Effect of Ultra Violet (UV) Irradiation as an Environmentally Friendly Pre-Treatment on Dyeing Characteristic and Colorimetric Analysis of Wool

Low-energy UV lamps were used for the pretreatment of wool yarns and its effects were investigated in terms of surface morphology, tensile strength, and percentage dye uptake. Subsequently, raw and UV-treated wool yarns were dyed with Cochineal dye and the essential parameters affecting the dyeing process (i.e., temperature, pH, duration) were determined. The results showed that the color strength of the samples increased by (a) increasing the pre-treatment effectiveness (i.e., UV irradiation strength and its duration), and (b) increasing the influential dyeing parameters (i.e., higher temperature, higher initial dye concentration in the dye bath, longer dyeing time, and acidic pH). The UV irradiation pretreatment also enhanced the color fastness properties of the dyed samples under the same dyeing conditions. The results suggested that an eco-friendly, acid-free, and relatively cheaper dyeing process could be developed for the wool fibers pretreated with scalable and straightforward UV irradiation pretreatment.