Shafat Ahmad Khan

Eco-dyeing of wool using aqueous extract of the roots of Indian madder (Rubia cordifolia) as natural dye

The aqueous extract obtained from the powdered roots of Indian madder (Rubia cordifolia) was used for dyeing of woolen yarns. The effect of pH, dye concentration, and mordants on the colorimetric and fastness properties has been studied. Brilliant shades of bright red to scarlet were obtained with significant variation in hue and tone of shades depending on mordants and dye concentrations used. The color coordinates of the dyed samples were found to be in the red-yellow quadrant of the CIELab color space. It was found in all cases that mordanting with alum as well as ferrous sulfate has caused decrease in lightness (L*) values and increase in K/S values. All the dyed samples exhibited commercially acceptable fastness to light, washing, and rubbing. Scanning Electron Microscopy (SEM) morphological studies have also been performed on different woolen yarns.

Mixed Metal Mordant Dyeing of Wool using Root Extract of Rheum emodi (Indian Rhubarb/Dolu)

In the present study, the root extract of Rheum emodi (Indian Rhubarb/Dolu/Revandchini) has been used as a natural dye to develop a variety of harmonizing natural shades on woolen yarn using combination of ecofriendly mixed metal mordants. Dyeings were carried out in neutral acidic, and alkaline medium using 0.5%–5% dye concentrations pre-treated with (4.5% iron + 0.1% tin), (2.5% iron + 0.5% tin), and (0.5% iron + 0.9% tin) mordant combinations. A total of 54 shades have been developed by varying the amount of dye and percentage combination of mordants. The hue of color ranged from reddish-brown, greenish-yellow to dark yellow. The color of dyed woolen yarns was investigated in terms of color strength (K/S), CIELab, CIELch values. Fastness properties (light, washing, and rub/crocking) of dyed woolen yarn samples were also assessed.

Developing a Shade Range on Wool by Madder (Rubia cordifolia) Root Extract with Gallnut (Quercus infectoria) as Biomordant

ABSTRACT Environmental issues inspire the revival of natural dyes that exhibit better biodegradability and more compatibility over synthetic ones. This research is aimed to investigate the effect of color and fastness properties on wool yarn substrate with natural anthraquinone colorants extracted from madder roots using gallnut (Quercus infectoria) extract as anchoring agent. Prior to the dyeing with Indian Madder (Rubia cordifolia), wool fibers were pre and post-treated with different concentrations of gallnut extract (viz 1–5% o.w.f) to get a broad range of beautiful and color fast shades. The feasibility of gallnut extract as an anchoring agent and its effect on color strength and color fastness to light, rubbing, and washing was investigated. Results of color characteristics showed that the color coordinates of the dyed samples were situated in the red-yellow quadrant of the CIELabcolor space. Bio-mordanting with gallnut extract produced shades of practically acceptable color depth, color fastness to light, washing and rubbing. Pre-treatment with gallnut extract is dominated over post-treatment in terms of better colorimetric and fastness results.