China is a big country of textile printing and dyeing, and the cotton fiber printing and dyeing industry mainly uses reactive dyes and adds inorganic salts to promote dyeing. However, the amount of inorganic salt is large, the water consumption is large, the dye color fixation rate is low, the color degree is high, the treatment is difficult, and the waste of resources and energy is serious. Xinjiang is short of water resources, the ecological environment is fragile, a large number of inorganic salts are not allowed to discharge, forcing enterprises to carry out high-cost desalination treatment, seriously restricting the high-quality development of Xinjiang cotton industry chain, and the research and development of new salt-free dyeing technology is imminent.

The cotton fiber salt-free green dyeing technology developed by Professor Zhang Shufen's team at Dalian University of Technology was approved as a science and technology development plan project of Xinjiang Autonomous Region's "Silk Road Economic Belt innovation-driven Development Pilot Zone and Wuchangshi National Independent Innovation Demonstration Zone" in 2023. Recently, the project held a "100 kg salt-free dyeing amplification experiment" witness meeting, the project achieved 100 and 200 kg of cotton fabric salt-free dyeing, dye fixation rate reached more than 95%, bright and uniform color, color fastness excellent.

The experts agreed that the project successfully overcome the technical problems and bottlenecks of salt-free dyeing of cotton fibers, achieve zero use of reactive dyes dyeing inorganic salts, greatly help to improve product quality and follow-up wastewater treatment, and can achieve industrial application, with the leading level at home and abroad. In view of the large production of local yarns and fabrics in Xinjiang and the growing demand for printing and dyeing, the implementation of the project will inject strong impetus into the green upgrading of the printing and dyeing industry in Xinjiang.

In the next step, the project will make breakthroughs in cotton fabric on a larger scale and dye varieties, form an implementation plan for wastewater recycling, and realize the green printing and dyeing technology of the whole process. This technology is a revolutionary technological breakthrough in the textile printing and dyeing industry, and after its implementation, it will enhance the core competitiveness of the cotton industry chain of Xinjiang cotton and textile and garment industry clusters, and promote the high-quality development of the entire chain of the cotton industry.

Source: Chinese Journal of Science