Improving light fastness of Reseda Luteola natural dyed wool with antioxidants and UV absorbent

One of the problems of natural yellow dyes (weld) is their low stability against light and their high fading rate. One of the main destructive factors in pale of color fibers and hand-woven carpet is the high-energy ultraviolet radiation which causes chemical bonds to break and optically damages of organic structures. In this study, the effect of some antioxidants (gallic acid, ascorbic acid) and conventional UV absorbents, (2- hydroxy benzophenone as a supplement agent is studied in order to improve light fastness property. The effect of light fastness variables such as exposure time, antioxidants concentration, relative humidity were optimized. Afterward, the obtained changes were compared with the original sample and were stated in terms of ΔE color change value. The results showed that in all cases, the use of UV absorbents or antioxidants relatively improves light stability properties of the samples. The best result in increasing light stability was observed in using gallic acid.