Ecological dyeing of silk fabric with lac dye by using padding techniques

Abstract

This research focuses on silk fabrics exhibiting different colour values and fastness properties. The samples were prepared by dyeing with lac as a natural colourant. Two padding techniques were used in the process, namely, the pad-batch and pad-dry techniques, under different conditions. Aluminium potassium sulphate, ferrous sulphate, copper sulphate and stannous chloride were used as mordants. The effects of differing dye concentrations added to the silk fabrics using a pre- and post-mordant method were studied and recorded. The colour fastness to washing, light, rubbing, water and perspiration of the dyed samples was performed according to the present ISO standard. Silk fabric dyed without mordant showed a pink shade, while those samples mordanted with stannous chloride and aluminium potassium sulphate displayed noticeably brighter red coloured shades. With the additional use of copper sulphate, the colour shade produced was violet, while darker grey shades were obtained by adding ferrous sulphate mordant. The test results regarding fastness properties ranged from fair to very good, while wash fastness ranged from very poor to poor.

Keywords:

• natural dyes
• silk
• dyeing
• pad-batch
• pad-dry
• lac

Acknowledgements

This research was financially supported by The Thailand Research fund, Office of the Higher Education Commission, Thailand and Rajamangala University of Technology, Phra Nakorn. We also thank Mr. Sukit Suthvanich and Ms. Pichamon Sriwichai for their help in collecting data.