Dyeing with supercritical CO2 – finally a success story?

Summary

Dyeing in supercritical CO₂ could finally be on track for success after 25 years of development. Originally an idea of German universities, it was developed and brought to market by the Dutch start-up company DyeCoo. I have already covered the same story in 2012.

With this innovative, environmentally friendly and water-free dyeing technology, today sportswear textiles made of polyester are produced in Asia for the brands of adidas and Nike. Carbon dioxide (CO₂) turns to a supercritical state at a pressure higher than 73.8 bar and a temperature higher than 31.1 ° C (Figure 1). Supercritical is a condition with high solvency power and excellent permeability. The use of supercritical carbon dioxide (hereinafter abbreviated as “scf-CO₂“, said scf stands for “supercritical fluid”) in extraction methods is known for a long time, e.g. for the extraction of caffeine from coffee. The concept of dyeing from scf-CO₂ has long been on everyone’s lips in the industry as well as in academia.