In Germany, Covestro and its partners, foremost the Institute of Textile Technology at RWTH Aachen University and various textile manufacturers, are developing the production process on an industrial scale to create elastic fibers made with a chemical component that consists in part of CO2 instead of oil. This is a further milestone in the use of CO2 as an alternative raw material and they aim to make the innovative fibers ready for the market. The elastic fibers can be used for stockings and medical textiles, for example, and might replace conventional elastic fibers based on crude oil.
The fibers are made from CO2-based thermoplastic polyurethane (TPU) 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. 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.