Technologies for sorting end of life textiles

This report provides a technical and economic evaluation of technological options available for sorting end of life textiles.

The UK industry that reprocesses discarded clothing and household textiles is facing the combined challenges of rising costs and falling demand. At the same time, environmental pressures are placing expectation to recycle ever larger quantities of waste textiles.

Against this background, WRAP commissioned this study to evaluate whether technology exists that could be used to assist in sorting of end-of-life textiles and to evaluate how the technology might affect the economics of the recycling operation.

This report explores whether technology can be used to increase the fraction of discarded clothing and household textiles that are reprocessed in a financially viable way. A technical and economic assessment identified four candidates:

  • manual sorting, the current method;
  • fourier transform infra-red spectroscopy (FTIR);
  • radio frequency identification (RFID) tags; and
  • 2D bar codes.

Each technology was reviewed with the impacts and benefits across five key stakeholders (the manufacturer, logistics chain, retailer, consumer and reprocessor) along with a technological and economic assessment.

Manual sorting of textiles operates successfully, but at a small profit margin because sorting criteria are not aligned with the markets for recyclates. FTIR can only sort by fibre type and colour, limiting its applicability. RFID tags and 2D bar codes can sort by any level of description that can be encoded. Economic models suggest the capital and running costs of sorting by RFID and 2D bar codes could be easily recouped through reduced operating costs and by targeting higher value markets for recyclates once the proportion of marked textiles in the waste stream is very high.

None of the technologies is yet developed to the point of being usable for this application. FTIR works only for a very restricted range of colours and fibre types, while low cost RFID tags will not survive the laundry cycle and tag readers able to interrogate tags on single items in a batch have not yet been developed. Bar code labels that remain readable at the textile’s end of life are currently unproven, but can probably be developed without major investment.