Investigation on of mordant usage in reactive dyeing of nylon fabrics

Nylon fiber is the most widely used fiber among synthetic fibers. Reactive dyestuffs are widely used in dyeing cellulosic products. Its most important feature is its ability to form covalent bonds with fiber. Natural and chemical mordants are substances that allow the dyestuff to adhere to the fiber. In this study, dyeing and coloring properties have been studied by using mordants on 100% nylon fabric and dyeing with reactive dyestuffs. Nylon fabrics were dyed in the presence of selected mordants by using blue reactive dyestuffs with Monochlorotriazine (MCT), Trifluoropyrimidine (TFP) and Monochlortriazine-Vinylsulfon (MCT+VS) functional groups. Iron (II) Sulphate, Potassium Aluminum Sulphate in the form of commercial metallic salt, and Tannic Acid as biomordant were chosen as mordants. Pre-mordanting, meta mordanting and post-mordanting were used as mordanting methods. pH 2, pH 4 and pH 6 were chosen for the pH conditions of dyeing. In dyeings using three different methods, reactive dyestuffs and pH range, transmittance measurements were made from the solutions taken before and after dyeing. Color differences (ΔE*) of nylon fabrics obtained by three different methods compared to fabrics dyed without mordant were measured. Washing, rubbing, acid, alkali, water and light fastnesses, dyestuff extraction was performed from dyed fabrics in the presence of pyridine solution. The results obtained were compared with nylon fabrics dyed without mordant. Percentage of dye bath exhaustion (%E), percentage fixation of the dye which exhausted (%F) and overall percentage fixation (%T) were determined. When the applied dyeing conditions, reactive dyestuff concentrations and mordanting methods were examined, it was found that metallic salt mordants gave better dyeing and colour fastness results at pH 2 and pH 4, especially in pre- and meta mordanting methods, compared to those of Tannic Acid. It was concluded that the usage of mordants in dyeing nylon fabrics with reactive dyestuffs improves the coloring properties.