Targeted Mitigation of Non-Scourable Wool Discolouration

Abstract

Non-scourable canary yellow discolouration of fleece wool severely limits the utility and therefore value of affected wool lots. There is currently no commercial process available that specifically targets the reduction of this discoloration. Recently, phenazine-based chromophores have been identified as key contributors to this wool staining. Bleaching chemistries targeting phenazines were investigated and trialled for application as potential pre-whitening treatments for non-scourable discoloured wool. Reductive approaches utilising the industrially applicable reagents, sodium hydrogensulfite and disodium disulfite, showed promise in investigations into solubility and colour improvement. These reagents were subsequently used in the development and optimisation of treatments to improve the colour in canary yellow wool. Substantial improvements in whiteness were achieved without causing observable fibre damage. This result offers promise as a potential route to mitigate the effects of canary yellow discoloration on wool value.