Effect of Dyeing Conditions on Color and UV Protection of Wool Dyed with Beetroot Peel and Mordants

Abstract

The aim of this study was to investigate the potential of beetroot peel extract as a natural dye for wool, considering its color properties and UV protection characteristics. Wool fabrics were dyed with beetroot peel extract by pre-mordanting with aluminum and iron salts, and various dyeing parameters, such as pH and temperature, were investigated to optimize the dyeing conditions. Color measurements and fastness tests were conducted to assess dyeing efficiency. UV transmittance analyses were also carried out to evaluate the UV protection properties of the dyed samples. The highest color strength (K/S) value of 2.15 was achieved at 40 °C and pH 2 without the use of mordants, where deprotonated betalains produced red hues. Mordanting with FeSO₄·7H₂O resulted in the darkest shades and improved color stability. UPF values increased significantly after dyeing, with a maximum UPF of 1250 observed at 100 °C with FeSO₄·7H₂O. Wash and rubbing fastness ratings ranged from 3 to 4–5, indicating good overall durability. These findings demonstrate that beetroot peel can serve as a sustainable dye source with added functional benefits, such as UV protection, for textile applications.