No wood to waste
In addition to going into manmade cellulosic fibres, the renewable resource that is pulped wood is also being tapped for other textile industry supplies, including polymers and chemicals, offering a new array of materials that are not derived from fossil fuels.
For makers of wood-based fibres, nothing is lost. The parts of timber that are not turned into cellulose pulp are commonly used to power the factories that make viscose-family fibres. Now, as the race heats up to find alternatives to petrochemicals, some trailblazing companies are finding other ways to transform this natural and renewable raw material into polymers and chemicals.
Many seek to use only leftover wood. The timber industry, like that of apparel, generates its fair share of waste. “In the US alone, it is 50 million tonnes every year,” says Jane Palmer, founder and CEO of Nature Coatings. For Kristoffer Ekman, co-founder of NordShield, waste is not the proper term: “I wouldn’t talk of waste, as everything is used in forestry.” He sees it as a ‘residue’ that is full of resources, and he is not alone.
From chemicals and pigments
The result of more than a decade of research, the antimicrobial finish that NordShield has developed and patented is drawn from pine tree resin, “a side stream of the forestry industry,” Mr Ekman tells WSA. “Since the early 1980s, the inventor of the process had been looking for a sustainable alternative to biocides. He tested a wide array of substances and found that pine tree resin was a highly effective antimicrobial agent, which has been used in wound-care for ages.” Based in Espoo, Finland, and founded in 2016, the company launched its biobased odour-capturing technology, NordShield Crisp, last year. “It is a non-biocidal, non-leaching, biodegradable and plant-based anti-odour technology,” he says. The finish is said to form a two molecule-thick film on the surface of the textile, and can withstand up to 30 washes. “It is a physical film, but it doesn’t impact hand-feel,” he adds.
In addition to NordShield Crisp, made for cellulose-rich fabrics, the company also offers a citric acid-based antimicrobial for synthetics, NordShield Citex, which is also biobased and biodegradable. “Safe by design is an important principle for us,” says Mr Ekman.
"Consumer awareness is growing, and many mills and brands are switching away from metal-based biocides.” The wood resin-derived finish is in advanced trials at major brands, is already being used by a shoe manufacturer in Asia, and he expects to be able to announce specific collaborations with brands and mills later this year.
Start-up Scandinavian athleisure brand APRí Sportswear launched its first series of products this June, incorporating NordShield Crisp-treated loungewear in a cotton-lyocell blend. Brand co-founder Evelina Boström seeks to make high-quality activewear designed for longevity, which brought her to choose the plant-based anti-odour finish. “It allows users to wash their clothes less often and thus saves energy and water. It reduces their carbon footprint and preserves the garment itself,” says Ms Boström, who describes NordShield’s Crisp as “ground-breaking”.
Nature Coatings has been breaking new ground in the world of pigments with its wood waste-derived BioBlack for nearly ten years now. Made from certified FSC-recycled wood waste, it is a safe, non-toxic and carbon-negative alternative to petrochemical carbon black. Sales are growing, says founder, Jane Palmer, and the company has expanded its distribution network, its product offering (with two dispersions in addition to the pigment) and can now rely on its fully commissioned factory, located in the south-east of the US. “It allows us to control quality and pricing, as we no longer contract out manufacturing. The wood waste comes from within 60 miles (95 kilometres) of the plant, and we make everything under one roof,” she tells WSA. This marks a new stage of development for the company that can now produce hundreds of tonnes per month, she says.
Nature Coatings has set up warehouses and distribution facilities in Portugal, Italy, Turkey, as well as Pakistan and Dubai with its partner iTextiles. Denim has been a big focus for the company, but sportswear and athletic footwear makers also use the black pigment for screen printing, rotary printing and coatings. A new application, as a solution for dope-dyed cellulose yarns, is in trials with a MMCF manufacturer based in India. “This development can be called a match made in heaven,” says Ms Palmer, “as it is a wood-based fibre dyed using a wood waste-derived pigment.”
To polymers and more
The cellulose and lignin content of wood can also supply ingredients for bioplastics and biosynthetics, as some companies have been investigating, with varied results. Origin Materials, based in West Sacramento, has been working on extracting chemicals and polymers from wood waste since 2008, when it was spun off from the University of California, Davis. It went public in 2021, and has a biorefinery running in Sarnia, Canada. But the company’s “biomass conversion technology” has, for now, only been used to make PET caps and closures, first from corn starch and, as of this April, from locally sourced wood residues. This achievement has helped take its share price past the $1 minimum threshold on the Nasdaq exchange.
Origin Materials expects to be able to produce building blocks for polyesters through its CMF (chloromethylfurfural) platform, a chemical that can theoretically be converted into bioMEG, and possibly even bioPTA, to produce a biopolyester. It signed a memorandum of understanding with Indorama Ventures in 2023 and had formed a similar partnership with PrimaLoft two years earlier. Origin has recently licensed a process technology from Dutch company Avantium to convert derivatives from CMF into FDCA (furandicarboxylic acid), a building block for a biopolymer known as PEF (polyethylene furanoate) that Avantium is developing.
UPM Biochemicals, a division of the UPM industrial group, a €10 billion company specialising in wood-derived products, is also seeking to make the building blocks for a biopolyester. It uses a different technology and has already supplied Indorama with its BioPura BioMEG. It has invested €1.1 billion in the construction of a biorefinery in Leuna, Germany. Initially planned to go into service late last year, it should begin operating at the end of 2024. At full capacity, it should produce 220,000 tonnes annually of BioMEG and 'renewable functional fillers' from regionally sourced beechwood. These include renewable biochemicals, including a sustainable alternative to carbon black, David McCann, head of business development, tells WSA. He adds that demand for polymers from the fibre and plastic industries is currently stronger than from other industries.
UPM has been supplying Dyneema, a former DSM company now owned by Cleveland-based Avient, with wood-derived bio-ethylene. German outdoor sportswear brand Vaude presented a fleece jacket last year made from a biopolyester fibre that was polymerised and spun into yarn by Indorama from UPM’s BioPura BioMEG and conventional PTA, and knitted into a fleece fabric by Italian mill Pontetorto.
Speaking at a Performance Days conference in March, Vaude’s head of innovation, René Bethmann, said that this prototype, presented at ispo last year, was “a first milestone” in the use of bioMEG to make a polyester yarn. “The next phase, for us, is to have a bioPTA, which makes up 70% of a polyester fibre,” he told the audience. He suggested that bio-naphtha could be transformed into paraxylene and then terephthalic acid (PTA).
Many start-ups and companies in Scandinavia focus on wood, a key industry for the region, and quite a few seek to develop more sustainable viscose-making processes, seen at TreeToTextile, or invent new fibres, as Spinnova is doing. Founded in 2019, Espoo-based Nordic Bioproducts Group (NPG) aims to make both a low-impact cellulosic fibre and biochemicals and bioplastics from wood. Norratex, the name it has given its MMCF yarn, has been in development since 2022. “Our process is similar to that of viscose but doesn’t use any harmful chemicals. The fibre feels like cotton and drapes like viscose,” says co-founder and CEO, Olli Kähkönen. In his discussions with large fashion retailers, he has found that making fibres from wood was not viewed as favourably as he thought. “This is possibly the result of the work done by Canopy, which we fully support,” he tells WSA, but it signalled to him that wood had lost its lustre as a source of fibre. The start-up has since pivoted to focus on agricultural residues, wheat straw or bagasse, as sources of pulp, and is currently working with major MMCF producers; Mr Kähkönen sees this as a long-term project that could take five or 10 years.
Currently, operations at NPG’s first microcrystalline cellulose (MCC) plant have begun using what it calls AaltoCell Technology, developed at nearby Aalto University by company founder, Dr Olli Dahl. In addition to medical applications (as an excipient), it can also be used in bioplastics. “We can make the ingredients for biodegradable wood-based buttons and accessories for the fashion industry,” says innovation lead, Saara Suurla. Local creative lab, Structural Colour Studio, makes bio-sequins from the company’s cellulose-based biochemicals. The shimmering colours of the sequins are not the result of a dye but of a coating that forms nanostructures that reflect light in various colour frequencies, like butterfly wings or peacock feathers. “Wood waste is an abundant material that can be used to make many non fossil-fuel based materials and chemicals,” points out NPG sales manager, Minna Laitinen.
There is, thus, a wide array of valuable and beautiful textile products that can be made from this type of waste. This is proof that wood residues offer more resources than meets the eye.
APRí Sportswear has just launched with two ranges, one is treated with NordShield’s Crisp wood-derived anti-odour technology, made for cellulose-rich fabrics. The other, polyamide range, uses HeiQ’s mint-based antimicrobial.
CREDIT: APRí Sportswear
