By Alan M. Petrillo
Structural firefighting personal protective equipment (PPE) has three layers of protection: an outer shell, a moisture barrier, and a thermal liner. Each of those layers uses a different type of fabric to provide the firefighter with a safe envelope in which to work.
Fibers
Bryan Bolden, senior sales and marketing manager for PBI Performance Products, says his company makes fibers that go into the fabrics that are crafted into the various turnout gear layers. "The principle behind the PBI fiber is that it is more flexible, allowing a firefighter to do the job more efficiently and putting less stress on firefighters because of their turnout gear," Bolden says. PBI's latest innovation is the PBI Lightweight Gold system, says Brian Shiels, PBI's senior development engineer. The system uses either PBI Matrix or PBI Max fabrics made by Safety Components or Kombat Flex made by TenCate Protective Fabrics as the outer shell, a Stedair Gold moisture barrier, and a thermal liner of Glide with PBI G2 or TenCate's Quantum4. "The system is about a pound lighter for all the fabrics, but it's more flexible, so there is more perceived comfort for the wearer," he says. "It's also easier to don and doff the gear."
DuPont Protection Technologies makes two fibers often found in turnout outer shells-Nomex® and Kevlar®. Nomex fiber offers inherent flame resistance while contributing toughness and flexibility to outer shell fabrics, says Dennis Mater, DuPont Nomex sales technical leader for apparel in North America. "Nomex fiber thickens and carbonizes when exposed to intense heat from flames," he says. "This action increases the protective barrier between the wearer and the heat source, helping to reduce burn injury and providing valuable time to work or escape."
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1 Globe Manufacturing makes use of twill weave and both spun and filament yarns in the fabrics it uses for structural firefighting turnout gear. (Photo courtesy of Globe Manufacturing Inc.) |
DuPont Kevlar is one of the toughest fibers available on the market, Mater maintains. "On an equal weight basis, Kevlar fiber is five times stronger than steel," Mater says. "Yet fabrics made with Kevlar fiber can be lightweight, comfortable, inherently flame-resistant, and thermally protective. Kevlar fiber contributes to the overall durability and strength of lightweight turnout gear outer shell fabrics, enhancing strength and protecting the moisture and thermal barriers inside."
Mater points out that while Nomex and Kevlar fibers are used extensively in the layers of firefighter turnout gear, 70 percent of turnout gear's thermal protection comes from the inner components made of Nomex and Kevlar fiber.
Fabrics
Safety Components makes PBI Max, its newest PBI outer shell fabric, according to Guy Lucas, director of marketing, where the technological design gives firefighters the best combination of break-open and thermal protection, the strongest outer shell fabric, comfort, and flexibility. The weight of PBI Max is seven ounces per square yard (osy).
Another Safety Components outer shell fabric made from PBI fiber is PBI Matrix that combines the heat and flame protection with a durable matrix of high-strength 400- or 600-dernier filaments to reduce wear and tear. This results in high-performance flame and break-open protection, increased abrasion resistance, and improved tear resistance, Lucas says.