Environmental pressure on dyeing technology

The biggest pressure on the dyeing process is still the environmental pressure, which at present mainly includes the substitution of banned dyes containing carcinogenic aromatic amines and heavy metals (hexavalent chromium, etc.), strict selection of all kinds of chemicals, management of the three wastes, water conservation and energy saving, and monitoring and control of ecological standards of the products, etc. If these problems are not solved, the survival of dyeing and processing will also be problematic.

Eco-dyeing is a systematic project, first of all, we must rationally select raw materials, including fibers, dyes, auxiliaries and chemicals. Secondly, we should establish ecological production, reduce the consumption of dyes, auxiliaries and chemicals, water and energy, and effective management of the three wastes, sewage discharge standards. Finally there should be strict monitoring of products and control of their ecological standards to produce safe and healthy products.

Eco-textiles should comply with Eco-Tex Standard 100 environmental standards, that is, with the "six no: does not contain carcinogenic aromatic amines or will not be cleaved to release carcinogenic aromatic amines, does not contain allergic dyes, auxiliaries and chemicals, does not contain heavy metals, does not contain formaldehyde, does not contain absorbent organohalides and not easy to produce pollution of the environment or the three-waste treatment. Up to standard. These environmental and ecological requirements continue to improve, the future requirements are more stringent.

In the textile dyeing process, the main ecological problems facing the current water conservation, energy saving and reduce sewage discharge.

Dyeing processing water consumption, sewage discharge is also large, not only due to the rising price of water and increase costs, more serious is the world, including our country, the lack of water resources, while the sewage treatment and discharge standards are also becoming more and more stringent. The use of short flow dyeing, small bath ratio dyeing, efficient washing can greatly save water, but also reduce the discharge of sewage. In addition, the realization of water recycling, repeat water and improve the efficiency of sewage treatment, water recycling and reuse. Currently there are mainly the following three ways of sewage treatment:

(1) membrane filtration;

(2) adsorbents to remove dyes and chemicals;

(3) chemical or high-energy rays (ozone-ultraviolet treatment) decolorization;

This treatment of sewage is generally still difficult to be used for dyeing, and also after some treatment to be able to use. More practical is that the treated water is used in different occasions.

Dye recycling is also the focus of research, recycled dyes reuse to dyeing also encountered a lot of problems, it is reported that indigo recycling has been reused.

The ecological standard testing and control of the production process and products is getting more and more attention, and the requirements of various countries are getting higher and higher, which is an important index of product quality.

2. Dyeing technology forecast

Future dyeing process, first of all, clean processing, and textiles are not only required to have cold and warmth, beautify the human body, but with high-tech performance and a variety of functional products. Therefore, the future of dyeing especially in the following areas will be prioritized.