Green Dyeing And Finishing Ensures The Safety Of Production And Use Of Nonwoven Products

Recently, Mr. David Chandler, director of the Department of safety and technology products of the International Association of industrial textiles, pointed out that the future nonwovens will develop along the direction of green and Ecologicalization in the nonwoven technology forum organized by the American Nonwoven Industry Association.

The development is becoming more and more obvious. It is imperative to create ecological nonwoven fabrics.

The two criterion is whether products are environmentally friendly.

Mr. David Chandler said that the definition of ecological nonwovens in a complete sense includes 4 aspects: renewable and reusable raw material resources; no adverse effects on environment will be produced during production and processing; in the process of use, consumers' safety and health and environment will not be damaged; and after abandonment, they can be degraded under natural conditions or cause new pollution to the environment.

Liu Jianyong, a professor at the Industrial University, points out that the ecological dyeing and finishing of nonwovens is an important research direction in the future production of nonwovens, and is also the only way to ensure the safety of production and use of nonwoven products.

However, due to the fact that there are still many technical and cognitive problems in the implementation process, the identification standards of ecological nonwovens are divided into two categories.

One is the whole ecological concept represented by "Eco-Label" in Europe.

According to this standard, the fibers used in ecological nonwovens should not be polluted in the process of growth or production, and will not pollute the environment. The raw materials used in ecological nonwoven products are renewable resources or available wastes, which will not cause the imbalance of ecological balance and the exploitation of predatory resources, that is, the concept of so-called generalized eco textiles.

Because of this standard

At present, there are very few nonwovens that meet the requirements.

Another point of view is the International Eco textiles research and Inspection Association (Oeko-Tex), composed of 13 research institutions in Germany, Austria and Switzerland. It represents the limited ecological concept, the so-called chivalrous eco textiles.

Because of the operability of this view, the current production practice is mainly based on this view, namely, toxicology tests are carried out in the key process of finishing, printing and dyeing, namely, the preparation of ecological textiles, and corresponding signs are made to identify whether they are required for environmental protection and ecological indicators.

In the process of nonwovens dyeing and finishing, the harmful substances mainly include soluble metal salts, formaldehyde, pentachlorophenol, pesticides, carcinogenic dyes and so on.

Generally speaking, the main sources of ecological and toxin hazards to nonwoven products are dyeing and finishing auxiliaries, raw materials for printing and dyeing auxiliaries, and harmful substances produced during dyeing and finishing auxiliaries.

Gavin, the responsible person of the International Eco textiles research and Inspection Association, said at the global eco Textile Conference that at present, the EU Member States, including Germany, are discussing the issue of disabling the special dyeing and finishing auxiliaries for some nonwovens, but so far, no banned dyes and auxiliaries have been put forward. This is mainly due to the opacity of the molecular structure and the compounding ingredients of dyeing and finishing auxiliaries, which increases the difficulty of disabling auxiliaries.

Shen Ming, associate professor of Anhui Engineering University, pointed out that although there are definite boundaries in some projects, such as the technical labeling of eco industrial textiles stipulated in Oeko-Tex Standard 100, most of the projects do not have clear standards, and they can only refer to the regulations and practices of some other countries, which are relatively vague.

In order to reduce waste water and exhaust gas pollution, the measures currently adopted include the use of less polluting products, the reduction of the amount of printing paste into the waste water, the polymerization of products with low residual monomer content, and the low formaldehyde content of adhesives, crosslinking agents and other compounds. Only additives are used with non-toxic solvents to produce harmful substances which are harmful to human beings and the environment.

Shen Ming said.

Similarly, formaldehyde, as a commonly used crosslinking agent, is widely used in various finishing processes of nonwovens. However, formaldehyde is a toxic substance to native cells of biological cells and has strong stimulation on the human body.

Liu Jianyong pointed out that formaldehyde is used as a reactant to improve the durability of dyeing and finishing auxiliaries on nonwoven fabrics, but the free formaldehyde and formaldehyde released from dyeing and finishing auxiliaries cause excessive formaldehyde content on the nonwoven fabric, resulting in the formaldehyde content on the cloth may exceed the limit specified in the relevant regulations.

Although the regulations and standards of various countries have strictly restricted the content of free formaldehyde in products, for example, the formaldehyde content of clothing and textiles that contact the skin can not exceed 75mg/kg. The formaldehyde content of clothing and textiles and textile industrial fabrics that do not directly contact the skin can not exceed 300mg/kg, but the effect is still not ideal.

However, it is worth mentioning that an American company co operating with the International Association for the study and inspection of eco textiles announced that the company is studying a biodegradable dispersant known as acid formaldehyde.

This kind of dispersant is not affected by formaldehyde limitation, and its biodegradability is very strong. About 70%~75% of the dispersant can be biodegraded. This additive is expected to be put into the market by the end of this year, which will bring a positive positive impact on the protection of the ecological environment.