Sustainable and green process for recycling waste wool textiles into high-quality protein fibers on a pilot scale

For the first time, waste wool textiles have been recycled into high-quality protein fibers via protein dissolution. Traditional mechanical wool recycling, with serious damage to protein fibers and limited color styles on fibers, only boosts 5% of post-consumer wool recycling rate. Other recycling is hindered due to the failure of dye removal and protein dissolution. Here, we have developed green and sustainable processes of complete dye separation, establishment of desirable molecular entanglement in protein dissolution, and recovery of crosslinkages in spun fibers. More than 80% of waste wool was recycled into protein fibers, which were comparable to virgin wool fibers, with retention of more than 90% of mechanical, wet, and dyeing properties of virgin wool. Recycled dyes, completely separated from proteins via the disruption of molecular interactions in wool and controlled protein precipitation, were reused and demonstrated the desired dyeability without generating dye wastes.