Silk Degumming and Finishing
topic
Degumming methods: (1) soap-alkali method (traditional, 95-98°C water with 0.3-0.5% soap and 0.1-0.2% soda ash for 30-60 min, multiple baths removing 20-30% sericin weight), (2) enzyme degumming (proteases at 50-60°C pH 8-10, controlled selective sericin removal, better fiber integrity, 10-15% weight loss), (3) acid degumming (citric/tartaric acid, mild conditions preserving weighting agents). Post-degumming: washing, neutralizing, optional weighting (metallic salts—tin, silicates—adding weight compensating for sericin loss, 15-30% weight increase, improving body/drape but reducing durability), optical brightening, softening, and finishing (water repellent, crease resistant, antimicrobial treatments).
Role
Degumming transforms harsh, stiff raw silk into soft, lustrous fabric revealing silk's characteristic properties, with method selection balancing efficiency (soap-alkali fastest), fiber quality (enzyme gentlest), and economics (weighting reduces processing cost but controversial—disclosure required, affecting long-term durability reducing strength 30-50% over decades).