, D.C., in spring 2003, they were astonished at the low number of torso wounds. A full 80 percent of the life-threatening injuries were to the arms and legs.
However, months later, as the Army settled into its peacekeeping mission in Iraq, something unexpected happened. The insurgents traded their rifles for IEDs. High-explosive antitank rounds are now being used to attack "soft" civilian targets. The current generation of body armor, which was designed to withstand a blast from hand grenade fragments, is simply outgunned. Help is at hand. In fact, you probably held the solution to the IED problem in your hand the last time you went shopping.
Invisible Chains
Lori Wagner, manager of the Spectra products division at Honeywell, hands me a sheet of what feels like wax paper. Beneath the film that gives it its slippery coating are rows of tightly packed, high molecular weight polyethylene.
In grocery bags, lower-weight fibers are disorganized. In Spectra fabrics, fibers line up in overlapping parallel rows. "We have captured the tremendous natural strength in the molecular backbone of this material to create one of the world's strongest and lightest fibers," Wagner explains.
Pound for pound, Spectra is 10 times stronger than steel.
"Because of its molecular makeup, Spectra fiber resists the penetrating force of a projectile, rapidly moving the kinetic energy of the bullet away from the impact area and ultimately slowing the projectile to a stop," Wagner says.
In the coming months the Army will be testing vests made with the ultradense plastic.
If Spectra-Shield performs as successfully against IEDs as it has in laboratory tests, it could find its way into civilian products. Efforts are also under way to use it in commercial airliners. It can prevent explosives hidden in cargo from breaking apart a plane's fuselage, as happened when a terrorist bomb exploded on Pan Am Flight 103 over Lockerbie, Scotland. Honeywell also sees a market in bulletproofing limousines.