# Nomex
**Nomex** is a DuPont registered trademark for a family of meta-aramid (aromatic polyamide) fibers and papers, chemically poly(meta-phenylenisophthalamide), that are inherently heat- and flame-resistant: the material does not melt and drip, does not support combustion in air, and merely chars on prolonged exposure to high temperatures.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) It is a widely used commercial meta-aramid, used principally for flame-resistant apparel, firefighter garments, and electrical insulation.[2](https://www.sciencedirect.com/topics/engineering/resistant-fiber)
| Key fact | Detail |
|---|---|
| Chemistry | Poly(meta-phenylenisophthalamide), made from meta-phenylenediamine and isophthaloyl chloride in an amide solvent; at least 85% of amide linkages attach directly to two aromatic rings[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) |
| History | Developed by DuPont in 1960 and marketed in 1967; commercial scale in paper and fiber form from 1967, spunlaced constructions from 1983[2](https://www.sciencedirect.com/topics/engineering/resistant-fiber) • [1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) |
| Thermal behavior | Glass transition around 270 °C; decomposition temperature reported as about 450 °C in one review and 400–430 °C in a property comparison; does not melt or drip[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC12389889/) • [4](https://textiletuts.com/aramid-kevlar-yarn-spinning/) |
| Mechanical profile | Density 1.38 g/cm³; tenacity 4–6 g/denier; tensile modulus 10–17 GPa; elongation at break 20–30%[4](https://textiletuts.com/aramid-kevlar-yarn-spinning/) |
| Flame resistance | Limiting oxygen index 28–30 for fiber; Nomex 410 paper LOI 27–32% at room temperature[4](https://textiletuts.com/aramid-kevlar-yarn-spinning/) • [5](https://www.dupont.ca/en/news/nomex-410.html) |
| Moisture regain | 4.5% for Nomex fiber per one review; 5% cited for meta-aramid fibers generally[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC12389889/) • [6](https://www.sciencedirect.com/topics/engineering/para-aramid-fibre) |
| Main uses | Firefighter and flash-fire/arc-flash protective apparel, electrical insulation paper, honeycomb strength members in aircraft, filtration[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) |
## Molecular structure and why it resists heat
Nomex belongs to the aramid class, defined as long-chain polyamides in which at least 85% of the amide linkages are attached directly to two aromatic rings.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) What distinguishes it from Kevlar is linkage position: in Nomex the phenylene rings connect through the meta (1,3) positions, while Kevlar's para-aramid chains connect through the para (1,4) positions.[4](https://textiletuts.com/aramid-kevlar-yarn-spinning/) The meta-oriented phenylene forms bends in the polymer chain, a kinked or "zigzag" configuration that disrupts tight molecular packing.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) • [3](https://pmc.ncbi.nlm.nih.gov/articles/PMC12389889/)
This structural difference sets the two fibers on different paths. The kinked meta-aramid chain is more flexible, giving Nomex textile-like qualities and higher elongation (20–30% at break versus 2–4% for Kevlar 49), but lower tenacity (4–6 versus 20–28 g/denier) and lower modulus (10–17 versus 70–130 GPa).[4](https://textiletuts.com/aramid-kevlar-yarn-spinning/) In exchange, the aromatic rings and conjugated amide bonds give the polymer backbone a high degree of heat resistance, and the fiber's flame resistance is inherent to the polymer chemistry rather than a surface treatment, unlike flame-retardant treated materials.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf)
## History
DuPont developed Nomex in 1960 and marketed it in 1967; other accepted meta-aramid brands include Conex by Teijin and Apyeil by Unitika.[2](https://www.sciencedirect.com/topics/engineering/resistant-fiber) A DuPont military-protection brochure states that Nomex was invented by DuPont in 1967, and a Textile World anniversary account says DuPont introduced Nomex in woven and non-woven forms in 1967; the 1960 date in the fiber reference refers to the development work that preceded marketing.[7](https://www.dupont.com/content/dam/dupont/amer/us/en/safety/public/documents/en/Nomex_Thermal_Protection_for_Military_and_Police.pdf) • [8](https://www.textileworld.com/textile-world/textile-news/2007/03/dupont-nomex-marks-40-years-of-safety-and-protection/)
The fiber grew out of fundamental R&D by Paul Morgan and [Stephanie Kwolek](https://www.edgepedia.org/stephanie-kwolek), and Wilfred Sweeny unveiled the discoveries leading to final development at the [DuPont Experimental Station](https://www.edgepedia.org/dupont-experimental-station) in [Wilmington, Delaware](https://www.edgepedia.org/wilmington-delaware), finding a way to make a high-molecular-weight product that could be spun into a tough fiber.[8](https://www.textileworld.com/textile-world/textile-news/2007/03/dupont-nomex-marks-40-years-of-safety-and-protection/) Nomex reached the market in 1967, when DuPont began selling it commercially as both a paper and a fiber; spunlaced versions were added in 1983.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf)
## Forms and products
The Nomex family consists of staple fibers, continuous filament yarns, paper, and spunlaced fabrics.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) Nomex is sometimes blended with a small amount of Kevlar fiber.[9](https://www.sciencedirect.com/topics/physics-and-astronomy/aramid-fiber)
**Blends for protective clothing.** Because Nomex fibers shrink or break under very intense temperatures, DuPont developed a blend of 95% Nomex and 5% Kevlar marketed as Nomex-III, which is highly fire-resistant.[2](https://www.sciencedirect.com/topics/engineering/resistant-fiber) The later Nomex IIIA fabric combines 93% meta-aramid, 5% para-aramid, and 2% anti-static fiber, and is used as the outer layer of firefighter protective clothing.[10](https://pmc.ncbi.nlm.nih.gov/articles/PMC7475976/)
**Nomex 410 paper.** Nomex 410, the original form of Nomex paper, is a calendered insulation paper used in a wide range of electrical sheet insulation applications, available in thicknesses from 0.05 mm to 0.76 mm (2 to 30 mil).[11](https://www.dupont.com/content/dam/aramids/amer/us/en/safety/public/documents/en/Nomex_410_Tech_Data_Sheet.pdf) Arrhenius plots of aging behavior underlie its recognition as a 220 °C insulation by Underwriters Laboratories and other certifying bodies, and measurements show Nomex 410 maintains 12 kV/mm (300 V/mil) dielectric strength for several hours at 400 °C.[5](https://www.dupont.ca/en/news/nomex-410.html) The paper also performs well in cryogenic service: at the boiling point of liquid nitrogen (77 K), the tensile strength of 0.25 mm Nomex 410 exceeds its room-temperature value by 30% to 60% depending on direction.[5](https://www.dupont.ca/en/news/nomex-410.html)
## Applications
Staple, yarn, and spunlaced products serve as apparel fabrics protecting against flash fire and electric arc exposure, firefighter garments, filtration fabrics, insulation in flame-resistant thermal protective apparel, rubber reinforcement, and transportation textiles such as aircraft carpeting.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) Paper products serve as insulation in electric motors and transformers, wire wrapping, and honeycombed strength members in many aircraft.[1](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf) In aerospace, meta-aramids such as Nomex are used predominantly in non-structural applications where heat and fire resistance are paramount, while structural load-bearing roles go to para-aramids.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC12389889/) [Nomex honeycomb](https://www.edgepedia.org/nomex-honeycomb) is also sold as a core material for composite sandwich structures.[12](https://media.easycomposites.eu/datasheets/EC-SDS-Nomex.pdf)
Fabrics woven from Nomex fiber offer good textile properties, dimensional stability, resistance to many chemicals, and high resistance to most hydrocarbons and many other organic solvents.[13](https://revistaindustriatextila.ro/images/2024/6/Revista%20Industria%20Textila%206-2024%20web.pdf) Nomex paper exhibits good chemical resistance to most common acids and alkalis, fluorocarbon refrigerants, [transformer oil](https://www.edgepedia.org/transformer-oil), and silicones.[14](https://www.sciencedirect.com/topics/engineering/nomex)
## Nomex compared with Kevlar
The two DuPont aramids are chemically similar but not interchangeable. Para-aramids such as Kevlar deliver extreme tensile strength and modulus because their polymer chains align in rigid, linear configurations; meta-aramids such as Nomex trade mechanical performance for superior thermal stability and flame resistance.[15](https://www.aramidmaterial.com/para-vs-meta-aramid/) Meta-aramid fibers have a tensile strength of about 0.5 N/tex, comparable to high-strength nylon and polyester, and can withstand tensile stress, abrasion, and chemical exposure during flame contact at temperatures up to 400 °C.[6](https://www.sciencedirect.com/topics/engineering/para-aramid-fibre) Continuous service temperatures are 200–220 °C for Nomex 410 versus 180–200 °C for Kevlar 49, while decomposition temperatures favor the para-aramid (500–570 °C versus 400–430 °C).[4](https://textiletuts.com/aramid-kevlar-yarn-spinning/) Both fibers share a chemically inert surface, limited axial stretchability, low shear modulus, and UV degradation as drawbacks.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC12389889/)
## References
1. [Nomex® Fiber Technical Guide, DuPont](https://www.dupont.com/content/dam/dupont/amer/us/en/personal-protection/public/documents/en/Nomex%28R%29%20Fiber%20Technical%20Guide.pdf)
2. [Resistant Fiber, ScienceDirect Topics](https://www.sciencedirect.com/topics/engineering/resistant-fiber)
3. [Aramid Fiber-Reinforced Plastics (AFRPs) in Aerospace: A Review, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC12389889/)
4. [Aramid (Kevlar) Yarn Spinning: From PPTA Chemistry To End Uses, TextileTuts](https://textiletuts.com/aramid-kevlar-yarn-spinning/)
5. [Properties of Nomex® 410, DuPont Canada](https://www.dupont.ca/en/news/nomex-410.html)
6. [Para-Aramid Fibre, ScienceDirect Topics](https://www.sciencedirect.com/topics/engineering/para-aramid-fibre)
7. [Nomex® Thermal Protection for Military and Police, DuPont](https://www.dupont.com/content/dam/dupont/amer/us/en/safety/public/documents/en/Nomex_Thermal_Protection_for_Military_and_Police.pdf)
8. [DuPont™ Nomex® Marks 40 Years Of Safety And Protection, Textile World (2007)](https://www.textileworld.com/textile-world/textile-news/2007/03/dupont-nomex-marks-40-years-of-safety-and-protection/)
9. [Aramid Fiber, ScienceDirect Topics](https://www.sciencedirect.com/topics/physics-and-astronomy/aramid-fiber)
10. [Thermal-Protective Performance of Fire-Retardant Fabrics, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC7475976/)
11. [Nomex® 410 Technical Data Sheet, DuPont](https://www.dupont.com/content/dam/aramids/amer/us/en/safety/public/documents/en/Nomex_410_Tech_Data_Sheet.pdf)
12. [Nomex Honeycomb Safety Data Sheet, Easy Composites](https://media.easycomposites.eu/datasheets/EC-SDS-Nomex.pdf)
13. [Revista Industria Textila 6-2024](https://revistaindustriatextila.ro/images/2024/6/Revista%20Industria%20Textila%206-2024%20web.pdf)
14. [Nomex, ScienceDirect Topics](https://www.sciencedirect.com/topics/engineering/nomex)
15. [Para-Aramid vs Meta-Aramid: Key Differences, Impact Aramid Materials](https://www.aramidmaterial.com/para-vs-meta-aramid/)
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*Topic: Encyclopedia › Physical world and mathematics › Chemistry › Organic substances › Organic reactions, structure and reference › Organic polymer classes › Step-growth polymer classes › Polyamides and aramids*
*Initially written Sep 17, 2026 · Reviewed: Oct 15, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license