COLOUR AND DYEING OF COTTON WITH NATURAL DYES

V diplomskem delu smo raziskali možnosti barvanja bombažne tkanine z naravnimi rastlinskimi barvili, pridobljenimi iz kurkume, koprive in hrastovega lubja. Barvanje je potekalo po izčrpalnem postopku, ob dodatku različnih kovinskih soli (Fe, Al, Cu) ali brez njih, pri različnih pH vrednostih. Kovinske soli vplivajo na barvni ton in boljše vezanje barvila z vlaknom. Po barvanju smo vzorce oprali. Izvedli smo tudi spektrofotometrično vrednotenje barve na opranih in neopranih vzorcih. Pri barvanju s kurkumo smo dobili različne rumene in rjave tone, pri barvanju s koprivo manj izrazite sivkasto-rjave barvne tone in pri barvanju s hrastovim lubjem rjavo oranžna obarvanja. Pri barvanju s kurkumo smo glede na pričakovanja dosegali najboljše rezultate ob sočasni uporabi aluminijevega sulfata in brez uporabe kovinskih soli v kislem mediju. V primeru barvanja s koprivo so bila najboljša obarvanja ob sočasni uporabi bakrovih in železovih sulfatov v alkalnem mediju, v primeru barvanja s hrastovim lubjem pa ob sočasni uporabi bakrovega sulfata in brez uporabe kovinskih soli v kislem mediju.In the thesis we researched the possibility of dyeing of cotton fabrics with natural plant dyes derived from turmeric, nettle leaves and oak bark. Dyeing was conducted according to the exhaustion dyeing procedure by the application of various metallic salts (Fe, Al, Cu) or without salts addition, at different pH values. Metallic salts influence the colour hues and lead to better bonding between the dye and the fibre. After dyeing, some samples were washed with distilled water and dried, and some not. The spectrophotometric evaluation of colour of washed and unwashed samples were also carried-out. Various tones of yellow and brown were obtained when dyeing with turmeric, pale greyish-brown shades when dyeing with nettle, and orange-brown colouring when dyeing with oak bark. The best results, regarding the colour depth, were achieved using a combination of turmeric and aluminium sulphate as well as without the metallic salts in an acidic medium. In the case of dyeing with nettle the best colouring appeared by copper and iron sulphate in an alkaline medium. In the case of dyeing with oak bark, the same result was achieved in the concurrent use of copper sulphate and without the use of metallic salts in an acidic medium