Design for sorting knitwear: Exploring blended textile wastes and the relationship between sorting, recovery, and recycled blending in yarn manufacture

Background: The problem of difficult-to-recycle textile waste is an ongoing challenge.  One of the issues is the lack of exchange between the recovery sector and design/manufacture of recycled materials. This paper seeks to addresses the gap in knowledge between sorting (in recovery) and blending activities (in manufacture), expanding current design strategies towards textile recovery. To achieve this, the research explores sorting practices of wool/acrylic blends in the mechanical wool recycling industry and applies this knowledge to the design of new yarns. Methods: A bricolage of methods was used to conduct this research in three parts. First, an overview of a previous study by Author1 is presented from which this research builds. Second, field research using conversation methods with the owner of a closed wool recycling company was conducted centring around their material archive. Thirdly, practice research was conducted in a spinning facility where Author1 applied knowledge from part 1 and 2 by designing four recycled yarns. This was supported by interviews with a sorter and recycler to expand on the findings.   Results: Four methods of sorting and the sorting grades/thresholds that are found in the wool recycling industry are outlined, and five methods of recycled blending historically used in the wool recycling industry are established. This knowledge (sorting methods/grades and recycled blending techniques) were applied in practice and from the methods employed, the relationship between sorting in recovery and recycled blending in manufacture was established across three themes: fibre quality, fibre type and fibre colour. Conclusions: The paper concludes that understanding the link sorting and blending provides the foundations for a ‘Design for Sorting’ methodology. When lessons from each theme (quality, type and colour) are combined, this enables fibre value to be retained in recovery and thus, provides a route for longevity of our textile fibres.