Influence Of Alkali And Temperature On Fixation And Color Coordinates In Dyeing With Different Reactive Dyes

Influence of alkali and temperature were studied on dyeing of cotton fabric with bi-functional Fluoro Chloro Pyrimidene (FCP), bi-functional Monochlorotriazine-Vinyl Sulphone (MCT-VS) and mono functional Monochlorotriazine (MCT) reactive dyes. For this analysis single joursey knitted fabrics were taken. The selected dyestuffs were Drimarene Yellow K-2R (FCP), Drimarene Red CI-5B (MCT-VS) and Drimarene Navy X-GN (MCT). 1% on the weight of fabric (owf) of each dye was considered for producing 15 single shades by varying the alkali amount and the temperature. Soda ash was used in each dye bath as alkali. As MCT dye is a lower reactive dye, Caustic soda was also added in its dye bath. The post dye liquors and post wash liquors were tested in absorbance spectrophotometer to measure the absorbance of those solutions. Beer-Lambert law was used to get concentration from absorbance and then the fixation% was calculated. The dyed fabric samples were tested in a reflectance spectrophotometer to get the color coordinates (L*, a*, b*, c*, h*). The results show that FCP dye fixation was the best among these three and MCT dye fixation was the least. Alkali increases the fixation of all dyes up to a level and temperature applied here has almost no influence on FCP dyes. MCT-VS dye has a tendency to changing its hue in different alkali amount and temperatures.