Metal Fiber
Metal fibers are drawn, bundled, or shaved from metals into filaments as fine as 1–100 μm — comparable to textile fibers in diameter but with entirely different physical properties. The dominant production method is bundle drawing: multiple metal wires are encased in a copper matrix, drawn together through progressively finer dies, then the copper is chemically dissolved, leaving behind thousands of ultra-fine individual metal filaments. The result is a fiber class that is electrically conductive, thermally conductive, cut-resistant, and capable of withstanding temperatures far beyond any organic fiber. But metal fibers are heavy (3–8× the density of polyester) and stiff — they are almost always used as a minority blend component (1–10%) rather than as standalone textile yarns.
Inorganic / Conductive Metallic Fiber
Quick Facts
| Type | Inorganic; drawn, bundled, or shaved from metals: stainless steel (304, 316L), aluminum, copper, nickel, titanium, and alloys |
| Production | Bundle drawing (multiple metal wires drawn together in a copper matrix → matrix dissolved → fine metal filaments); melt spinning (rapid solidification); shaving from solid metal |
| Filament diameter | 1–100 μm (bundle-drawn as fine as 2 μm; comparable to textile fibers) |
| Density | Stainless steel ~7.9; aluminum ~2.7; titanium ~4.5 g/cm³ — metal fibers are heavy by textile standards |
| Key brands | Bekaert (Bekinox®), Nippon Seisen (Naslon®), IntraMicron |
Classification
| Metal type | Alloy / Grade | Key property | Primary textile use |
|---|---|---|---|
| Stainless steel | 304, 316L | Corrosion resistance, high strength, ~600°C continuous | Anti-static garments, EMI shielding, conductive yarns, cut-resistant gloves |
| Aluminum | Pure Al, Al-Mg alloys | Lightest metal fiber (2.7 g/cm³), good conductivity | Lightweight EMI shielding, thermal reflectors, decorative |
| Copper | Pure Cu | Highest electrical conductivity (only silver is better), antimicrobial | Conductive traces in e-textiles, antimicrobial touch surfaces |
| Nickel | Pure Ni, Ni-Cr alloys | High-temperature resistance (~1000°C), corrosion-resistant | High-temp filtration, battery electrode substrates, aerospace |
| Titanium | Pure Ti, Ti-6Al-4V | Highest strength-to-weight, biocompatible, corrosion-proof | Medical implants, aerospace, high-end sports equipment |
| Silver-coated | Ag on PA or PET filament | Best conductivity per cost; flexible, lightweight | E-textiles, smart gloves, medical electrodes, antimicrobial |
| Nickel-coated | Ni on carbon or polymer | Moderate conductivity, lower cost than silver, EMI shielding | EMI gaskets, conductive gaskets, static dissipation |
Properties
| Property | Rating | Engineering implication |
|---|---|---|
| Electrical conductivity | ★★★★★ | Metallic conduction (resistivity ~10⁻⁵–10⁻⁶ Ω·cm); orders of magnitude better than carbon-filled; the defining property |
| Thermal conductivity | ★★★★★ | Excellent; stainless steel ~15 W/m·K; copper ~400 W/m·K; used for thermal management textiles |
| Heat resistance | ★★★★★ | Stainless steel continuous to ~600°C; nickel alloys to ~1000°C; far above any organic fiber |
| Cut resistance | ★★★★★ | Metal fiber blended into gloves provides excellent cut protection; EN388 Level 3–5 achievable |
| Weight | ★★☆☆☆ | ~3–8× heavier than organic fibers; a significant limitation for apparel; used sparingly (1–10% blend ratio) |
| Hand feel | ★★☆☆☆ | Stiff, cold, metallic feel; must be blended with soft fibers for comfort; fine filaments (<8 μm) improve comfort |
Applications
| Application | Form | Key criteria |
|---|---|---|
| Anti-static / ESD garments | Stainless steel staple, 2–5% blend with polyester/cotton | Permanent static dissipation (not wash-dependent like chemical antistats); cleanroom, electronics |
| EMI shielding textiles | Stainless steel or nickel filament; woven grid or blended | Reflects electromagnetic radiation; military, medical, electronics packaging |
| Cut-resistant gloves | Stainless steel filament core; wrapped with polyester/nylon | Food processing, glass handling, metalworking; EN388 certified |
| Conductive yarns / smart textiles | Stainless steel or silver-coated filament | Power and signal transmission in e-textiles; heated garments; wearable electronics |
| Filtration | Stainless steel nonwoven fleece; sintered metal fiber web | High-temp, chemically aggressive filtration; polymer melt filtration; reusable and cleanable |
Summary
Metal fiber brings electrical and thermal conductivity, cut resistance, and high-temperature capability to textiles — properties no organic fiber can provide. Its weight and hand limitations mean it is almost always used in blends at low percentages. See the Textile Material framework.