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.