O o d h e a d p u b L i s h I n g L i m I t e d

8
The coloration of wool
D.   M.   L E W I S, The University of Leeds, UK
Abstract: Wool coloration has to respond to real and perceived
environmental threats and this aspect tends to drive the selection of dyes and
dyeing processes. Reactive dyes bring benefits such as excellent wet-fastness
and some classes of reactive groups give excellent fibre protection,
especially when dyeing medium to deep shades. The fundamental chemical
principles behind the above important effects are described. The role of anti-
setting agents such as hydrogen peroxide or maleic acid in the dyebath is
described and explanations are given of their influence on the disruption of
cysteine thiol breakdown to hydrosulphide anion, which is the trigger for the
permanent setting observed following wool dyeing in boiling dye-baths. The
chapter concludes with a description of the great opportunities provided by
printing wool fabrics using ink-jet printing.
Key words: acid dyes, chrome dyes, reactive dyes, dyeing machine-
washable wool, anti-setting agents, ink-jet printing of wool.