Silk Physical and Mechanical Properties
topic
Properties: tenacity 3.5-5.0 g/den (dry), 2.8-4.0 g/den (wet, 20% loss, better wet strength retention than cotton/wool), elongation at break 10-25%, elastic recovery 92% at 2% extension (excellent resilience, wrinkle resistant), moisture regain 11%, density 1.34 g/cm³, thermal conductivity 0.06 W/(m·K) (cool in summer, warm in winter), dielectric constant low (antistatic), UV resistance poor (degrades 50% strength after 200 hours direct sunlight), resistance to most acids (damaged by alkalis pH >10, dissolved in concentrated mineral acids), excellent drape (0.5-2 cm bending length), and characteristic luster (light refraction through triangular cross-section and molecular orientation).
Role
Silk's unique property combination—high strength with good elongation creating toughness (energy absorption 70-90 MJ/m³), moisture absorption providing comfort, natural luster and drape defining aesthetics, and protein structure enabling dyeing—position it as ultimate luxury natural fiber, though UV sensitivity and alkali weakness require care (no chlorine bleach, no direct sunlight storage).