Colour Intensity, Fastness and Antimicrobial Characteristics of Silk Fabric Dyed with Mahua Bark

摘要

A study was conducted to analyse the shades and colour fastness property of silk fabrics dyed with colour extracted from mahua bark at different concentrations of mordants. Four types of mordants, viz. CuSO4, Al2(SO4)3, alum and citric acid, were used for the study. The colours of the fabrics were quantified with the help of Hunterlab colour scale. For mahua bark dye, the maximum ?E* value (52.95?0.29) was observed for 3% CuSO4 mordant treated samples. However, the values were not significantly different from 2% and 1% CuSO4 treated samples. The change in chroma was maximum for the 3% Al2(SO4)3 mordant (34.89?0.33), though that offered by 1% and 2% Al2(SO4)3, and 1% and 3% CuSO4 were not significantly different from the above. The colour fastness property was measured in a scale of 1-5 (very poor, poor, fair, good and excellent). All the mordants except alum helped in maintaining good to excellent fastness to washing. The staining on undyed silk exhibited excellent colour fastness for all three mordants except CuSO4, which showed good to excellent colour fastness. The dry crocking and wet crocking fastness characteristics were also compared for all the treatments. The specimen dyed with alum, Al2(SO4)3 and citric acid exhibited moderate light fastness whereas specimen dyed with CuSO4 exhibited fairly good colour fastness. The samples without mordants showed poor fastness. The antimicrobial profile indicated that the mahua bark dye was not sensitive to the growth of E. coli, Streptococcus sp. and Salmonella as indicated by the poor zone of inhibition. However, it was sensitive to S. leuteus. Similarly, the fungal isolates, viz. Aspergillus nigricans and Candida albicans used for the study were resistant to the dye.