Opportunities and Challenges for the Sorting of Post-consumer Textile Waste

Recently, the rise of fast fashion (FF) has created considerable more post-consumer textile waste (PCTW) in our municipal waste streams across the globe. Most consumers consider FF clothing and accessories as lower quality, and they will likely to dispose the products within a few seasons. During the past 20 years, the number of manufacturing companies associated with the textile industry and the average annual consumption of textile products have doubled globally. However, the generation characteristics and recycling behaviors of these end-of-life clothing are poorly understood by the scientific community. Proper PCTW management requires accurate description of both waste quantity and composition. Given their heterogeneous nature, the reusability and recyclability of PCTW are difficult to assess. Various blends of synthetic and natural fibers, plastics, metals, dyes, and adhesives are commonly used in a given piece of garment. Manual sorting of PCTW is typically required due to the drastic differences in clothing manufacturing process, fabric composition, cleanliness, and conditions. On the other hand, manual sorting requires specific training to sorters and is generally time consuming and expensive. The objectives of this study are to (i) review various textile sorting techniques on sorting of PCTW and (ii) examine the similarities and differences of the adopted methods and technologies. Data is collected from both scientific and gray literature. Keyword searches on various database are conducted, including Web of Science, Scopus, and Google Scholar. Preliminary findings suggest that Fourier transform infrared region (FTIR), near-infrared spectroscopy (NIR), and radio frequency identification (RFID) technologies are commonly adopted by researchers. The characteristics of the sorting methods are compared and examined considering technical, operational, and economical aspects.