The world’s first large-scale waterless dyeing with CO2

Waterless dyeing machine
Waterless dyeing machine

2250L supercritical CO2 waterless dyeing machine

The 2250L supercritical CO2 waterless dyeing machine independently developed by China has been continuously and stably produced at the Qingdao Jifa Group Base for five months and is currently undergoing a major scientific and technological innovation project in Shandong Province based on the key technology of this equipment. Final acceptance. This equipment has realized the large-scale application of supercritical CO2 waterless dyeing technology for the first time. It is currently the largest domestic and the world’s only industrialized demonstration equipment that can run continuously and stably.

Waterless dyeing machine
Waterless dyeing machine

The 2250L supercritical CO2 waterless dyeing machine uses supercritical carbon dioxide as the dyeing medium, gets rid of the use of water and chemical auxiliaries eliminate the generation of wastewater from the source, truly achieves zero discharge of sewage, and saves more than 100,000 tons of freshwater resources every year. It subverts the current situation of high energy consumption and high water consumption in the traditional printing and dyeing industry and provides complete technical standards and equipment specifications for the industry, which is of great significance to upgrading the textile industry, promoting the construction of ecological civilization and the development of low-carbon circular economy.

Waterless dyeing machine
Waterless dyeing machine

Performance

This 2250L supercritical CO2 waterless dyeing equipment can produce 600 tons of polyester fiber cheese yarn per year, and also greatly improves the printing and dyeing efficiency, without the need for cleaning, drying, and other processes, shortening from 8-12 hours of traditional water dyeing to 3- 4 hours. At the same time, the carbon dioxide medium is non-toxic and harmless, and the cost is low. The whole operation process is closed and can be recycled and reused. The thermal energy consumption is only 20% of the original process. The device realizes the automatic control of the large cycle of cheese degreasing and the inner cycle of dyeing, with a high degree of automation, saving manpower, and can remotely display, record, and trace the pressure, temperature, flow, and liquid level of each equipment during the working process.

The white raw yarn enters the dyeing kettle through the dyeing shaft, and the pressure pump then presses CO2 into the system, and the heater immediately heats it. After reaching the specified pressure and temperature conditions, the computer system automatically turns on the circulating pump for dyeing. After cyclic dyeing, the red yarn comes out of the kettle. The process takes less than two hours, compared to seven hours with traditional techniques.

Waterless dyeing machine
Waterless dyeing machine

Development process

China has started the industrial application of supercritical CO2 fluid technology, and has developed anhydrous dyeing equipment. But compared with foreign countries, the start is still 10 years late. In 1989, E. Schollmeyer, the German Northwest Textile Research Center, launched an waterless dyeing technology. In the following two decades, Germany, Japan and other countries have successively invested hundreds of millions of funds to support industrial development, but there has been no successful commercial operation. news. Until 2010, the Dutch DyeCoo company invested and developed two 500L production supercritical waterless dyeing equipment, and cooperated with Thailand’s largest sportswear manufacturer Yeh Group to produce waterless dyed sportswear. Nike also predicted that “DyeCoo’s technology will have a positive impact on the textile printing and dyeing industry. With the increasing scale, a large amount of traditional textile printing and dyeing water will no longer exist, and it will no longer require the use of fossil fuels to heat a large amount of water”. Unfortunately, the device developed in the Netherlands has been forced to stop production due to problems such as insufficient process technology stability, and related assets have also been sold. It can be seen how difficult the industrialization of anhydrous dyeing technology is.

Waterless dyeing machine
Waterless dyeing machine

In 2010, China launched the development of a 100L supercritical dyeing device for the first time. In 2015, the first domestic 500L supercritical waterless dyeing device was successfully commissioned. The first feeding operation was successful, and the dyeing quality exceeded the water dyeing index. The device has been running continuously and stably so far. In 2020, a new round of research and development will be invested and 2250L of supercritical CO2 anhydrous dyeing equipment will be successfully delivered in 2021.

In the development process of each stage, in the absence of domestic basic theory and basic data, in order to solve the key common technical problems, the Chinese R&D team overcame one difficulty after another, and successfully invented the horizontal supercritical dyeing kettle, supercritical Carbon dioxide dyeing kettle, supercritical fluid electric heater, special electric heating furnace for supercritical device kettle body, supercritical fluid separator, intelligent supercritical drying device, intelligent supercritical drying device and drying method have many patents. It is precisely under the tireless joint exploration of the R&D team that it started from small trials of 1L and 5L devices to continuous pioneering breakthroughs in pilot-scale equipment such as 50L, 100L, and 500L, and then to 1200L and 2250L devices.