Lately, the interest in reuse and recycling of textiles has increased enormously due to the EU waste directives. Especially B2B textiles made from polycotton, like flat or towel linen or workwear processed at industrial laundries (textile service), can contribute to resource savings as well as environmental relief after utilization if they are brought back to fiber applications. Nevertheless, the change towards a textile circular system after the utilization phase and the necessary material cycles are still in their infancy. The main challenges are the supply and assurance of defined, sorted and sufficiently large waste streams by automatic sorting of waste textiles regarding their material composition as well as the logistical processes to the recycling company. Therefore, one objective of the presented project “KICKup” explored by Dibella GmbH (Bocholt, Germany) and Hochschule Reutlingen (Reutlingen, Germany) is to develop a consistent and simple solution for all industrial laundries to implement a fully automated sorting system for textiles which reduces costs and makes closed-loop circulation profitable. This solution, serving as a basis for the logistical processes, increases the amount of usable post-consumer waste and reduces the amount of raw materials used. After separation of cotton and polyethylene terephthalate (PET), the cellulose pulp from the cotton part can already be used to partially substitute virgin material in cellulosic regenerated fibers, e.g. new Lyocell Refibra™ fibers (Lenzing). Nevertheless, the polymer length of cotton fibers is strongly reduced during the first recycling process by converting them into Lyocell fibers and processing the fibers. Therefore, a second objective of “KICKup” investigated by Hochschule Niederrhein (Mönchengladbach, Germany) is to study the change of quality of cotton and Lyocell fibers (Refibra by Lenzing, partially produced from cotton) regarding the change of material composition and degree of polymerization during use and laundry cycles of flat linen. The project KICKup (Ref. No. 38265/01) is sponsored by the German Federal Environmental Foundation (DBU – Deutsche Bundesstiftung Umwelt).