Nomex is a trademarked term for an inherently flame-resistant fabric with meta-aramid chemistry widely used for industrial applications and fire protection equipment. It was developed in the early 1960s by DuPont and first marketed in 1967.[1]
Kevlar is often added to Nomex to increase its resistance to breakage or tear.
Properties
Nomex and related aramid polymers are related to nylon, but have aromatic backbones, and hence are more rigid and more durable. Nomex is an example of a meta variant of the aramids (Kevlar is a para aramid). Unlike Kevlar, Nomex strands cannot align during filament polymerization and have less strength: its ultimate tensile strength is 340 MPa.[2] However, it has excellent thermal, chemical, and radiation resistance for a polymer material. It can withstand temperatures of up to 370 C.[3]
Production
Nomex is produced by condensation reaction from the monomers m-phenylenediamine and isophthaloyl chloride.[1]
It is sold in both fiber and sheet forms and is used as a fabric where resistance from heat and flame is required. Nomex sheet is actually a calendered paper and made in a similar fashion. Nomex Type 410 paper was the first Nomex paper developed and one of the higher volume grades made, mostly for electrical insulation purposes.
Wilfred Sweeny (1926–2011), the DuPont scientist responsible for discoveries leading to Nomex, earned a DuPont Lavoisier Medal[4] in 2002 partly for this work.
Applications
Nomex Paper is used in electrical laminates such as circuit boards and transformer cores as well as fireproof honeycomb structures where it is saturated with a phenolic resin. Honeycomb structures such as these, as well as mylar-Nomex laminates, are used extensively in aircraft construction. Firefighting, military aviation, and vehicle racing industries use Nomex to create clothing and equipment that can withstand intense heat.
A Nomex hood is a common piece of racing and firefighting equipment. It is placed on the head on top of a firefighter's face mask. The hood protects the portions of the head not covered by the helmet and face mask from the intense heat of the fire.
Wildland firefighters wear Nomex shirts and trousers as part of their personal protective equipment during wildfire suppression activities. Racing car drivers wear driving suits constructed of Nomex and or other fire retardant materials, along with Nomex gloves, long underwear, balaclavas, socks, helmet lining and shoes, to protect them in the event of a fire.
Military pilots and aircrew wear flight suits made of over 92 percent Nomex to protect them from cockpit fires (previously issued flight suits were treated in borax solution prior to the introduction). It is also worn as sailors' anti-flash gear
History
The deaths in fiery crashes of race car drivers Fireball Roberts at Charlotte, and Eddie Sachs and Dave MacDonald at Indianapolis in 1964, led to the use of flame-resistant fabrics such as Nomex.[11] In early 1966 Competition Press and Autoweek reported: "During the past season, experimental driving suits were worn by Walt Hansgen, Masten Gregory, Marvin Panch and Group 44's Bob Tullius; these four representing a fairly good cross section in the sport. The goal was to get use-test information on the comfort and laundering characteristics of Nomex. The Chrysler-Plymouth team at the recent Motor Trend 500 at Riverside also wore these suits."[12]
See also
External links
- DuPont Nomex
- Dupont.com - 40th anniversary of Nomex - 2007
- Comparison of single-layer Nomex suits
References
- Hiroshi Mera, Tadahiko Takata. Ullmann's Encyclopedia of Industrial Chemistry 2000^
- DuPont™ Nomex® N301 Nomex® Aramid Staple Fiber^
- Tasneem Sabir. High-Performance Apparel 2018^