Keeping cotton in the loop
What would jeans be without cotton? The natural fibre is literally a staple of the denim industry. The raw material is nonetheless presented by many sustainably minded brands as having negative impacts on the planet’s finite resources, from water to land. Thanks to innovative companies regenerating cotton waste into cellulose pulp and fibres, the mountains of used clothing discarded every day could become an infinite resource to make new materials.
Of all the waste that the apparel industry generates, cotton is arguably one of the more valuable resources to keep out of landfills and incinerators. Demand is high for cotton-rich fabric scraps, deadstock, unsold goods and whatever post-consumer clothes and household linens can be culled from the mounting piles of discarded textiles. These can be shredded down and mechanically recycled into new cotton fibres, or they can be liquified into pulp to make any one of the regenerated cellulose fibres, from viscose to lyocell. While mechanical recycling tends to break down cotton fibres, the process of regenerating their cellulose content creates a new fibre whose properties are akin to virgin manmade cellulosic materials. As the companies investing in these technologies begin to scale up, industrial volumes of these regenerated materials are being made available. A telling sign of a promising future for this new crop of fibres is the launch by Levi’s of its Original 501s in a blend of organic cotton and Circulose, a regenerated cellulose fibre made from cotton pulp by Swedish company Renewcell. This marks a true breakthrough for the company, as “it is truly an iconic product,” says Nora Eslander, Renewcell’s head of communications. With this symbolic achievement, it hopes to convince other major brands to envision replacing cotton, or polyester for that matter, with its circular regenerated cellulose solution.
Renewcell, which was set up in 2012, is far from the only company that is chemically recycling cotton into cellulosic fibres. Since 2017, Austrian manmade cellulose fibre producer Lenzing has been producing Tencel Lyocell with Refibra technology, and progressively increasing the proportion of recycled textile waste. Infinited Fiber Company was established in 2016 to further develop a cellulose carbamate made from textile waste, a research programme initiated by VTT, the Technical Research Institute of Finland. Evrnu, founded in 2014 in Seattle, is yet another company developing a similar technology. It recently raised $15 million to meet surging demand for its fibre regeneration platform called NuCycl. The company says it will use these funds to expand its operations in South Carolina.
Building up production capacity
Renewcell has recently announced that to meet demand for its Circulose pulp, it has decided to double the production capacity of its new plant in Ortviken, some four hours north of Stockholm, from 60,000 to 120,000 tonnes per year.
Located in a former paper pulp processing mill, which closed in 2020, the company will be reusing both the building and the water treatment plant. “The infrastructure is there; we do not need to build a new factory and we have hired staff, experienced workers, who were laid off when the paper mill closed,” says Ms Eslander. A second-hand drying line was acquired, another eco-responsible move by the Swedish company. Its existing facility, located in a former Akzo-Nobel factory in Kristinehamn, in the east of Sweden, produces up to 4,000 tonnes a year of Circulose pulp.
Renewcell has also formed partnerships with traditional manmade cellulose fibre producers to transform its Circulose pulp into fibre. “Sanyou in China is our biggest partner, it processes two-thirds of our production, representing 40,000 tonnes,” says Ms Eslander. Chinese viscose manufacturer Yibin, another partner, has successfully produced a recycled viscose filament made from 100% Circulose. This represents a new achievement as most companies using Renewcell’s pulp most often blend 30% to 50% Circulose with conventional wood pulp.
In Europe, Renewcell signed a letter of intent with German viscose maker Kelheim. “Production has not yet started,” says Dr. Marina Crnoja-Cosic, business development director for Kelheim. “We are in the phase of technical feasibility and optimisation of production.” Kelheim could be one of the first Europe-based companies to turn post-consumer waste into new fibres when operations begin. Lenzing’s Tencel Lyocell with Refibra technology can include post-consumer waste, but its main feedstock is post-industrial cotton.
A large-scale facility is also in the works at Infinited Fiber Company, a €220 million investment. It currently produces its regenerated Infinna-branded fibre from post-consumer textile waste at two pilot facilities, located in two different cities in Finland. “This allows us to produce enough fibre to send sample batches and small commercial batches to our customers, and we are fine-tuning the processes at our pilots so that we can boost output this year and next.
Unfortunately, even with this additional production, we can’t serve everyone,” says Kirsi Terho, Infinited Fiber Company the company’s key account director. The new plant will begin operations in 2024 and will have a capacity of 30,000 tonnes per year. The company has a short-list of possible locations, and will soon be announcing its choice.
The Finnish company also intends to license out its technology. “We are first and foremost a technology company, and licensing our technology is a key part of our strategy,” says Ms Terho. This will enable other fibre producers, such as existing viscose manufacturers, to add Infinna to their product portfolios. “We want Infinna to become a mainstream material as quickly as possible so that it can really make a positive global impact by reducing textile waste and the burden on virgin resources from creating new textile fibres. We can’t do this on our own,” she adds.
Since 2019, Swedish cooperative wood pulp producer Södra has been producing a regenerated cellulose fibre from textile waste it calls OnceMore at its main plant based in Mörrum. Initial research goes back to 2016, with the first lab tests beginning in 2018, says Angeline Elfström, OnceMore’s business development manager. The cooperative structure, with its 52,000 members, may be slower to develop new processes compared to single-focused start-ups, but it has the advantage of an operational mill running 24/7. “We are a small team at OnceMore, but we are backed by a very large organisation,” she says. In its first iterations, OnceMore contained only 3% textile waste, but it now incorporates 20% certified recycled content. “Our target is to reach 50%, and we are moving forward progressively as we want to maintain the same attributes. The material needs to align with industry expectations,” she says. Production capacity is growing steadily, and was increased tenfold to reach 6,000 tonnes last summer.
A well-established wood pulp producer, Södra is a long-standing supplier to many major manmade cellulosic fibre manufacturers. “We are seeing a lot of interest for alternatives to cotton, we feel a real market pull,” says Ms Elfström. Södra and Lenzing came to an agreement in June last year to work together to increase the use of post-consumer textile waste in their processes. The cooperation involves the transfer of knowledge between the two companies with the goal to recycle 25,000 tonnes of textile waste per year by 2025.
Lenzing has been steadily increasing the proportion of recycled content in its Tencel Lyocell with Refibra fibres, going from 20% to 30%, with plans to reach 40% in 2023, and 50% by 2025. The cooperation with Södra will enable Lenzing to broaden the range of suitable materials used to make the Tencel lyocell with Refibra fibres. “We can currently add white cotton/polyester to our sources of raw material with further increase of the raw material base to come,” says Caroline Ledl, head of product management at Lenzing. Lenzing says that more than 90% of the mills exhibiting at Kingpins this April will be presenting fabrics made from Tencel Lyocell with Refibra technology. The group intends to highlight blends with mechanically recycled cotton at the show.
The need to secure waste resources
The companies turning used cotton into cellulose pulp need to secure a constant stream of waste materials, whether pre- or post-consumer, which have a high proportion of cotton, as close, ideally, to 100% as possible. Södra is an exception as its technology separates cotton from cotton/polyester blends. “The polyester is incinerated and used to power the process,” says Ms Elfström.
Up till recently Södra’s process required waste that was either white or light-coloured, supplied by hotels, restaurants and laundries working for the hospitality industry. It has partnered with hotels in UK through the Textile Services Association (TSA), a trade association for the textile care services industry. “We need volumes, not just 100 kg here and another 100 kg there,” says Ms Elfström. “If we were to use household waste, we would need a partner that collects and sorts it, like paper.”
Renewcell is seeking to lower the threshold of suitable feedstock to 90% cotton content, which would allow it to accommodate the presence of elastane. It has formed partnerships with used garment collectors, including Bank and Vogue, one of its largest suppliers, and says it has secured 50,000 tonnes of used clothing yearly. Last December, it signed new multi-year purchasing agreements with three European textile sorters, SOEX in Germany, Texaid in Switzerland and Sysav in Sweden. Lenzing says it is working with customers and partners to develop customer specific take back systems.
Infinited Fiber Company is working with suppliers in Finland and abroad to secure its supply of textile waste. It has recently signed an agreement with Lounais-Suomen Jätehuolto (LSJH), a Finnish municipal waste collection company, which, says Ms Terho, is building a processing plant for discarded textiles.
They are all looking forward to the evolution of waste management policies in the European Union. As part of its Green Deal, EU member countries are being asked to implement the separate collection of used household textiles by 2025. Finland has already passed this legislation which will start in 2023. The EU lets each country decide how they will manage this waste, whether it will be the responsibility of municipalities or specially formed organisations. In France, Refashion (formerly known as Eco-TLC) levies a tax on all companies that sell apparel, footwear or home linens in the country. These funds are used to increase waste collection and its recycling. In 2020, the latest figures available, it collected 204,000 tonnes of used goods and received €34.5 million in ‘eco-fees’. Part of these funds are used to finance research into recycling processes. Refashion has distributed €5 million to some 55 projects since its inception 11 years ago.
What’s next?
Backed by EU funding, Infinited Fiber Company launched and heads a research programme known as The New Cotton Project in October 2020. It has rounded up a consortium of 12 companies, from all stages of the recycling supply chain, and focuses exclusively on post-consumer textile waste. Fashion For Good, based in Amsterdam, is the communications partner.
The project is making good progress, says Paula Sarsama, New Cotton Project coordinator and Infinited Fiber Company product manager. Dutch used clothing collector Frakenhuis and REvolve waste, which tracks waste materials, have mapped the textile waste flows within the EU, and have evaluated available textile streams to identify which are best suited to Infinited Fiber Company’s process. Xamk, the South-Eastern Finland University of Applied Sciences, has refined the pre-treatment process. Spinning partners, Turkey-based Kipas, Slovenia-based Tekstina and Portugal-based Inovafil, have made yarns from regenerated Infinna fibres. These, she says, have been made into fabrics for quality review and dyeing and printing tests. Brand partners adidas and H&M have meanwhile finalised designs, conducted consumer research, and run fabric tests to compare the qualities of Infinna to virgin cotton. The positive results from these tests now enable the consortium to move on to the next step, which is to carry out the process on a larger scale. If all goes as planned, adidas and H&M will be presenting clothing made from regenerated Infinna fibre by the end of the project in 2023.
By then, the new factories at Renewcell and Infinited Fiber, along with expected new production capacities at Kelheim, Lenzing and Södra will no doubt also contribute to building up the availability of manmade cellulosic fibres made from textile waste. The outlook for this chemical recycling method is thus very positive. It is nonetheless very narrow, as it relies on securing high stocks of cotton-rich waste materials.
Lenzing’s Tencel Lyocell with Refibra technology is now a part of the company’s carbon-zero platform. It has a carbon footprint of 2.5 CO2 eq/kg (cradle to gate), and refers to the fibre itself, not to the recycling technology. This data will be added to the Higg MSI, the company says.
Photo: Lenzing
