Protecting Our Troops — with Wool
When you think of all the folks whose job it is to try to protect our troops and keep them from harm, here's one group that probably doesn't immediately come to mind: the scientists of the Agricultural Research Service (ARS).
Actually, the scientists of ARS have a long history of protecting the military, going back to the days just before World War II, when the Army asked the ARS scientists to come up with a more productive strain of penicillin so that sufficient quantities would be available to treat combat wounds. ARS-developed technologies have helped our armed forces fend off a whole array of pests, such as lice that spread typhus or the sand flies whose bites lead to the horrible wounds known to our troops in Iraq as "Baghdad boil."
A while back, ARS scientists in Pennsylvania developed an amazing "biopolishing" method that can make scratchy wool feel smooth as silk. The process also makes the wool washable, shrink-proof, more durable and easier to dye.
Now those scientists have gone a step further and developed a way to make wool less susceptible to burning. That makes it an ideal fabric for uniforms worn not only by the military, but also by firefighters and others whose occupation exposes them to fire.
Wool burns with a self-extinguishing flame and turns into a soft ash. By contrast, some military garments currently are made of synthetic fabrics that, as they burn, melt into hard little beads that can drip into a wound and cause harm.
At the ARS lab in Pennsylvania, the scientists discovered and patented a heat-resistant material that can be incorporated into wool and other fabrics to give them as much flame resistance as that offered by commercial firefighters' uniforms. This technique was developed by the ARS scientists at the request of the U.S. military, one of the largest markets for domestic wool, to give our troops protection against fire-related injuries.
The ARS scientists improved the flame resistance of their biopolished wool by treating it with a heat-resistant polymer that's stable, easy to process, and highly tolerant of extreme temperatures. Unlike some popular flame retardants, the ARS material doesn't use the heavy metal zirconium, which can cause health hazards during processing. The polymer can also be used to treat natural, synthetic and blended fibers, but wool is particularly suitable because of its natural fire resistance.
Prepare to be impressed: Preliminary tests have shown that the burning behavior of ARS' polymer-treated wool is comparable to that of a 50/50 blend of wool and Nomex, the fabric that's currently used in protective firefighting gear.
Now the ARS scientists are experimenting with different methods to enhance the wool's heat-resistant and flame-retardant properties. Also, they say the flame-retardant treatment should stand up well to repeated laundering.
The ARS scientists' earlier accomplishments with biopolishing of wool have found eager customers. So far, nine companies have expressed interest in obtaining a license to use this patented technology, and the ARS Office of Technology Transfer has already issued two licenses for it.
The biopolishing removes the wool fiber's spiky tips, so the wool feels less scratchy. Also, the scientists use bleach to dissolve a protective fat layer wrapped around the wool fiber, leaving behind a lighter-colored fiber that's more receptive to dye.
That's why the biopolished wool could lead to longer-lasting garments. Typically, high temperatures are needed to dye wool — to get past that fat layer — and those high temperatures can weaken the fiber. With the fat layer out of the way, the wool can be dyed at cooler temperatures.
The biopolishing also includes an enzyme treatment that makes the wool machine-washable. The surface of a wool fiber is covered with a multitude of tiny scales, similar to fish scales, and when standard wool is washed, the heat and pressure cause those scales to tightly lock together. But the enzyme treatment breaks down those scales so they can't lock up. Normally that layer of fat that I mentioned earlier would protect the scales against the action of the enzymes, but the bleaching step eliminates that fat layer.
So there you have it: wool that's truly washable, silky-smooth, easy to color, and flame-resistant!
"Everybody's
Science" is written by Sandy Miller Hays, Director of Information for
the Agricultural Research Service, the chief scientific research agency
of the U.S. Department of Agriculture. Hays is a native of Fort Smith,
Ark. From the late 1970s until early 1988, Hays was a reporter, editor
and columnist at the Arkansas Democrat (now the Arkansas Democrat-Gazette),
a Little Rock-based daily newspaper. She joined the ARS Information
Staff in 1988, and became Director of Information in April 1998.
When you think of all the folks whose job it is to try to protect our troops and keep them from harm, here's one group that probably doesn't immediately come to mind: the scientists of the Agricultural Research Service (ARS).
Actually, the scientists of ARS have a long history of protecting the military, going back to the days just before World War II, when the Army asked the ARS scientists to come up with a more productive strain of penicillin so that sufficient quantities would be available to treat combat wounds. ARS-developed technologies have helped our armed forces fend off a whole array of pests, such as lice that spread typhus or the sand flies whose bites lead to the horrible wounds known to our troops in Iraq as "Baghdad boil."
Biopolished wool, developed at the ARS Eastern Regional Research Center in Wyndmoor, Pennsylvania, is displayed as an army neck gator. A new ARS-developed polymer can be added to this fabric to make it flame retardant. (Photo by ERRC)
Now those scientists have gone a step further and developed a way to make wool less susceptible to burning. That makes it an ideal fabric for uniforms worn not only by the military, but also by firefighters and others whose occupation exposes them to fire.
Wool burns with a self-extinguishing flame and turns into a soft ash. By contrast, some military garments currently are made of synthetic fabrics that, as they burn, melt into hard little beads that can drip into a wound and cause harm.
At the ARS lab in Pennsylvania, the scientists discovered and patented a heat-resistant material that can be incorporated into wool and other fabrics to give them as much flame resistance as that offered by commercial firefighters' uniforms. This technique was developed by the ARS scientists at the request of the U.S. military, one of the largest markets for domestic wool, to give our troops protection against fire-related injuries.
The ARS scientists improved the flame resistance of their biopolished wool by treating it with a heat-resistant polymer that's stable, easy to process, and highly tolerant of extreme temperatures. Unlike some popular flame retardants, the ARS material doesn't use the heavy metal zirconium, which can cause health hazards during processing. The polymer can also be used to treat natural, synthetic and blended fibers, but wool is particularly suitable because of its natural fire resistance.
Prepare to be impressed: Preliminary tests have shown that the burning behavior of ARS' polymer-treated wool is comparable to that of a 50/50 blend of wool and Nomex, the fabric that's currently used in protective firefighting gear.
Now the ARS scientists are experimenting with different methods to enhance the wool's heat-resistant and flame-retardant properties. Also, they say the flame-retardant treatment should stand up well to repeated laundering.
The ARS scientists' earlier accomplishments with biopolishing of wool have found eager customers. So far, nine companies have expressed interest in obtaining a license to use this patented technology, and the ARS Office of Technology Transfer has already issued two licenses for it.
The biopolishing removes the wool fiber's spiky tips, so the wool feels less scratchy. Also, the scientists use bleach to dissolve a protective fat layer wrapped around the wool fiber, leaving behind a lighter-colored fiber that's more receptive to dye.
That's why the biopolished wool could lead to longer-lasting garments. Typically, high temperatures are needed to dye wool — to get past that fat layer — and those high temperatures can weaken the fiber. With the fat layer out of the way, the wool can be dyed at cooler temperatures.
The biopolishing also includes an enzyme treatment that makes the wool machine-washable. The surface of a wool fiber is covered with a multitude of tiny scales, similar to fish scales, and when standard wool is washed, the heat and pressure cause those scales to tightly lock together. But the enzyme treatment breaks down those scales so they can't lock up. Normally that layer of fat that I mentioned earlier would protect the scales against the action of the enzymes, but the bleaching step eliminates that fat layer.
So there you have it: wool that's truly washable, silky-smooth, easy to color, and flame-resistant!
The Agricultural Research Service is the chief in-house scientific
research agency of the U.S. Department of Agriculture. You can read
more about ARS discoveries at http://www.ars.usda.gov/news/.
About the author
"Everybody's
Science" is written by Sandy Miller Hays, Director of Information for
the Agricultural Research Service, the chief scientific research agency
of the U.S. Department of Agriculture. Hays is a native of Fort Smith,
Ark. From the late 1970s until early 1988, Hays was a reporter, editor
and columnist at the Arkansas Democrat (now the Arkansas Democrat-Gazette),
a Little Rock-based daily newspaper. She joined the ARS Information
Staff in 1988, and became Director of Information in April 1998.