No pollution, zero emissions. Recently, the Shanghai Textile Chemistry Clean Production Engineering Technology Research Center of Shanghai University of Engineering and Technology cooperated with the Xinjiang Production and Construction Corps to build Xinjiang’s first non-aqueous medium water-less dyeing production demonstration line for loose cotton and cheese yarn in Alar City, which is protecting green water. While Qingshan, based on Xinjiang cotton resources, we will help build a high-quality cotton spinning industry development pattern.
This dyeing production line is designed to have an annual output of 5,000 tons. Since the trial operation in March, while product quality such as color fastness remains unchanged, the operating cost of the entire process has been reduced by about 5% to 10%, and no wastewater is generated during the production process, fundamentally solving the environmental pollution problem in the traditional printing and dyeing industry. . It not only provides an effective solution for the large-scale development of the printing and dyeing industry in Xinjiang, but also provides a technical path for my country’s printing and dyeing industry to break through pollution bottlenecks and transform to green development.
The cooperation between the two parties began in 2019 with Professor Wang Jiping from Shanghai University of Engineering and Technology Entrusted by the Xinjiang Production and Construction Corps, the team strives to solve the problem of high-salt dyeing wastewater discharge in the printing and dyeing industry, make large-scale cotton textile dyeing possible, and provide technical support for the development of the entire textile and clothing industry chain in Xinjiang. After unremitting efforts, the team’s “non-aqueous medium water-less dyeing technology with reactive dyes for cotton fiber and bobbin yarn” has made breakthrough progress.
According to the traditional printing and dyeing process, it takes 1 ton of cotton fiber to dye One ton of salt and 100 tons of water produce the same amount of pollutants and water at the same time. It is classified as a heavily polluting industry by the country. The focus of technical research in the industry has always been on the end of the industry – sewage treatment. Professor Wang Jiping moved the goal of pollution control to the production end, innovating in printing and dyeing technology, using new methods to dye 1 ton of cotton fiber without salt, only 0.25 tons of water, reducing the dyeing time by 20%, and the final solid waste generated It can also be made into fertilizer and the recycled water produced can be reused.
”This is a brand new technical path, the biggest feature It means no salt compounds are used, no waste water is produced and the dye utilization rate is particularly high.” Wang Jiping introduced the working principle of “non-aqueous medium with less water and no salt, zero discharge of sewage dyeing”.
”Our method is to add a small amount of water and Required reactive dyes. The dye will not dissolve into the hydrophobic medium, but will only dissolve into a small amount of water droplets. In professionally designed dyeing equipment, the water droplets with dissolved dye will come into even contact with the non-aqueous medium and cotton fibers. You must know that cotton fiber is a hydrophilic fiber. They particularly ‘like’ the ‘water droplets’ carrying dye. They will gradually grab the dye during the dyeing process and complete the reaction with the dye. The utilization rate of the dye can reach more than 90%. . In this technical path, the entire dyeing process does not require the addition of the salt compound sodium sulfate, and the dyeing can be completed by utilizing the affinity of water droplets and fibers.” Another core element of this technology is that the non-aqueous medium and water recycling process also adhere to the principle of recycling. The principle of utilization ensures zero pollution to the environment.
Using this process can save 100% of salt compared with traditional processes , save more than 20% of dyes, reduce wastewater emissions in the dyeing stage by nearly 100%, and reduce wastewater emissions in the rinsing stage by more than 95%. While achieving the goal of substantial water conservation and emission reduction, it can also reduce the intensity and difficulty of terminal treatment of wastewater.
Regarding the application prospects of technology, Wang Jiping is very optimistic: “Xinjiang’s Cotton production accounts for allThe domestic proportion has reached 90%. In the past, due to technical constraints, raw materials could only be exported from Xinjiang. Now, raw materials can be deeply processed, which not only drives economic development, but also solves some employment problems. ”
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