Abstract:
Silk and wool fabrics were coloured employing aqueous tea extract in absence and presence of magnesium sulphate, aluminium sulphate and ferrous sulphate as the mordanting agents. Colour uptake for wool was found to be more than that for silk under all conditions studied. Colouring biochemical components of tea revealed highest affinity for both the protein fibres at pH 2 to 4 in presence and absence of such mordanting agents. Use of ferrous sulphate and aluminium sulphate produced significant improvement in colour uptake following a pre- or post mordanting methods. Coloured protein fibres in general produced a light-fastness rating of 5 on a scale of 1- 5 and a wash-fastness rating of 4 on a scale of 1-5. Ferrous sulphate and aluminium sulphate improved colour retention on washing and the fastness properties further. Coloured protein fibres became blackish, when ferrous sulphate was employed as mordanting agent.