UV reflectance attributed direct correlation to colour strength and absorbance of natural dyed yarn with respect to mordant use and their potential antimicrobial efficacy

In this study, an attempt has made to investigate the impact of UV reflectance of un-dyed and dyed cotton yarn on the quantity of natural dyes absorbed by the fibre and observed its colour intensity. The study also provides evidence of the relationship between the UV reflectance and the colour strength of the dyed cotton with respect to mordant. The absorption of dyes on cotton yarns ranged from 5.06 to 34.09% in 5% dye solution of different plant extracts. Experimental data revealed that the higher colour intensity (K/S) corresponded to lower UV-reflectance and higher dye absorption of the dyed yarns. It was demonstrated that the dyed cotton yarns displayed excellent antimicrobial activity against bacterial strain Streptococous pyogenes (reduction rate: 52-61%) and the fungal strain Aspergillus niger (reduction rate: 35-63%) for developing protective clothing. The current findings clearly demonstrate that the extraction of natural colourants from waste leaves and superficial barks of the plants could be a sustainable technology for waste utilization of bio-resources by the small-scale segments as well as the rural weaver's societies for their socio-economic growth. (C) 2015 Elsevier Ltd. All rights reserved.