An Iraq success story: SAPI plates (GNFI)

Stars & Stripes ^ | 31 Jan 04 | Lisa Burgess

[xzins]

An Iraq success story: SAPI plates

By Lisa Burgess, Stars and Stripes European edition, Saturday, January 31, 2004

ARLINGTON, Va. — The military’s new Interceptor body armor has proved to be one of the major success stories of the campaign in Iraq, with everyone from combat medics to Defense Secretary Donald Rumsfeld singing its praises.

Most soldiers know that the key to the armor’s bulletproof qualities are the so-called “SAPI” plates, for Small Arms Protective Inserts.

The two four-pound plates, which fit into pockets sewn into the front and back of the outer vest, can each stop shrapnel from mortar and grenade explosions, as well as 7.62 mm AK-47 rifle rounds.

But surprisingly, the quarter-inch layer of white backing on the plates, which looks like plastic to an untrained eye, is as much responsible for the SAPI’s stopping power as the ceramic composite it backs.

That backing isn’t really plastic at all. It’s Spectra Shield, a patented “carbon-chain polyethylene that is the lightest, strongest fiber in the world,” according to Lori Wagner, manager of Spectra Technology Performance Products, part of Honeywell’s Specialty Materials division in Colonial Heights, Va.

Pound for pound, Spectra is 10 times stronger than steel, Wagner, who has a doctorate in chemical engineering, said in a recent interview with Stripes.

The SAPI’s ceramic composite and Spectra backing work in tandem.

First, the ceramic absorbs the initial impact of an incoming bullet or fragment.

“But all the ceramic does is provide a broad surface that can break, deform or turn the bullet,” Wagner said.

So that’s where the backing comes in. The Spectra absorbs the projectile’s energy and spreads it along the surface of the shield, preventing fragments from penetrating the soldier’s body, she said.

The material works the way it does largely because it’s made of carbon, which has a simple molecular structure, Wagner said.

“There’s nothing hanging on the outside” of the carbon molecule, Wagner said. “Simplest is best, in this case.”

After engineers form carbon into long chains, using a process called “gel spinning,” the strands can be packed and stacked with virtually no space in between, Wagner said — in effect, like a “net” with no holes for anything, such as a bullet, to sneak through.

Honeywell engineers are now working on the next generation of Spectra, which they hope will be “a quantum leap forward” in stopping power, Wagner said.

Meanwhile, Honeywell is working to develop other military applications for Spectra, Tim Swinger, Spectra’s global marketing manager for armor, said during the interview.

The Marine Corps is working with Honeywell on using Spectra as armor for its Expeditionary Fighting Vehicle, and the Army is evaluating Spectra as armor for Humvees, Swinger said.

The Army already uses the material aboard some of its Apache helicopters, and may expand onto the Comanche.

The Air Force and Navy, meanwhile, are interested in making lightweight blast-protection containers out of Spectra, so ordnance can be transported more safely, Swinger said.

But for now, knowing that their material is saving lives in Iraq offers Spectra engineers a tremendous sense of satisfaction, Swinger said.

“It makes you want to go in to work every day,” he said. “My wife wonders why I work so much, but it’s because you know you’re helping save someone’s life.”

[xzins]

GNFI Spectra Shield ping!

The two four-pound plates, which fit into pockets sewn into the front and back of the outer vest, can each stop shrapnel from mortar and grenade explosions, as well as 7.62 mm AK-47 rifle rounds. But surprisingly, the quarter-inch layer of white backing on the plates, which looks like plastic to an untrained eye, is as much responsible for the SAPI’s stopping power as the ceramic composite it backs. That backing isn’t really plastic at all. It’s Spectra Shield, a patented “carbon-chain polyethylene that is the lightest, strongest fiber in the world,” according to Lori Wagner, manager of Spectra Technology Performance Products, part of Honeywell’s Specialty Materials division in Colonial Heights, Va. Pound for pound, Spectra is 10 times stronger than steel, Wagner, who has a doctorate in chemical engineering, said in a recent interview with Stripes.

[Travis McGee]

They make sailboat sails and ropes out of it too.

[xzins]

I had never heard of Spectra before, but I'd heard of the new ceramic plates. I'd wondered what the deal was.

This is good stuff.

[SAMWolf]

Bump

[Ernest_at_the_Beach]

Build more factories!

[VOA]

bump

[Ragtime Cowgirl]

Very good news, bump!

[Ernest_at_the_Beach]

Bulldog Direct Protective Systems Inc.

Spectra Shield © is the strongest, lightest, composite ballistic material made today! Spectra Shield © isn't a woven fabric like most ballistic materials i.e. [ Kevlar©] used today! But instead, a thin,flexible ballistic composite made from two layers of unidirectional fibers held in place by flexible resins.  These fibers are arranged so they cross each other at 0 and 90 degree angles, then, both fiber and resin layers are sealed between two thin sheets of polyethylene film similar to sarran wrap. Spectra Shield is ten times stronger than steel. 

Spectra Shield composite armor panels are readily cut and fabricated using commonly available tools [saber saw with a knife blade will easily cut the panels.]  The panels can then be glued in place, or installed with screws, nuts and bolts, etc.  Butt joints are ballistically weak, reinforce them with a min. 4" wide strip of same level of material to cover any gaps in the panels.   

Threat	Level Of Protection	Thickness	lbs.per sq.ft.
.9mm,, .357 Magnum Handguns And lesser threats	N.I.J. II	5/32"	0.8 lbs.
.9mm,, .357,& ,.44 Magnum Handguns And lesser threats	N.I.J. IIIA	7/32"	1.0 lbs.
.5.56mm 55 gr., 30 cal 180 gr.,308 NATO 150 gr. And lesser threats	N.I.J. III	11/16"	4.75 lbs.
.5.56MM SS 109, AK-47 [7.62x39] And lesser threats]	*N.I.J. III+	1-7/64"	7.5 lbs.

 * Spectra Shield plus 1/8" steel plate 

[xzins]

Great info, Ernest. Thanks.

[Wonder Warthog]

"That backing isn’t really plastic at all. It’s Spectra Shield, a patented “carbon-chain polyethylene that is the lightest, strongest fiber in the world,” according to Lori Wagner, manager of Spectra Technology Performance Products, part of Honeywell’s Specialty Materials division in Colonial Heights, Va. Pound for pound, Spectra is 10 times stronger than steel, Wagner, who has a doctorate in chemical engineering, said in a recent interview with Stripes."

Obviously, "Dr" Wagner, chemical engineer, must not have listened very well in his chemistry classes. Polyethylene IS a plastic---in fiber form or not.

[xzins]

If either of you know anything about chemical engineering, then I ain't arguin' with either of ya!

[Ernest_at_the_Beach]

So what does carbon chain do for it?

[Wonder Warthog]

"So what does carbon chain do for it?"

The "carbon chain" is the carbon-carbon "backbone" of the polyethylene polymer. The unique thing here seems to be the spinning of the polyethylene into very fine (and probably highly oriented) polymer strands, not the polymeric material itself.

Of course, given the fact that most "journalists" totally garble the science in news stories, there may be critical facts missing.

[Alamo-Girl]

Bump!

[windchime]

Bump!

[Grampa Dave]

We fly fishers who fish for big ocean fish or salmon have been using Spectra flyline backing for a few years.

I can put on 300 yards of Spectra flyline backing rated at 35 lb test (breaking strength) on my bigger reels that would be maxed out with less than 200 yards of 30 # test flyline backing.

This Spectra flyline backing saved my oldest son's fly line and maybe his ocean flyrod and reel last summer. He was Albacore fishing, and the first fish struck his fly and went out and down about 400 yards in a flash. He had another 100 yards of Spectra Backing, and he was able land this fish and several of its brothers and sisters thanks to the Spectra fly line backing. The extra 100 plus yards of Spectra fly line backing was the safety cushion for that trip and a trip to Cabo for him.

When we retrofitted our church to prevent Earthquake damage, some form of Spectra was sprayed on the outer walls before they were painted. The paint had something like Spectra in it. The Project Manager said that the Sprayed on stuff and special paint provided more strength that the girders. We had zero damage on the walls during the labor day earthquake 3 years ago. The job was completed a couple of months before.


This is great stuff, and I'm really glad to see that our troops are getting it to wear.

[xzins]

Great stories and info!

Thanks.