Analytical Technique for Characterizing the Initial Stage of the Dyeing Process

A convenient experimental apparatus is developed for analyzing the initial stage of several seconds at the start of the dyeing process under rapid adsorption conditions. A cationic dyeable acrylic fiber is dyed at 90°C and pH 6.4 with 0.002% methylene blue solution at a 500:1 liquor ratio. The fiber is left in the 90°C steamed atmosphere for 30 minutes before dyeing. The wavelength of the 668 nm monochromatic light beam transmittance is detected with multiple optical glass fibers inserted directly in the dye bath. Six percent of the dye uptake in the fibers after 2 hours' dyeing is adsorbed before I second. In case of a cationic dyeable polyester fiber, 9% is adsorbed in the same period.