Transforming mechanically recycled cotton and linen from post-consumer textiles into quality ring yarns and knitted fabrics

Fibre mechanical recycling is an efficient strategy to turn non-reusable post-consumer textiles into new textile products with a minimal environmental impact. It helps reduce the need for primary raw materials and prevents the incineration or landfill disposal of textile waste. To foster textile circularity, it is essential to use these recycled fibres as secondary raw materials for textiles. The focus of our study was, therefore, to create quality yarns for making knitted fabrics for long-lasting garments. In this study, mechanically recycled post-consumer cotton and linen were ring-spun into yarns. Recycled cotton (rCO) was blended with virgin cotton (CO) in ratios of 30/70, 50/50, and 70/30, and with virgin viscose (CV) at a 50/50 ratio. Recycled linen (rLI) was blended with virgin viscose in ratios of 30/70 and 50/50. The yarn appearance, breaking tenacity, and elongation were evaluated and compared to virgin viscose and cotton yarns. The knitting performance of rCO/CO 50/50 yarn and reference 100 CO yarn was assessed by knitting different knit structures and pattern designs using a flatbed knitting machine. Additionally, the abrasion resistance of the two yarns knitted into single jersey fabric was tested using the Martindale method, and the samples were inspected using scanning electron microscopy. Increasing recycled cotton and linen content in ring-spun yarns decreased yarn strength and increased the uneven appearance. In addition, the rCO/CO jersey fabric showed higher wear under abrasion than the reference 100 CO fabric. The knit structure and pattern design had a central influence on knittability and fabric appearance when using yarn containing recycled fibres. Therefore, these factors should be considered to promote the use of recycled fibres for creating long-lasting textile products.