Conclusion
A natural dye extracted from mangrove bark has been applied to silk fabric through exhaust dyeing. For the range of conditions used in the experiments, the optimum dyeing effect was achieved at a temperature of 90 ◦ C, 60 min dyeing time and pH of 3. Further improvement in color yield was observed with increasing dye concentration and additional mordanting. Each metallic salt mordant gave different color shades from medium to dark reddish-brown for aluminum potassium sulfate, stannous chloride, and copper sulfate to significantly duller and darker shades for ferrous sulfate. All mangrove bark dyed silk fabric exhibited fair to very good color fastness to crocking and fair to good light fastness with the exception of samples mordanted with stannous chloride, whose light fastness was very poor. The water and perspiration fastness ratings were good to very good, except for the fabric mordanted with ferrous sulfate, whose color change rating was poor to fair for perspiration fastness. However, the overall wash fastness was rated very poor to poor as a result of a change of color shade but there was no fading of the color after the washing test in the basic standard detergent solution.
Acknowledgements
This research was supported by Rajamangala University of Technology Phra Nakhon, Thailand.