top of page
  • Dena Dyes

Fabric Dyeing in Supercritical CO2



The textile sector is at the top of the water consuming industries. Excessive water consumption occurs in almost all steps of coloring processes. In textile dyeing, pre/post finishing and washing baths, water is used indirectly, while steps such as heating, cooling and steaming are used directly. In addition to all these, many chemicals used during these processes cause environmental pollution. At the present time, a large number of researches continue on environmentally friendly, sustainable and innovative methods and technologies that will reduce the carbon footprint in order to both reduce environmental pollution and use

limited water and energy resources efficiently.




In general, a substance exists in three states: solid, liquid, and gas. However, under a certain temperature and pressure, the (critical) substance is called as a supercritical fluid, since it is neither liquid nor gaseous. The density of the supercritical fluid is the same as the density of the liquid state, but 200-400 times more than the density of the gaseous state, which allows it to dissolve large and non-volatile molecules. Carbon dioxide, which is environmentally friendly, recoverable, non-flammable, non-toxic, chemically inert, has a low

critical temperature and pressure value, is the most commonly used substance in the supercritical condition due to these properties.


Reactive, direct and acid dyestuff are not sufficiently decomposed in supercritical carbon dioxide. Synthesis of special dyestuff suitable for this method is still ongoing. It is even aimed that some reactive dyestuff under development dye also synthetic fibers. In this way, it is clear that blended products will be painted in one step.


In addition, natural fiber and dyestuff cannot bond in supercritical carbon dioxide environment, unlike in aqueous medium. Because supercritical carbon dioxide has a density close to liquids, hydrophobe is very effective in dissolving dyestuff. For this reason, successful results have been obtained especially in dyeing synthetic textile materials.


Dyeing process of synthetic fabrics in supercritical carbon dioxide fluid media;


1. Dissolution of dyestuff in supercritical carbon dioxide environment

2. Transfer from dyestuff to fiber

3. Adsorption of dyestuff by fiber

4. Diffusion from dyestuff to fiber occurs in four steps.


Compared to conventional dyeing method and supercritical carbon dioxide (anhydrous) staining medium, at the method of anhydrous dyeing method;


-It clears off wet treatment and drying processes. Thus, water and energy savings are provided.


-Since wet treatment is not required, the waste water also does not occur.


-Although device and infrastructure costs are high in the initial investment, it can be said that the operating cost is lower because fewer devices are needed throughout the dyeing process than the conventional method.


-Dissolved dyestuff becomes powdery when the pressure on carbon dioxide is eliminated, so that the residual can be recovered.



HAKAN TÜRKSEVER

Supply Chain Manager

 

Referanslar:

1.Odabaşoğlu H.T.; Avinç O.O.; Yavaş A. (2013). Susuz Boyama, Tekstil Mühendis, 20:90, 63-79.

2.http://www.dyecoo.com (Erişim Tarihi/Available Date: 31.03.2021)

3.http://www.adidas-group.com/en/sustainability/products/sustainability-innovation/#/adidas-drydye/ (Erişim Tarihi/Available Date: 31.03.2021)

4.Elmaaty T.A.; Kazumasa, H.; Elbisi, H.; Mousa A.; Sorour H.; Gaffer G.; Hori T.; Hebeish A., Tabata I, Farouk R. (2020). Pilot Scale Water Free Dyeing of Pure

Cotton Under Supercritical Carbon Dioxide, Carbohydrate Polymer Technologies and Applications, https://doi.org/10.1016/j.carpta.2020.100010

5.Nandhakum R.; Kaviyarasu R., Kalidass M. (2012). Dyeing of Fabrics Without Water: A Review, The Indian Textile Journal , 2, 37-39.

Comments


bottom of page