The chromatograms of reactive dyes are complete Bright color It is widely used in the dyeing of fiber fabrics. Reactive dyes such as alkali and salt are generally used in dyeing. It has a certain dye uptake, and even the fixed dyes will be hydrolyzed at the same time The hydrolyzed dye is adsorbed on the fiber to form floating color These floating color hydrolyzed dyes, dyes not bonded to the fiber and other auxiliary impurities must be removed by water washing and soaping process, and will no longer stick to the fiber, so as to achieve a certain color fastness. After research, most of the hydrolyzed dyes, unfixed dyes and auxiliary impurities remain in the aqueous solution of the capillary network between the fabric fibers, and some are also distributed in the pore network in the fiber Because the dyes in these two states are difficult to wash and easy to remove Therefore, the washing methods and conditions are also different The water washing (soaping) process of reactive dyes is very complex, including physical exchange and dilution, as well as physical and chemical effects.
The initial washing period is mainly for electrolytes. The mass concentration of electrolytes on the fabric should be reduced to less than 1 ~ 2 g / L, then heated up, and soaping agent should be added. If there is a high mass concentration of electrolytes during soaping, it is not conducive to the desorption of hydrolyzed dyes, but also cause dye aggregation and reduce the diffusion speed from the fiber Luttringer believes that high temperature soaping is suitable for hydrolyzed dyes Thomsen believes that 50% high affinity hydrolyzed dyes are washed off at high temperature (95 ℃) However, vinyl sulfone reactive dyes should not be washed at high temperature when the alkali is not washed, let alone with alkali bath soap. The alkali agent should be quickly removed with a large amount of running water in the initial stage of washing The soaping agent can be expressed as follows: fiber · dirt + soaping agent Feng fiber · soaping agent + dirt · soaping agent, in which dirt includes hydrolytic dyes, dyeing auxiliaries and impurities The reverse sign in the balance formula indicates the possibility of existing dirt redepositing on the fiber surface. If the soaping agent has no anti fouling effect, it will cause dirt redepositing on the fiber surface, and the soaping can not be completed well It can also be seen from the equilibrium formula that soaping agent should have strong affinity with fiber and dirt (dyes and impurities.
The anti-staining soaping agent used after reactive dye dyeing is mainly to remove unfixed dyes and hydrolyzed dyes. Therefore, the antifouling soaping agent must have five functions: osmotic adsorption, dispersion, complexation and washing (1) osmotic function, It can reduce the interfacial tension of the working fluid, penetrate between the floating color and the fiber, weaken the adhesion of the floating color on the fiber, and achieve the effect of removing the floating color: (2) the adsorption has directional adsorption on the surface of the dyed fabric, which may be the electrostatic adsorption produced by the ion groups with opposite charges, or the adsorption formed hydrogen bonds in the molecules: (3) Dispersion: the colloidal substance formed after adsorption with floating color falls off from the fiber and then disperses into the working solution to form a stable suspension dispersion system: 4) complexation can shield the metal ions in the dye solution through chelation to achieve the anti contamination effect: (5) washing can be achieved by chelating dispersant surfactants or their compounding. The detergent is usually formulated by a variety of additives. Besides the above five essential functions, the following four properties must be applied in the external application: 1) less foam in use (preferably no bubble) or short foaming time (2), resistant to hard water, and not affected by the water quality of the plant (3). Not affected by the soaping temperature, it has anti fouling effect at various temperatures.
