How to do printing and dyeing without a drop of water?
The clothes that people wear every day are often inseparable from an important process - printing and dyeing.
China has become the world's largest producer, consumer and exporter of textiles. Since the reform and opening up, China's textile industry has gradually become a global livelihood support industry, and the total output value has increased by more than 140 times. Among them, printing and dyeing in the textile industry chain energy consumption and water consumption is larger, waste water discharge is more, printing and dyeing 1 ton of pure cotton yarn needs to consume about 120 tons of water, of which the dyeing process accounts for up to 65%, a large amount of water consumption has become an important problem restricting the sustainable development of the industry.
In the face of accelerating the comprehensive green transformation of economic and social development, which is the only way to achieve sustainable development, the textile industry is facing multiple tests of not only serving a good "rice bowl", but also promoting energy saving, water saving and carbon reduction.
In Foshan City, Guangdong Province, greening and digitalization are quietly reshaping the ecology of the textile industry. A new technology of anhydrous dyeing is gradually reaching Chinese consumers and even facing a broader international application market.
At the 2024 China International Textile Fabrics and Accessories (Autumn and Winter) Expo, the booth of Anhydrous Dyeing Technology attracted the attention of visitors from the United States, France, Japan, Vietnam and other countries. Consumers can access the traceability system through the NFC (Near Field Communication) function on the apparel product tag, and can intuitively understand the production data of the whole chain from fiber, yarn, fabric to ready-to-wear, especially the water-saving contribution behind each product, and jointly witness the future of green textiles.
"Anhydrous dyeing is specifically to use organic solvents instead of water as the medium for dyeing, and the dyeing and coloring process does not use water at all, and the dyeing process does not need to add salts for dyeing, which can achieve or even exceed the effect of traditional water bath dyeing. In the whole process of dyeing, there is almost zero wastewater discharge, which greatly reduces the impact on the environment. In front of the booth, the staff of Guangdong Yiwei Environmental Technology Co., Ltd. (hereinafter referred to as Yiwei Environment) gave a detailed explanation.
From facing the "three highs" of high energy consumption, high water consumption and high pollution, to becoming a "water-saving top student" in the printing and dyeing industry, how to achieve a breakthrough in anhydrous dyeing technology?
Reactive dye dyeing typically requires a large amount of water and chemicals for pre-treatment, followed by dyeing, washing, and post-treatment. The R&D personnel found that the use of recyclable non-aqueous media instead of water can effectively avoid the hydrolysis side reaction of reactive dyes, and there is almost no need for post-dyeing soaping, thus simplifying the entire dyeing process.
Compared to traditional dyeing methods, anhydrous dyeing technology can reduce total water consumption by up to 95%. Simplifying the dyeing process not only reduces water and energy consumption, but also significantly reduces the time required for the entire dyeing process from 12 hours to 6 to 8 hours with traditional methods. It has been calculated that the dyeing water used by this technology is reduced by 95%, the salt consumption is reduced by 100%, the chemical consumption is reduced by 73%, the recycling rate of non-aqueous media is over 99.8%, and the production efficiency is increased by 50%.
In fact, technological innovation does not happen overnight.
Since 2013, Yiwei Environment has invested more than 5,000 yuan to devote itself to the research and development of reactive dye anhydrous dyeing technology. In 2017, this technology was selected as a national key R&D project of the Ministry of Science and Technology, and at the same time, it has become a cutting-edge scientific and technological research technology in the "Technical Guide for Green Environmental Protection Development of Printing and Dyeing Industry (2019 Edition)" of the Ministry of Industry and Information Technology. In January 2022, the anhydrous dyeing technology was rated as an internationally leading and industry-first technology by the expert group of the China National Textile and Apparel Council.
In April 2023, the reactive dye anhydrous dyeing technology successfully achieved industrial mass production in Gaoming District, Foshan City, Guangdong, and now the series of ready-to-wear and technology has been unveiled at the 2024 China International Textile Fabrics and Accessories (Autumn and Winter) Expo, and the water-saving road of waterless dyeing has been explored for more than ten years.
"Waterless dyeing technology is not only an innovative exploration of green development, but also a double tribute to environmental protection and technological change." Xiao Feng, general manager of Yiwei Environment, defined the original intention of brand development in this way.
In the market economy, enterprises are the main body of market economic activities, and the government plays the dual role of managers and service providers. In recent years, Guangdong Province has vigorously promoted water-saving technologies to improve the water-saving efficiency of the industry, investigated the subdivision scenarios of various large water users, benchmarked the advanced water efficiency of similar scenarios around the world, formed a water-saving technology library, product library, project library and excellent practice cases of water-saving actions suitable for local areas, and organized high-water-consuming industries to promote and popularize advanced technologies such as watermark-free dyeing and zero sewage discharge, so as to accelerate the development of water-saving industries.
"We will give full play to the guiding role of water conservancy science and technology innovation funds, and support and drive more enterprises to carry out R&D investment and market application of water-saving technologies." Li Haowen, a first-level researcher at the Guangdong Provincial Water Conservation Office, said.
The "Regulations on Water Conservation" issued and implemented this year clearly pointed out that the state should improve policies and measures to encourage and support the development of water-saving industries and scientific and technological innovation, strengthen the capacity building and industrial application of water-saving scientific and technological innovation, and strengthen the supporting role of scientific and technological innovation in promoting water conservation.
Not only waterless dyeing technology, not only the textile printing and dyeing industry, but also more disruptive technologies and leapfrog innovations will emerge in the future, so that the road to water saving will be wider and wider.
