Assessment of knitted silk and cotton fabrics dyed with hibiscus rosa-sinensis (China rose plant) extract.

Abstract

The study investigated the effects of different methods of application of selected mordants on dyeing knitted cotton and silk fabric samples with the dye extract from the leaves of hibiscus rose-sinesnsis. The methods of application of mordants used included; pre-mordanting, simultaneous mordanting and post-mordanting. The effects on cotton and silk analysed were color fastness to; light, washing, wet and dry rubbing. Aqueous extraction method was used to extract the dye. Some selected mordants were used for dyeing viz; alum, ferrous sulphate and iron water. In the control dyeing without the use of mordants, very good fastness was registered with the following fastness ratings; for washing (4-5), dry rubbing (5), wet rubbing (5) and light (4). The natural dye is a substantive dye since it registered very good fastness grades without the use of mordants. The use of mordants improved color fastness to washing from ratings of (1-2) t0 (4-5) for cotton dyed fabric samples. Post-mordanting method registered the best overall fastness results.