Chromating of Wool Fibers Dyed with Madder Colorants, Luteolin Colorant and Iron Surface Treatment with a Residual Chromating Bath

摘要

The chromating of madder colorants (Rubia tinctorum ) and luteolin colorant from dyer’s weed (Reseda luteola) used in wool dyeing allows for a high degree of washing and rubbing fastness. The chromating process was optimized and verified by calculating the fixation rate of natural dyes and the reduced chrome. Chrome-dyes achieved a higher fixation rate than those without chromating dyes (61.8% versus 16.0% for madder colorants and 30.1% versus 11.0% for a luteolin colorant). The residual chromating bath was used to passivate the iron surface to avoid chrome rejection in the environment. The passivation was efficient, and the chrome was used almost completely on the metal surface. The chromating dyeing achieved a rigid fixation, as confirmed by washing-fastness test 105C6A01.