DuPont™ Nomex® Meta-Aramid Fiber
Nomex® is a meta-aramid, also known as Aramid 1313. It is characterized by good heat resistance and high strength; at a temperature of 250°C, the material’s properties can remain stable for a relatively long time. Its needle-punched products are mainly used as high-temperature filtration materials and insulation materials. It is an aromatic polyamide, commonly referred to as aramid. The molecular structure of this material is particularly stable, which gives Nomex® its outstanding performance. It has excellent high-temperature resistance, flame retardancy, non-toxicity, and relatively good electrical and mechanical properties.
Poly(m-phenylene isophthalamide), a synthetic fiber, Nomex® (meta-aramid or Aramid 1313), with the chemical name poly(m-phenylene isophthalamide). In laboratory heat resistance tests, it must withstand an open flame at a distance of 3 centimeters at 300 to 400°C; only if it does not ignite within 10 seconds can it be used to manufacture racing suits. The underwear, balaclavas, socks, and gloves of drivers and team personnel are all made from Nomex.
Performance Parameters
Insulation
Intrinsic dielectric strength, Nomex® treated with calendering can withstand a short-term electric field strength of 18 to 40 KV/mm without the need for further treatment with varnish or resin. Due to the product’s low dielectric constant, the electric field distribution between the insulation and the cooling medium is more uniform.
Mechanical Toughness
The Nomex® products have very high strength after calendering, and they exhibit good elasticity, tear resistance, and abrasion resistance. Thinner products are more flexible.
Thermal Stability
Nomex® products are recognized with a UL material temperature rating of 220°C, which means they can maintain effective performance for more than 10 years even when continuously exposed to 220°C.
Compatibility
Nomex® is generally unaffected by most solvents and is highly resistant to acid and alkali corrosion. It is also compatible with all varnishes, adhesives, transformer oils, lubricants, and refrigerants. Additionally, it is not damaged by insects, fungi, or mold.
Low Temperature Performance
At the boiling point of nitrogen (77K), the tensile strength of Nomex® T410 insulation paper and laminate exceeds the values at room temperature.
Moisture Insensitivity
When the relative humidity is 95%, Nomex® products maintain 90% of their dielectric strength compared to the fully dry state, and many mechanical properties are actually improved.
Radiation Resistance
Nomex® products are essentially unaffected even at ionizing radiation levels up to 800 megarads, and they retain their mechanical and electrical properties after eight such doses of radiation.
Non-Toxic/Flame Retardant
Nomex® products do not cause any known toxic reactions to humans or animals. The products do not melt or support combustion in air. At 220°C, their Limiting Oxygen Index (LOI) is greater than 20.8 (the general critical ignition value), so they do not ignite, and the products meet the flame retardant requirements of UL94V-0.
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| Dtex | Denier | Fracture strength (N) | Elongation at break (%) | Tensile modulus (CN/TEX) | Number of filaments (F) | Length (M/KG) |
|---|---|---|---|---|---|---|
| 1330 | 1200 | 234.93 | 3.4 | 5240 | 666 | 9000 |
| 1780 | 1600 | 343.80 | 3.42 | 5146 | 1000 | 6000 |
| 3300 | 3000 | 680.20 | 3.45 | 5120 | 2000 | 3000 |
Filter Media Application
Nomex® fibers have excellent high-temperature resistance, flame retardancy, good spinnability and dimensional stability, and relatively good mechanical properties. In industry, they are made into filter bags that can withstand flue gases at 200°C, with instantaneous temperatures reaching 250°C, and are widely used in dust removal projects for high-temperature flue gas at the kiln head and kiln tail of cement rotary kilns.
Flame-Retardant Fabric
Fabric made from Nomex® fibers, with the addition of 2% antistatic agent and 5% Aramid 1414, can be made into 3A flame-retardant fabric, which is an ideal choice for workwear in the petroleum industry.
