| Abstract: | The general thermodynamic schemes for predicting the amount of dye on the fibre which have been used by other workers are outlined. A new approach is then developed for the complex system of vat dyes on cotton, and the affinities of 14 vat dyes are calculated. The theory is extended to mixtures, and the variables of temperature, amount of salt added, amount of dye added, and amount of reducing agent added required to give a known colour are predicted from the theory. Cotton thread was dyed under different predicted conditions and the resultant matched dyeings are good evidence of the validity of the theory. In addition, the effects of the main dyeing variables on the resultant colour are predicted from the theory. |
