The present study reports on the leaching of natural pigment from Mucuna pruriens for dyeing of chrome tanned leather samples. The experiments were performed at temperature (30-70°C), time (30-90 min), feed to solvent ratio (1:3-1:7) and particle size (0.25-0.75 mm) using ethanol as solvent. The influence of process variables on percentage yield has been studied and the conditions were optimized using Box-Behnken design. The optimized conditions for intensified extraction was found to occur at a temperature of 60°C, extraction time of 1 hr, for a feed to solvent ratio of 1:5 and 0.75 mm particle size. The % yield under optimized conditions was found to be 47%. The extraction results were found to agree well with the statistical model (R2 = 0.9740). The colouring ability of extracted dye has been tested on wet blue goat leathers. The dyed leather exhibited a better colour value, strength and fastness properties as inferred from reflectance and visual assessment tests.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
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