Nomex

Key takeaways

Nomex belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nomex to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nomex from memory before moving on to harder problems.

Reference excerpt

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.

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 (49,000 psi). However, it has excellent thermal, chemical, and radiation resistance for a polymer material. It can withstand temperatures of up to 370 °C (700 °F).

Production Nomex is produced by condensation reaction from the monomers m-phenylenediamine and isophthaloyl chloride. 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 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. Troops riding in ground vehicles often wear Nomex for fire protection. Kevlar thread is often used to hold the fabric together at seams. Military tank crews also typically use Nomex uniforms as protection against fire. In the U.S. space program, Nomex has been used for the Thermal Micrometeoroid Garment on the Extravehicular Mobility Unit (in conjunction with Kevlar and Gore-Tex) and ACES pressure suit, both for fire and extreme environment (water immersion to near vacuum) protection, and as thermal blankets on the payload bay doors, fuselage, and upper wing surfaces of the Space Shuttle Orbiter. It has also been used for the airbags for the Mars Pathfinder and Mars Exploration Rover missions , the Galileo atmospheric probe, the Cassini-Huygens Titan probe, as an external covering on the AERCam Sprint, and is planned to be incorporated into NASA's upcoming Crew Exploration Vehicle. Nomex has been used as an acoustic material in Troy, NY, at Rensselaer Polytechnic Institute's Experimental Media and Performing Arts Center (EMPAC) main concert hall. A ceiling canopy of Nomex reflects high and mid frequency sound, providing reverberation, while letting lower frequency sound partially pass through the canopy. According to RPI President Shirley Ann Jackson, EMPAC is the first venue in the world to use Nomex as an architectural material for acoustic reasons. Nomex (like Kevlar) is also used in the production of loudspeaker drivers. Honeycomb-structured Nomex paper is used as a spacer between layers of lead in the ATLAS Liquid Argon Calorimeter, and as a laminate core for hull and deck construction in custom boats such as Stiletto Catamarans like the Stiletto 27. Nomex is used in industrial applications as a filter in exhaust filtration systems, typically a baghouse, that deal with hot gas emissions found in asphalt plants, cement plants, steel smelting facilities, and non-ferrous metal production facilities. Nomex is used in some classical guitar tops in order to create a 'composite' soundboard. When Nomex is laminated between 2 spruce or cedar 'skins', a rigid and lightweight plate is produced, which can improve the efficiency of the soundboard. While the 'laminated' technique was created by Matthias Dammann, the use of Nomex within was first employed by luthier Gernot Wagner.

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. 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."

See also Aramid Gore-Tex Kevlar Marlan PET film Silica Aerogel Thermal Micrometeoroid Garment Twaron Vectran

References

External links DuPont Nomex Dupont.com Archived 2012-02-17 at the Wayback Machine - 40th anniversary of Nomex - 2007 Comparison of single-layer Nomex suits

Illustrations

Worked examples

Example 1 — a first encounter with Nomex

Start with the simplest possible case. Write down what Nomex claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nomex before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nomex ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nomex

In research: Nomex appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nomex in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nomex is common in secondary-school and first-year university syllabi. It links to neighbouring topics Brand name materials, DuPont products, Firefighting equipment, so understanding it makes those chapters shorter.
In everyday life: Look for Nomex outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Nomex in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nomex means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nomex out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nomex in simple terms?

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.

Why does Nomex matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nomex?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nomex.