Last week we talked about Proban - a dense cotton fabric weave that is made flame retardant by chemical treatment. And although more inexpensive, the chemical will eventually wash out.

This week we talk about man-made fibers like NOMEX, KEVLAR, and CarbonX. NOMEX is DuPont's registered trademark for a material engineered to be fire retardant. Originally designed for parachutes for the space program, it is the most popular fire suit material. When flame comes in contact with NOMEX, the material simply chars and will not support combustion. The threads also increase in diameter and become thicker to provide a protective barrier between the heat source and the skin. Although it is more expensive, the fire retardant properties will never wash out. There are several catergories of NOMEX fire suits, some more durable and some more comfortable. This is mainly a product of how tightly the material is woven. A tight knit will be more durable, but is heavier and less breathable. Examples of this are the Simpson Gabardine NOMEX (tightly woven) and the sateen or diamond NOMEX (loosely woven). A suit made from the gabardine NOMEX will be stiffer and hotter, but is very durable. One made from the sateen or diamond NOMEX will be less durable but much looser fitting and cooler. Certain weaves also have more colors available than others. KEVLAR is another registered product by DuPont that is most well known for its strength. Also fire retardant, KEVLAR is normally used at seam and zipper locations. CarbonX is a fairly new material, but quickly gaining popularity. Produced by Chapman Thermal Products, CarbonX behaves like NOMEX when exposed to flame. However in laboratory tests, CarbonX does seem to outperform NOMEX in its ability to self-extinguish when exposed to direct flame and limit the oxygen present between the weaves by expansion. Currently more expensive than NOMEX, CarbonX is mostly used in fire retardant underwear applications, head socks, foot socks, and glove linings. Selection of colors in CarbonX is currently limited to black.

So in summary, a NOMEX suit will be more expensive than a PROBAN suit. But, it should last longer in that you will never wash the fire retardant properties out of materials like NOMEX, KEVLAR, or CarbonX.

Until next week - Be fast. Be Safe.
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Tim Currier
GauntletRacing.com
Racing Safety Gear
877-524-2491