Silk fabric dyeing with natural dye from mangrove bark (Rhizophora apiculata Blume) extract

Abstract

Natural dye extracted from mangrove bark was applied to a silk fabric by an exhaustion dyeing process. Aluminum potassium sulfate, ferrous sulfate, copper sulfate, and stannous chloride were used as mordants. The dyeing was conducted with and without metallic salt mordants, using three different mordanting methods: pre-mordanting, meta-mordanting, and post-mordanting. The color of each dyed material was investigated in terms of the CIELAB (L*, a* and b*) and K/S values. The color fastness to washing, crocking, perspiration, and water of the dyed samples was determined according to AATCC test methods, whereas the color fastness to light was tested according to the ISO standard. Optimum results were achieved when dyeing at 90°C for 60min and at pH 3. Silk fabric dyed without mordant had a shade of reddish-brown, while those mordanted with stannous chloride, aluminum potassium sulfate, and copper sulfate produced a variety of pale to dark reddish-brown color shades. However, duller and darker shade was obtained with ferrous sulfate mordant. The color fastness to washing was mostly very poor to poor but there was no fading of the color, whereas the color fastness to light and crocking were mostly fair to good level. However, the perspiration and water fastness results showed good to very good levels, except for fabric mordanted with ferrous sulfate, whose color change rating was poor to fair for perspiration fastness. Tensile strength, tearing strength and stiffness of the fabrics before and after dyeing were also evaluated.