Carbonization and Chemical Purification of Wool

Carbonization removes vegetable matter (VM) contamination from raw wool by impregnating fiber with 4–7% H₂SO₄, drying at 65–75°C, then baking at 100–110°C to char cellulosic impurities. Crushed and dusted residue is neutralized with Na₂CO₃ (2–3%) at 40–50°C, reducing VM content from 2–5% to below 0.5%. Process causes 3–8% fiber strength loss and must be carefully controlled to prevent over-carbonization. Neutralization and washing require 20–30 L water/kg wool. Carbonized wool commands premium pricing in worsted spinning where VM causes yarn defects and dye irregularities in suiting fabrics.