Strength band
Kevlar 49 class: very high tenacity and modulus versus nylon
Darker cells mean a higher score for this topic on that metric.
Strength94
Heat resistance82
Fire performance80
Insulation36
Workability40
Circularity38
LessMore
Last reviewed Sources & creditsMedia creditsMethodology
Quick answers
Is Aramid non-combustible?
Declared reaction class in this atlas: inherently FR vs commodity PA. Assemblies still need resistance tests.
Does Aramid insulate?
Thermal mark 36/100 versus the atlas. Conductivity note: low radial; fibre anisotropic.
What is the density band?
~1.44 g/cm³
How is it made?
Origin story: DuPont 1965 Kwolek (United States).
Can it be recycled?
Circularity mark 38/100 — editorial, route-specific.
Typical melting or failure heat?
does not melt; decomposes ~500 °C
heat 82 · fire 80
Numbers below are bands used by working engineers, not live quotes. Tensile note: Kevlar 49 class: very high tenacity and modulus versus nylon.
Fire performance in this atlas is editorial. Real projects need the assembly report.
Mechanical
Stiffness
Modulus follows chemistry and orientation — not the marketing nickname.
Toughness
Crack growth, not peak stress, retires most real parts.
Fatigue / creep
Cyclic and time-dependent damage dominate certificates issued on static coupons.
Hardness / hand
Indentation, drape or compressive class — whichever the trade actually measures.
Thermal
Conductivity
low radial; fibre anisotropic — Aramid is not a substitute for a dedicated λ layer.
Service temperature
Melting / softening / decomposition band: does not melt; decomposes ~500 °C.
Expansion
Joints and clearances must follow the expansion class of Aramid, not of steel-by-habit.
Thermal mass
Density ~1.44 g/cm³ sets how fast a section changes temperature.
Ageing of λ
Foams, VIPs and moist batts drift; quote aged values.
Electrical
Conductor or dielectric
Aramid is generally a dielectric or semiconductor film, not building wire.
Static / EMI
Fillers and moisture change resistivity more than brochures admit.
Standards language
IACS, volume resistivity or dielectric strength — pick the quantity the job uses.
Fire
Reaction to fire
Typical declared class: inherently FR vs commodity PA. This is not a universal passport.
Resistance vs reaction
Euroclass is reaction. EI/R ratings are assemblies — boards, coats, cavities.
Melt-drip / char
Aramid tends to char or stay inorganic rather than melt-drip like commodity olefins.
Smoke / toxicity
CO, HCN, HF or fibres — the species depend on chemistry. Name the test (ISO 5659, EN 45545, NFPA 1971).
If a salesperson quotes a single “safety score”, ask which standard, which thickness, which year.
Keep exploring
More in Textiles
🌱
Cotton
Seed-hair cellulose that dressed the industrial revolution — still the comfort fibre of daily wear.
Overall 44 🐑Wool
Crimped keratin that traps still air — suiting, carpets and a quietly decent fire story among apparel fibres.
Overall 53 🦋Silk
A kilometre-class animal filament — luxury cloth, sutures and a template for bio-inspired fibres.
Overall 41 🎽Polyester
The dominant apparel polymer — bottle-grade PET spun into staple that dries fast and sheds microfibres.
Overall 49 🪢Nylon
Carothers’ polyamide — stockings, tyre cord, climbing rope and a melt-drip fire personality.
Overall 48