Printing And Dyeing Clothes Do Not Use Water &Nbsp; CO2 Can Be Used.

We all need to wear clothes, but you may not realize it.

But now a new environmental dyeing technology is trying to change that.

In June of this year, the "supercritical carbon dioxide water free dyeing technology and engineering equipment" and the "non fiber dyeing of disperse fiber and garment products" jointly completed by Dalian Polytechnic University and Guangming Chemical Research and Design Institute were approved by the Liaoning provincial science and technology department for scientific and technological achievements appraisal.

The reporter went to Dalian Industrial University to interview professor Zheng Laijiu, head of the technology.

Professor Zheng Laijiu said that in order to solve the pollution problem in the textile and dyeing industry, Dalian Industrial University has taken the lead in the study of supercritical carbon dioxide water free dyeing technology for natural fibers since 2001. With the recovery of industrial carbon dioxide as carrier, dyes were dyed on textiles in the super marginal state, and the unique technology of one-step extraction dyeing was invented.

Unlike traditional dyeing processes, the technology uses carbon dioxide instead of water, which not only saves a lot of water resources, but also enables industrial production of carbon dioxide to be recycled.

The process of dyeing is to dye dye and loose fiber raw materials into a supercritical carbon dioxide dyeing device. The device is a sealed tank. Each tank can carry about 15-25 kilograms of raw material for dyeing at a time.

When the raw materials are loaded, carbon dioxide is injected into the device, and then the supercritical state is reached under certain temperature and air pressure conditions, so that dyes can be dyed through supercritical carbon dioxide to fiber raw materials.

At present, the dyed products produced by this technology have been tested by the Liaoning textile fiber testing center, and the levelling and penetrability are good. The indexes are obviously better than the traditional dyeing methods.

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Three environmental characteristics of waterless printing and dyeing

Keywords 1: water saving

Zheng Laijiu said that there are more than 400 printing and dyeing enterprises above Designated Size in China, and more than 30 billion cubic meters of wastewater are discharged through industry statistics.

After the achievement has been popularized, 50% enterprises can be replaced by anhydrous printing and dyeing, and each year they can save about 1 billion 500 million cubic meters.

Keywords 2: reduce sewage

No longer use water in dyeing process, naturally no longer produce waste water.

The discharge of sewage from traditional dyeing contains a large amount of residual dyes and organic solvents. The discharge of pollutants into the environment will not only produce air pollution, but also produce water pollution. The use of supercritical water free dyeing can completely avoid the emission of pollutants and harmful gases.

Keywords 3: reduce carbon emissions

Another major feature of anhydrous dyeing is the recovery and utilization of carbon dioxide.

Zheng Laijiu, for example, takes the 100L device as an example. The supercritical carbon dioxide water free dyeing equipment can put in 700 kilograms of carbon dioxide at a time, which means that 700 kilograms of carbon dioxide can be recovered.

Environmental literacy class

What is supercritical fluid?

Supercritical fluid means that the temperature and pressure of the fluid are above its critical temperature and critical pressure, that is, it is in supercritical state.

The supercritical state is neither liquid nor gas, but also has the advantages of liquid and gaseous state. It can easily spread like gas, and on the other hand, it has strong solvency like liquid.

A fluid under supercritical conditions can control some physical and chemical properties by regulating pressure.

It is based on these characteristics that it has been widely used in food, bioengineering, chemical industry, environmental protection and other fields.