Covestro, based in Germany, has developed elastic textile fibers using CO2-based thermoplastic polyurethane (TPU). The elastic fibers are made with a chemical precursor, cardyon, which is partially made of CO2 instead of oil. The fibers are made from CO2-based TPUs using a technique called melt spinning, in which the TPU is melted, pressed into very fine threads and finally processed into a yarn of endless fibers. The materials can be used for stockings and medical textiles and might replace conventional elastic fibers based on crude oil.

Unlike dry spinning, which is used to produce conventional elastic synthetic fibers such as elastane or spandex, melt spinning eliminates the need for environmentally harmful solvents. A new chemical method enables carbon dioxide to be incorporated in the base material, which also has a better CO2 footprint than traditional elastic fibers. The CO2-based material could be a sustainable alternative to conventional elastic fibers in the near future.

What makes the CO2-based TPU fibers so special is their properties. They are elastic and tear-proof and so can be used in textile fabrics. Companies from the textile and medical engineering sectors have already tested the CO2-based fibers and processed them into yarns, socks, compression tubes and tapes.