Study Of Wool Dyeing Behaviour In Ethanol-water Mixed Solutions

Conventional boiling dyeing of wool leads to the damage of fiber and the reduction ofbreaking strength, which is detrimental to the following procedures such as spinning, weavingand brought about the high cost of waste water disposal. This essay provides a solution ofethanol-water mixtures as dyeing liquor which is beneficial for achieving both a better dyeingperformance and mechanical properties. Given that the organic solvent is able to be recycledand the dyeing auxiliaries are not required to add, this novel dyeing method can reduce theamount of water, diminish environmental pollution and decrease the cost in sewage treatment.This topic employed four different kinds of dyes in terms of reactive dye, strong acid dye,weak acid dye and neutral dye to dye wool in various concentrations of ethanol-watermixtures. And this paper studied the optimum dyeing recipes and technologies. The resultsshow that the absence of auxiliaries and the sealed dyeing system are suitable for the dyeingof reactive dye. The other three kinds of dyes should be dyed without auxiliaries and inunclosed dyeing system. The ratios of ethanol and water, the resource of wool, dyeingtemperature and dyeing time were also further investigated as the key factors which exert vitalimpacts on color strength, dyeing levelling and dyeing fastnesses in this essay. The resultsindicate that the addition of ethanol boosts the color strength of wool. The perfect colorstrength for wool woven fabrics can be obtained in the dyeing bath which consists of50%ethanol,50%water and reactive dye. Meanwhile dyeing liquor comprising75%ethanol and25%water is the best condition for wool fiber to achieve perfect color strength. The optimalratio for wool fiber and woven fabrics dyed in strong acid、weak acid or neutral dye isconsistent with the best proportions of wool fiber dyeing. The dyeing of wool can reachequilibrium at95℃for60min in ethanol-water mixtures, thus improving the levellingproperty and the staining fastness. Finally the wool woven fabrics dyed in reactive dye in thepresence and absence of auxiliaries and acid, the dyeing temperatures were analyzed. It can beconcluded that breaking strength can be increased in the lack of auxiliaries and the presenceof acid. The breaking strength exhibits various breaking strength in different dyeing temperatures, wool fabrics dyed in75℃take the first place in terms of breaking strength, thefollowing is95℃,85℃is the least. At the same time, the wool woven fabrics dyed in50%and75%ethanol perform better in breaking elongation.