engleski

Cochineal colored cotton as UV shield: UV protective properties of cotton material dyed with cochineal dyestuff

According ecological lifestyle trends, natural dyes are experiencing their revitalization in the field of textile application. Many designers opt for a sustainable style and realize color palettes with natural dyes using traditional techniques and methods. However, in modern times, the use of natural dyes must be supported by scientific research due to care for human health and the environment, i.e. the choice of resources, conservation of natural habitats, ensuring the color fastness, selection and optimization of the use of mordant, etc. Textiles dyed with natural dyes have specifically beautiful and harmonious dye tones, and in the field of toxicology avoids the harmful effects of synthetic dyes. In addition, natural dyes have antibacterial, antimicrobial, antifungal properties, their beneficial effect on human skin and health in general, is examined. In this study, dyeing of cotton material with natural dye of animal origin extracted from the insect Dactylopius coccus was carried out. Metal salts potassium aluminum sulfate dodecahydrate, copper(II) sulphate pentahydrate and iron(II)sulfate heptahydrate were used in the pre-treatment process as mordants on cotton fabric in order to obtain coloration of specific purple hue. The influence of dye concentration, type and concentration of mordants on the obtained cotton color hues and their correlation with the UV protection property was investigated. Spectral color properties based on spectrophotometric measurement and are shown as the Kubelka-Munk coefficients (K/S) and CIEL*a*b* color values. The fabric UV protection was determined according to AS/NZS 4399:1996 Sun Protective Clothing: evaluation and classification, by UV-A and UV-B transmission measurement on transmission spectrophotometer and calculation of Ultraviolet protection factor (UPF). The obtained results prove that by dyeing textiles with cochineal dye with mordant pretreatment can significantly affect the protective properties of cotton material from UV radiation. Fabrics dyed with cochineal dye (without the addition of electrolytes and the use of mordant) have a UPF value ranging from 10 to 15. The addition of electrolytes increases the K/S values and the UPF value of fabrics increases to 20. A significant increase in UPF values is achieved by using mordants. For samples pre-treated with aluminum sulfate dodecahydrate UPF is 40, with copper (II) sulfate pentahydrate up to 35 and the highest values are achieved with iron(II) sulfate heptahydrate for i.e. UPF 50+. Research has shown that textile material dyed with cochineal dye provides good protection against harmful solar radiation, i.e. the material treated in this way has a higher UPF value (up to UPF 50+) compared to the untreated. Cochineal colored cotton offers protection against UVB radiation, and therefore it may reduce the risk of subsequent occurrence of skin cancer.

natural dyestuff, cochineal, UV protection, cotton

nije evidentirano