Investigation And Application Of Water Saving And Emission Reduction New Dyeing Technology For Wool Fiber

In order to guarantee the color depth and various excellent color fastness of the dyeing wool, a long and complicated after-treatment process was needed after the conventional dyeing of wool fiber with reactive dyes such as: soda washing→ washing(several time) →acid neutralization, etc. Meanwhile, the amount of water consumption and sewage discharge were large. With the purposes of solving the problems mentioned above, in this investigation, the in-situ mineralization new technology was presented and obtained based on the micro-suspension dyeing technology for dyeing of wool with woolen reactive dyes. The in-situ mineralization technology was carried out as follow: the dyeing bath need not to be discharged after dyeing and the mineralization series coupling agents were then added into the dyeing bath at certain temperature, while the residue dyes and auxiliaries in the dye bath were decomposed into small colorless molecules, carbon dioxide and water. Thus the effluent chroma and level of fouling of the treated bath can be reduced greatly and backwater dyeing can be achieved.Lanasol CE series reactive dyes for wool with matched micro-suspension dyeing agent XPN were used in the dyeing of wool fiber and the optimized parameters of the in-situ mineralization process were as follow: the dosage of mineralization coupling agent XAM, XBM and XYS were respectively set to 1.0%(owf), 0.6%(owf) and 5.0%(owf), the system was treated at 90℃ for 40 min.Apart from the basic requirement of fastness, color depth and spinning performance in production, compared with the traditional process, The damage of wool fiber in new dyeing process was less, also, the spinning performance of the dyeing fiber was improved. For example, the tie up roller times and parking times were reduced remarkably, the rate of short wool was lower by 21.26%, thus improving its utilization radio during the gilled process. The end-breaking rate of yarn was reduced by 8%, the yarn evenness was better and breaking strength was 7.34% higher than the traditional ones.The water saving radio was up to 98.33% after backwater dyeing 19 times in new technology. CODcr, BOD5, suspended solids of the effluent and effluent chroma were respectively reduced by 97.83%, 97.67%, 97.21% and 99.82%. The in-situ mineralization technology, with extremely promising prospect of popularization and application, achieved residual liquid recycling as well as water saving and emission reduction.