Due to the continuous optimization of cutting plans, the cotton scrap size resulting from the cutting of components for clothing production (post-industrial residues) is often considered insufficient to obtain fibres with the proper length to produce a new yarn through mechanical recycling processes; so it is important to search for other applications for these wastes. In this context, small pieces of cotton were submitted to a shredding process to obtain recycled fibres. Cotton small pieces and recycled fibres were then submitted to a refining process to achieve refined fibres. Using these materials alone and in blends with refined and unrefined bleached eucalyptus kraft pulp (BEKP), wet-laid nonwovens were developed and characterized. An analysis of the results revealed that the replacement of unrefined BEKP by 70% cotton waste fibres in wet-laid nonwovens, reducing the use of virgin raw material, enhances the structures’ mechanical properties by 80% and 14%, for small pieces or recycled fibres, respectively. Additionally, refining small pieces of cotton seems to be more promising than refining recycled fibres, because less steps are required to obtain wet-laid nonwovens with better mechanical properties. These results highlight the potential of this approach to be explored further for different products and end applications.

Functionalized wet-laid nonwovens were developed from recycled cotton fibres, including spinning process residues (SPRs) and cotton fabric scraps (CFSs), blended with refined bleached eucalyptus kraft pulp (BEKP), demonstrating the valorisation of textile waste into high-performance materials. A two-step surface functionalisation strategy was applied, combining spray deposition of a polyamide-amine wet-strength resin with padding using carnauba wax, polyurethane dispersion and their combination. SEM and ATR-FTIR analyses confirmed successful functionalization of the cellulosic nonwovens without affecting their structure. The surface modification induced a hydrophilic-to-hydrophobic transition, with SPR-based nonwovens showing higher contact angles (>130°), lower water uptake and slower liquid penetration. The applied functionalization strategies suppressed liquid strike-through (STT) across both nonwovens’ formulations. Mechanical performance was also enhanced. SPR-based nonwovens modified with the combined agents showed increases of 59% and 90% to 30/70% SPR/BEKP and 70/30% SPR/BEKP, respectively, while CFS-based nonwovens exhibited increases of 148% and 207% for the same formulations. Wet strength was noticeably improved, exceeding instrumental limits in SPR systems functionalized with polyurethane dispersion alone as well as with the combined agents. Therefore, this functionalization strategy effectively overcomes the intrinsic hydrophilicity and wet weakness of cellulosic nonwovens, enabling to be applied in packaging, household and other technical applications, while promoting the circular economy.