الفهرس | Only 14 pages are availabe for public view |
Abstract In this summary, we report the suggested plane for the preparations of three new fixing agents and we investigated their chemical composition by using Elemental analyses. As we know that the cotton fabric need many preparations for dyeing )scouring , bleaching…….etc) we make the first preparation is known as scouring this is very important step where the fabric get rid from the, oil ,fats ,waxes ,mineral ,leafy matter and impurities . these impurities are not soluble in water. so they obstruct the dyeing process. we use (soda ash . caustic soda and nonionic detergent) . The second preparation is textile bleaching by using hydrogen peroxide (2-7%) of the weight of fabric. The third preparation is optical whiteners to make the fabric more brilliant white (for white fabrics only). In dyeing process we dyed with direct dyes with many concentrations and different colors (blue 3%, 2%, 1%) and (red 3%, 2 %, 1%). The dying mechanism for the application of direct dyes to cotton fiber involve the absorption , diffusion and migration over fiber When the cellulosic fiber is immersed into water the amorphous regions of the fiber swell to produce small pores in the order of 20-100A units- the smaller size dye molecules diffuse into the fiber structure through these pores. The addition of electrolytes (e.g. Sodium chloride, sodium sulfate) assists the diffusion and exhaustion of direct dye anionic by neutralizing the negative surface charge of the cotton fabric. Then the dye |