Known for its rapid production and consumption cycle, the textile industry currently generates between seven and 7.5 million tonnes of textile waste per year in the European Union (EU-27 and Switzerland). This is equivalent to more than 15 kg of textile waste per person per year. As recently indicated in the Mc-
Kinsey report, approximately 85% of this waste comes from clothes and home textiles discarded by end consumers while the remaining 15% originates from textile industries and textile retailers in the form of industrial offcuts and production surpluses.[1]
With regard to the management of post-consumer textile waste, a study carried out in 2022 by EURATEX, the European Apparel and Textile Confederation, reveals that only 33% of post-consumer textile waste is collected separately in Europe, whereas the remaining 67% is incinerated or ends up in landfills around the world. Of the post-consumer textile waste collected, 60% is sorted and separated for sale in second-hand shops while the remaining 40% is sent to recycling streams.[2] In addition, according to the European Environment Agency, more than 1.4 million tonnes of textile waste exported outside the European Union in 2020.[3]
Textile Industry Challenges
All these data on the generation of textile waste and its poor management are aggravated by what is known as fast fashion. Industries design and manufacture fast-paced, low-cost clothing collections in order to follow the latest fashion trends. The industry therefore offers consumers access to newly designed garments at affordable prices on a continuous basis, thus incentivizing the generation of textile waste. When combined with the lack of solid collection systems, this leads to an increase in global incineration and landfill rates.
Recycling processes are also in need of innovation and improvement to cope with the amount of textile waste generated worldwide.
Moreover, the wide variety of composition of today’s textiles (ranging from synthetic polymers such as polyester, polyamide and elastane to natural materials that include cotton, wool and linen) is another factor that hinders their circularity. All this implies the need to develop new separation and sorting technologies to determine the most appropriate destination. Artificial intelligence is now playing a key role in automating this process by making more efficient and accurate sorting possible.
However, uncontrolled production and consumption and the need for separate collection and sorting technologies are not the only critical points in the textile industry. Recycling processes are also in need of innovation and improvement to cope with the amount of textile waste generated worldwide. The complementarity of existing recycling technologies (described below) will play a key role in increasing sustainability in the industry.
European Union Strategies
The above-mentioned data, together with the challenges of the industry, have led the public authorities to launch actions aimed at redirecting the industry towards a more sustainable business model, such as the amendments to the EU Waste Framework Directive. The revision of May 2018, specifically in Article 11, paragraph 1, requires EU Member States to set up separate collection systems for textile waste by January 1, 2025.[4]
In July 2023, the Commission presented new common rules with the aim of making manufacturers responsible for the entire life cycle of textile products and supporting sustainable waste management in the European Union. In other words, the Commission has suggested the implementation of mandatory Extended Producer Responsibility (EPR) systems for textile products in all EU Member States. The aim of this initiative is to accelerate progress in separate collection, sorting, reuse and recycling in line with the EU Strategy for Sustainable and Circular Textiles, adopted in March 2022.[5]
EPR systems have been shown to improve waste management for a variety of products such as packaging, batteries and electrical and electronic devices, where producers bear the costs associated with waste management. Applied to the textile sector, this approach will provide an incentive for producers to reduce waste generation and encourage the circularity of textile products by promoting the design of more sustainable products at source.
But the European Commission is not only focusing on collection systems, but also takes into account the efficiency of sorting, repair, reuse and recycling processes, as set out in Article 9(1) of the revised Framework Directive. This paragraph was amended to encourage the reuse of textile products by promoting repair activities.[4] Furthermore, Article 11, paragraph six now states that the European Commission must consider and establish targets by 31 December 2024 for “preparing for reuse and recycling of separately collected textiles.”
Therefore, the effectiveness and efficiency of sorting and recycling processes are also critical points to be addressed by the industry in order to try to increase recyclability rates of textile waste.
Let’s discuss the textile recycling processes that currently exist and the most promising emerging technologies that technology centres such as AIMPLAS are studying, developing and implementing in the market as innovative solutions for the industry.
Textile Recycling Processes
In the textile industry, there are different recycling technologies that can be applied depending on the type of textile waste stream to be treated. Upstream sorting and separation processes are therefore crucial to ensure good recycling methods.
The different technologies include:
Mechanical Recycling. This technology uses physical forces such as cutting and shredding to convert textiles into usable fibres. After the fibers are obtained, they undergo a spinning process, which involves cleaning, disentangling and arranging the recycled fibers in parallel, then refining and twisting them together to obtain recycled yarn. This is a widespread process in the textile industry characterized by low-energy consumption and high cost-effectiveness. It can be used for all kinds of textile waste depending on the type of material (natural, synthetic or blends), the type of product (e.g. yarns, fabrics, used garments, carpets) and the structure (knitted, woven or non-woven). However, during tearing, cutting and shredding processes, there is a reduction in fiber length of up to approximately 30-40%, which reduces to some extent the quality of the final yarn and limits its use in new textile products. This is a major challenge for these recycling technologies and the industry has addressed them by blending shorter recycled fibres with longer virgin fibres.
Thermo-Mechanical Recycling. This recycling technology uses extrusion processes that combine specific pressure and temperature conditions to melt synthetic textiles such as polyester and polyamide and recover them in pellet form. This process is not suitable for natural fibers such as cotton and wool, or for cellulose-based synthetics such as viscose. Thermo-mechanical recycling is a mature technology that has been implemented on an industrial scale in other sectors such as plastics. However, it is less developed for the textile industry. Energy consumption is relatively low, and these technologies produce higher quality materials than those obtained using the mechanical processes described above. Nonetheless, for textile waste to be recycled and processed using these technologies, input waste requirements are very strict. The composition must be at least 99% mono-material or ensure 99% compatibility
between polymers when processing a multi-material textile.
For example, in the OCEANETS project[6] (coordinated by AIMPLAS in collaboration with the Universidad de Vigo, the Port of Vigo Fishing Shipowners’ Cooperative (ARVI), ECOALF, SINTEX and Asociación Vertidos Cero and financed by the European Commission’s Executive Agency for Small and Medium-Sized Enterprises and the European Maritime and Fisheries Funds, EASME), these recycling techniques were used to obtain high added value products in the textile industry from fishing nets. The picture shows one of the extruders at the AIMPLAS pilot plants where this kind of operation is carried out.
Thermochemical recycling. Thermochemical recycling includes different recycling technologies depending on the amount of oxygen used in the process. Pyrolysis takes place in the absence of oxygen and is used mainly to obtain pyrolysis oil, which can be used as a fuel and also refined to obtain new raw materials with high added value. Pyrolysis it is more consolidated at industrial level in other industries such as plastic waste. Waste that contains oxygen in its chemical structure decreases the quality of
pyrolysis oil, which is why these technologies are not so widespread in the textile industry due to the abundant presence of polyester, polyamides and elastanes.
With controlled amounts of oxygen, gasification is used to produce synthesis gas (syngas) through the partial oxidation of polymers. Recovered virgin-quality syngas is mainly used to obtain substances of industrial interest such as methanol, ammonia, synthetic fuels, oxo alcohols for plasticizers, and adhesives. Thermochemical recycling is a basic technology used on a commercial scale. However, this technology must be adapted or developed for treating textile waste the way it is done in pyrolysis processes. In this case, the input stream can be even more varied, as there are fewer restrictions on the amount of oxygen present in the chemical structure of the waste. The picture shows the pyrolysis and gasification equipment at the AIMPLAS pilot plant, where research is being carried out to bring these technologies more in line with the textile sector and other industries.
Chemical Recycling. Chemical recycling involves a wide variety of technologies and its main purpose is to break polymer chains and use solvents to recover the initial monomers. These techniques are known as solvolysis. Depending on the type of solvent used, they are referred to as glycolysis, hydrolysis and methanolysis, etc. Chemical recycling processes require more energy than mechanical recycling but have the basic advantage of producing higher quality fibers with properties nearly identical to those of virgin fibers. To obtain chemically recycled fibers, the monomers obtained during the process must first be repolymerized. These technologies are selective for synthetic condensation polymers (e.g., polyester, polyamides and polyurethanes), so they can be applied to multi-material fabrics for depolymerization and to separate the other components not susceptible to these techniques.
AIMPLAS is developing different projects in this line, such as the Textended Project,[7] where it is responsible for research into the recycling of textile waste using solvolysis processes, including industrial textile products and polymer blends such as polyester/polyurethane. In fact, it is also working on activities to ensure that recycled products obtained from the textile industry are used. Textended is an EU-funded project coordinated by the VTT Technical Research Centre of Finland. The picture shows AIMPLAS pilot plant reactors, where chemical recycling processes involving solvolysis are carried out.
Physical or dissolution recycling. Although solvents are also used in these recycling techniques, unlike the case of chemical recycling technologies, the polymer chain is not broken to recover the initial monomers. In this case, dissolution processes are applied for the recovery of textile components in polymer form (in polymeric materials) or in pulp form (in cellulose materials). The latter is known as the pulping process and allows cotton to be recovered in the form of cellulose so it can be recycled as viscose.
These dissolution technologies can also be applied to dissolve the polymers that make up fabrics and to extract the adhesives that hold the different layers of multilayer technical textiles together. This produces delamination and separation of the layers (which are usually of different composition to offer specific technical properties to the final fabric), thus allowing them to be recycled individually and increasing process efficiency and effectiveness. This type of operation is carried out in the reactors shown in the above picture.
Dissolution processes can also be used to remove contaminants and dyes from textile waste. Along these lines, AIMPLAS is developing dye-removal methods within the CISUTAC Project.[8] This European project is coordinated by the CENTEXBEL VKC, Research Institute in Belgium, which aims to remove current bottlenecks to increase textile circularity in Europe. The aim is to minimize the industry’s total environmental impact by developing large-scale, sustainable, innovative, and inclusive European value chains. This will be achieved through the development of three pilots focusing on: digital repair and dismantling, new recycling processes, and changes in industry and customer behaviors.
Research and development of new recycling technologies is necessary to treat more waste, regardless of its complexity. It is therefore urgent to address textile waste management and specific challenges of the industry. Actions must also be taken by the European Union, such as those outlined in this article, to promote a more sustainable business model.
References:
1 https://www.mckinsey.com/industries/retail/our-insights/scaling-textile-recycling-in-europe-
turning-waste-into-value
2 https://euratex.eu/wp-content/uploads/EURATEX_FactsKey_Figures_2022rev-1.pdf
3 https://www.eea.europa.eu/publications/eu-exports-of-used-textiles
4 https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32008L0098
5 https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52022DC0141
6 https://oceanets.eu/
7 https://textended.eu/about/
8 https://www.cisutac.eu/
