New technology to achieve zero-emission textile dyeing without the need for water

By using the semi-liquid state of the supercritical fluid, the dye can be dissolved, and the inside of the textile can be easily infiltrated to complete the process of dye dissolution-adsorption---staining, which eliminates the main disadvantages of the traditional water dyeing process. Reduce the dyeing cycle from hours to tens of minutes while achieving “zero” emissions, environmentally friendly and efficient. This is the full-chain industrialization model of the “Science-Technology-Engineering-Industry-Market” innovation of the Group, and the independent development of the industrial application of the supercritical CO2 waterless dyeing technology for textile materials and become the world's first and largest intelligent The industrialization production line of water dyeing has huge economic and ecological benefits.

Recently, Yu Jianyong, an academician of the Chinese Academy of Engineering, went to the Jimei Group in Jimo District of Qingdao to investigate the demonstration project of supercritical CO2 waterless industrialization of textile polyester materials. The construction and operation of the waterless dyeing demonstration line of the company marks China. The waterless dyeing process technology is becoming more mature and industrialized to achieve major breakthroughs.

At present, the annual emission of textile wastewater in China is 2.5 billion tons (about 230 West Lake water), of which the printing and dyeing wastewater discharge is 2 billion tons. Due to the dependence of traditional printing and dyeing on water resources and environmental problems caused by wastewater discharge, it restricts the industry. Sustainable development. Therefore, it is urgent to develop a water-less or water-free dyeing technology to solve the bottleneck problem of the development of the printing and dyeing industry from the source. As early as 2014, Jifa Group started the industrialization research and application of supercritical CO2 waterless dyeing technology through industry-university-research cooperation, continuously improved and perfected the water-free dyeing technology, and solved many industrialized production factors such as equipment, process and testing. The key technical problems have overcome the bottleneck of professional components and realized the continuous operation of the "scientific-technical-engineering-industry-market" full chain industrialization mode and equipment. In 2017, the world's first 1200L water-free dyeing industrialization demonstration production line with independent intellectual property rights was built. The continuous operation of the equipment was realized, and a number of dyes suitable for supercritical CO2 waterless dyeing of polyester cheese yarns were tested. Applying for more than 30 patents has laid a solid foundation for industrial application.

The technical principle of the supercritical CO2 waterless dyeing project for textile polyester materials is to put the dye and the dye into the dye pot and the dyeing tank respectively. When dyeing, the liquid CO2 is converted into a supercritical state by heating and pressing system. The dye tank is in full contact with the dye; the supercritical CO2 fluid passes through the dyeing tank containing the dye to realize the adsorption, diffusion and fixation process of the dye; after repeated cycles, the dyeing is finally completed. After dyeing, the CO2 is depressurized, separated from the undyed dye in the separation vessel, and the excess dye is left in the separation vessel, and the CO2 is liquefied by the condenser and recycled to the storage tank for recycling. Wan Gang, deputy general manager of Jimei Group, introduced that the implementation of the industrialization project of supercritical CO2 anhydrous dyeing technology for textile polyester materials is in line with the national “ 13th Five-Year Plan” and belongs to the high-tech field supported by the state. Social construction, the creation of resource-saving and environment-friendly enterprises, and the vigorous development of efficient, energy-saving, environmentally friendly and recyclable new manufacturing processes and equipment have a positive role in promoting.