Recycling technologies for enabling sustainability transitions of the fashion industry: status quo and avenues for increasing post-consumer waste recycling

Figures & data

Figure 1. Waste categories in the fashion industry and ease of recyclability.

Table 1. Recycling technologies in the textile industry.

Recycling technologies	Product examples	Advantages	Limitations
Thermal recycling	Energy, heat	No fiber sorting, suitable for all types of waste	Using exhaust-gas treatment, only synthetics have good limiting oxygen index Destroys resources for new garments
Mechanical recycling	Wiping rags, yarns for new fabrics, fabric strips for blankets Nonwovens for insulation mats	All fibers and fiber mixtures Processes readily established Closed and open-loop recycling	Mechanical cutting and ripping of textiles may deteriorate fiber properties High-quality yarns require additional virgin fibers
Thermal-mechanical recycling	Polyester yarns out of Polyester bottles	High-quality fibers and yarns similar to virgin polyester fibers Open-loop recycling	Homogenous fiber inputs Better suited for industrial waste Only few industry-scale processes worldwide
Chemical recycling using chemicals to break up fibers	Cellulosic oligomers and polymers out of worn cotton and other cellulosic fibers, polyester monomers, oligomers out of polyester	High-quality fibers and yarns equivalent to virgin fibers Suitable for closed-loop recycling	Homogenous fiber inputs Better suited for industrial waste Only few industry-scale processes worldwide
Biological recycling using enzymes to break up fibers	Cellulosic oligomers and polymers out of cotton and other cellulosic fibers, polyester monomers, oligomers out of polyester	High-quality fibers and yarns equivalent to virgin fibers Suitable for closed-loop recycling	Homogenous fiber inputs, Better suited for industrial waste Only on laboratory-scale available

Table 2. Description of case studies.

Case study	C1	C2	C3
Headquarters location	Europe	Europe	United States
Type of recycling	Mechanical, thermal-mechanical, chemical	Mechanical	Mechanical
Geographical waste stream	Waste input from Europe, North Americas, Asia; processing in Asia and Europe; new products in Europe and North America	Waste input from Europe; processing in Europe and North Africa, new products in Europe and North Africa	Waste input from Europe; mechanical recycling in Europe, new products in North America, Asia, and Europe
Type of business	Large enterprise	Small- and medium-sized enterprise	Small- and medium-sized enterprise

Table 3. Characterization of interviewed experts.

Experts	Business, business association, research	Knowledge and application: types of recycling	Knowledge and application: geographical coverage
E1	Business: Fashion	Mechanical, thermal-mechanical, chemical	Europe, Asia
E2	Business: Fashion	Mechanical, thermal-mechanical	Europe, Asia
E3	Business: Recycling	Mechanical, thermal-mechanical	Europe, Africa, Asia
E4	Business: Recycling	Mechanical, thermal-mechanical	Europe, Africa
E5	Business: Recycling	Mechanical, chemical	Europe
E6	Business Association	Mechanical, thermal-mechanical	Europe
E7	Business Association	Mechanical, thermal-mechanical, chemical,	Europe
E8	Research Institute	Mechanical, thermal-mechanical, chemical, biological	Europe
E9	Research Institute	Chemical, biological	Europe
E10	Research Institute	Chemical, biological	Europe

Table 4. Challenges and opportunities to increase post-consumer waste recycling.

Building block and organization in value chain	Challenges	Opportunities and possible solutions
Collecting -Professional collectors	Revenue streams require change due to fewer premium secondhand donations and increasing waste Increasing import taxes and bans on secondhand garments Expected increase in shipping prices due to increasingly stricter environmental regulations for logistics	True-cost approach to incorporate environmental impact issues in virgin-fiber price Responsibility of fashion businesses for whole value chain including end-of-life solutions could incorporate garment-price increase that goes to recycling businesses, e.g., per item per weight and recyclability
Collecting -Fashion businesses	Vouchers and stationary collection systems may provide purchase incentive for increased consumption Mailing options increase carbon footprint compared to stationary collection systems	Take-back systems should not provide purchase incentives such as vouchers but instead improve consumer education about recycling
Sorting	Increase in waste accompanied by increase in sorting businesses may lower labor standards	Extended producer responsibility could include labor standards at sorting
	Automatic sorting technologies do not solve pre-sorting for secondhand markets	Pre-sorting by consumers: differentiating between good condition and worn such as differentiating between glass colors in Germany Further development of automatic sorting RFID and QR codes helpful for professional workwear-rental businesses
Recycling	Virgin fibers are too inexpensive	True-cost approach to incorporate environmental impact issues in virgin-fiber price Responsibility of fashion businesses for whole value chain including end-of-life solutions
	rPET from PET bottles diverts resources from packaging industry instead of incentivizing recycling of worn clothes	Commitments to recycling of fashion businesses should include worn garments in order to rethink their designs for recyclability Transparency also in terms of labels whether circularity labels include take back and recycling