Abstract: To increase the spectra range of natural dyes and make up for the lack of green spectrum in natural dyeing process, two kinds of vegetable dyes including indigo naturalis and turmeric were selected to complex dye tussah silk fabric. The effects of dyeing concentration, pH value, temperature and time of the vegetable dye on tussah silk were studied in this paper. Then the complex dyeing mechanism, antibacterial activity, leveleness and color fastness were discussed. The results indicated that a series green spectrum could be obtained, and the turmeric concentration had obvious effect on the dyeing depth of the silk. The optimum technology of dyeing green color on tussah silk fabric was then obtained by quadrature experiments analysis: the relative concentration of turmeric dyestuff is 30%, the dyeing temperature is 80℃, the dyeing pH value is 4 and the dyeing time is 60min. The rubbing fastness and washing fastness of the dyed tussah silk were all more than grade 3, and the antibacterial reduction against S. aureus and E. coli reached to 92.56% and 80.41%, respectively.

Key words: natural dyes, tussah silk, over dyeing, levelness, antibacterial property