Nonwovens made of recycled carbon fibers (rCF) and thermoplastic (TP) fibers have excellent economic and ecological potential. In contrast to new fibers, recycled carbon fibers are significantly cheaper, and the CO₂ footprint is mostly compensated by energy savings in the first product life cycle. The next step for this promising material is its industrial serial use. Therefore, we analyzed the process chain from fiber to composite material. Initially, the rCF length at different positions during the carding process was measured. Thereafter, we evaluated the influence of the TP fibers on the processing, fiber shortening, and mechanical properties. Finally, several nonwovens with different TP fibers and fiber volume contents between 15 vol% and 30 vol% were produced, consolidated by hot-pressing, and tested by four-point bending to determine the mechanical values. The fiber length reduction ranged from 20.6% to 28.4%. TP fibers cushioned the rCF against mechanical stress but held rCF fragments back due to their crimp. The resulting bending strength varied from 301 to 405 MPa, and the stiffness ranged from 16.3 to 30.1 GPa. Design recommendations for reduced fiber shortening are derived as well as material mixtures that offer better homogeneity and higher mechanical properties.

A major obstacle to textile recycling is the presence of dyes, which limits the reuse of fibers in high-value applications. Despite previous studies on, cotton decolorization, the systematic development of an optimal formulation that preserves fabric integrity remains lacking. This study addresses this gap by investigating a decolorization method for mixed-dyed cotton textiles that enables successful redyeing while preserving fabric quality. Reactive and vat-dyed cotton fabrics were treated with sequential reductive and oxidative processes, in a full factorial design. The impact of input parameters on tensile strength was evaluated through statistical analysis using analysis of variance at a significance level of α = 0.05. The developed recipe was subsequently validated on post-consumer cotton textiles. Stripping efficiency was assessed using K/S values, and fabric quality was evaluated through tensile strength, pilling, and fuzzing appearance. Temperature showed the strongest influence on dye removal. Fabric strength was significantly affected by temperature and oxidizing agent, and by interactions of temperature with reducing agent and oxidation time. The optimized process achieved 98–99.5% color removal and retained 95% of the fabric’s tenacity. A stripping efficiency of >90% for post-consumer cotton validates the method’s applicability in real-world circular systems.