How new, lighter fabrics promote heat loss without sacrificing safety
New technology makes it possible to reduce the overall weight of turnout gear – and the stress on the firefighter wearing it – without compromising heat resistance
Sponsored by TenCate Protective Fabrics
By Randall D. Larson for FireRescue1 BrandFocus
With all the equipment firefighters need to carry to do their jobs, they can be wearing as much as 60 pounds of gear. All of this weight, along with the restricted movement caused by thick, heavy turnout gear, can increase exhaustion and make the job more demanding.
TenCate Protective Fabrics is working to ease that burden and support firefighter wellness by developing lighter weight fabrics for firefighting PPE.
“The lighter you can make the garment, the better it is for firefighters. It reduces stress,” said Greg Neff, emergency response market manager for TenCate Protective Fabrics. “Although a lot of things are playing into firefighter deaths today, the No. 1 thing you can do is reduce the amount of stress on that firefighter, and making the garment lighter reduces a ton of stress.”
MOBILITY AS A JOB AID
Mobility is essential for firefighters. Stiff clothing reduces flexibility, and for many years fire service turnout gear was extremely stiff. That stiffness was due largely to these garments being made with ripstop weaves – fabric made of nylon with a special reinforcing technique that made them resistant to ripping and tearing. That feature, however, also made them heavy and fairly inflexible.
But modern techniques are making firefighter PPE more movement-friendly. Today’s turnout gear is made with twill-based weaves that lighten the fabric significantly.
TenCate Protective Fabrics has developed a new fabric that weighs just 5.6 ounces per square yard, compared to older products still in the market that weigh closer to 7.5 ounces. That lighter weight makes it more maneuverable for the wearer to accomplish a critical job with considerably less stress.
“The older, heavier garments are not nearly as flexible as you would find with a lighter weight garment,” said Neff. “To go from a 7.5-ounce to a 5.6-ounce material is a huge difference, and just that in itself gives it more flexibility.”
TOTAL HEAT LOSS AND THERMAL PROTECTIVE PERFORMANCE
Lighter fabric also reduces heat stress, a serious hazard on the fireground that can also cause heart attacks and other serious health problems.
Lighter fabric is more breathable and provides increased heat loss to reduce the risk of heat stress. Denser materials hold more heat, so the lighter material promotes heat loss/protects the firefighter by letting more body heat and vapor escape.
NFPA 1971 establishes total heat loss and thermal protective performance standards for firefighting gear. The minimum requirement for total heat loss is 205 watts per square meter. But turnout gear includes three layers of material – an outer shell, a thermal liner and a moisture barrier – and those layered components can reduce the garment’s total heat loss. By reducing the weight of that fabric while preserving its protective capabilities, the garment will provide increased breathability and a higher THL.
NFPA 1971 also requires PPE to protect the wearer for a minimum of 17.5 seconds against heat penetrating the three layers and causing a burn. A lighter weight that promotes breathability and a higher THL must also generate the level of thermal protective performance needed to meet this standard.
TECHNOLOGICAL IMPROVEMENTS REDUCE WEIGHT, MAINTAIN PROTECTION
TenCate Protective Fabrics has been examining a number of fibers that can reduce the weight of firefighting PPE while maintaining the strength and heat resistance of these garments.
PBI Peak 5 is a 5.6-ounce material containing polybenzimidazole, a heat-resistant polymer fiber introduced to the fire service in the 1980s that is used to create outer shells.
“PBI Peak 5 has the most PBI in the market today in an outer shell,” said Neff. “It always has to be blended, and it’s typically always blended with Kevlar, whether it be a spun Kevlar or a Kevlar filament fiber. They blend those to give it the strength and the thermal protection that you need for fire service turnout gear.”
He also says PBI Peak 5 is the first fabric under 6 ounces available to the fire service. (As noted earlier, most protective fabrics weigh closer to 7.5 ounces, roughly 25% more than PBI Peak 5.)
Agility Tactical is a lightweight fabric made into technical rescue apparel for the urban search & rescue market. (It is not meant for structural firefighting garments.) This 5-ounce, twill-based weave blends three different fibers: PBO (polybenzobisoxazole, introduced to the fire service in the 1990s), Nomex and Kevlar.
This triple weave yields a lighter fabric for garments designed to meet NFPA standards for USAR, wildland firefighting and EMS use. This is why TenCate Protective Fabrics refers to the Agility Tactical fabric as a tri-certified material – because it meets the criteria for NFPA 1951, 1977 and 1999 and serves three different branches of fire and emergency response.
Both PBI Peak 5 and Agility Tactical are made stronger and lighter by a method TenCate Protective Fabrics calls ENFORCE Technology, which is an engineering of the fibers to make it a stronger product. This also helps increase abrasion resistance to extend the life of the garments.
“Instead of weaving two different fibers together, ENFORCE Technology combines the properties of both fibers into a single yarn,” said Neff. “It’s got great strength, great resistance and great weight – substantially lower than most things in the market. It’s very lightweight and very flexible. The means of movement is significantly better with this lighter weight product.”
TenCate Protective Fabrics continues to work toward a lighter product for protective garments to help increase mobility and reduce the physical load and overall stress on the firefighter.
“They can come out of a working situation, get rehabbed and head to their company or back to the family every night, safe and sound and healthy,” Neff said. “That’s why we’re trying to make lighter weight garments – just to reduce that stress on that firefighter, give him or her more mobility and allow firefighters to have the ability to do their job a little bit more successfully.”
Visit TenCate Protective Fabrics for more information.
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