The focus of the sub-project is on the extraction of high-quality natural fibers from regionally available plant-based raw materials for use as reinforcing material in natural fiber-plastic composites. The development of economically and ecologically viable technologies and processes is practice-oriented, i.e. in close cooperation with regional industrial companies, research institutions and agricultural associations. In order to ensure the efficient utilization of raw materials, the organic and inorganic residues resulting from the fibre production process are made usable by means of appropriate processes or plants (e.g. ion exchangers, filtration units) and fed into further material or energy applications (e.g. biogas production, production of natural fertilizers).