Corona treatment in air and air/chlorine atmospheres, does alter the wool fiber so it appears visually significantly more yellow than the untreated wool. The yellowness of wool after corona treatment, particularly that done in the presence of chlorine, may be reduced to the yellowness associated with non-corona treated, unbleached wool by scouring or solvent treatment. The amount of material extractable from wool is not greatly increased by corona treatment, suggesting that corona treatment is restricted to the surface layer of keratin fibers.
