Colouring with only a hint of water
High-tech solutions that can ‘dye’ fabrics virtually without water promise to cut precious resources by 90% or more. But are traditional wet processes ready for disruption?
From design lab to retail store, colour is a critical component of creativity and a key purchasing trigger for shoppers. It is also a critical pain point in production – to achieve the requested colour consistently. Under such pressure to perform, it can come as a surprise that traditional wet processes used to prepare and dye fabrics have evolved so little over time. The discharge of dyes, up to 30% for reactive dyes on cotton, generates difficult-to-treat wastewater, while variations in shades can lead to wasted bolts of fabric. Tier 2 operations, which cover the processing of yarn into textiles and include dyeing, accounts for 55% of the apparel industry’s greenhouse gas emissions in 2025, reports the Apparel Impact Institute in “Taking Stock of Progress Against the Roadmap to Net Zero”.
The possibility of applying colour with virtually no water and just the right amount of dye using high precision nozzles, plasma, or even digital printing, would significantly reduce water, chemicals and energy consumption in textiles processing. Add in a dash of digital magic, and the desired shades could be more readily achieved, digital passport data included.
A fabric dyed using Xefco’s Ausora equipment. Copyright Xefco.
Endeavour, the near waterless colouring solution developed by Cambridge-based Alchemie, applies colour by ‘jetting’ 1.2 billion droplets of dye per linear metre of fabric. Described as a ‘non-contact digital jet dyeing process’, it was recently tested by Fashion for Good in its Future Forward Factory project that focused specifically on the dyehouse stage of fabric manufacturing. The technical assessment found that Endeavour can reduce water usage by up to 92% compared with jet dyeing and by up to 90% compared with thermosol (or foulard) dyeing. An infrared drying system also eliminates the need for steam, contributing to energy savings of up to 70% compared to jet dyeing and up to 86% compared to thermosol. These numbers are based on real world data captured in a commercial production environment, the company says, which makes the savings all the more impressive.
Radical resource savings
Swedish company imogo has worked on optimising spray dyeing techniques. The Dye-Max operates with a liquor ratio as low as 0.5 litres per kilo of fabric. The technology thus leads to radical savings in water (90%) and energy (90%) needed for fixation. A Dye-Max machine is in operation at Chorka Textile, in Bangladesh, thanks to funding from H&M.
The technology developed by Australia’s Xefco applies colour using plasma, an ionised gas. Its Ausora technology is said to fully eliminate process wastewater and significantly reduce chemicals (by 97%), energy (by 90%) and greenhouse gas emissions (by 94%).
Though technically not a dyeing technique, digital printing is by nature a waterless ‘colouring’ solution offering great freedom in both creativity and production volumes. Kornit’s newest printer, the Presto Max Plus, can apply both 2D and 3D patterns in a one-step process. The only water needed is to clean the conveyor belt, and it is filtered for reuse, Steffen Meiler, global director for sportswear, tells Sportstextiles.
Eliminating wastewater is the real breakthrough for a dyehouse, says Dr Alan Hudd, founder and CEO of Alchemie. A development with a partner mill in Taiwan has allowed the company to achieve zero discharge. The new system first filters oils from scouring and then removes dyes and auxiliaries, generating clean water that can be reused. “Our technology is now a completely clean tech that generates no wastewater,” he says. “This is very relevant in countries like Vietnam and China where permits for new dyehouses are only awarded to companies that are zero discharge.”
Two Endeavour machines are in operation. One is in Taiwan and ‘dyes’ woven fabrics made from synthetic fibres. The other was delivered to Acatel in Portugal earlier this year, and is focusing on colouring knits, of all fibre compositions, natural and synthetic. With both partners, Alchemie has set up jointly-owned dyehouses. “We share the pain, the cost and the profits,” says Dr Hudd of the dye-as-a-service business model.
Xefco can also boast having two of its Ausora machines in operation, one was installed at Shinta Woo Sung (SWS) in Vietnam late last year, and the second in an (unnamed) Indonesian factory in 2026. Xefco has chosen a business model in which it does not charge for the machine, enabled by funding from the Australian government’s Industry Growth Program. It expects to deploy 200 Ausora systems within the next five years.
While plasma has been used to functionalise textile surfaces, few companies have exploited its ability to apply colour. Tom Hussey, Xefco’s co-founder and CEO, initially explored the technology to improve the durability of water-repellent finishes. In the course of his research, he found that atmospheric plasma could also be a waterless alternative to other textile processes. “Colouration became an early priority, driven by both the obvious industry need, and the scale of improvement we could deliver over conventional wet processing,” he says. The company’s head of sales, Timothy Skedzuhn, told Sportstextiles that “the plasma field pulverises the pigment molecules and makes them adhere to a fabric without a fixing agent. There is no need for any precursor chemicals nor for a rinse after colouration”.
Kornit has improved the performance and sustainability of its Presto Max Plus digital printer by adding a layer that is sprayed under the pattern to improve ink fixation, without the need for a pre-treatment. At Texprocess this past April, the company introduced Duratech, a new solution for textile or leather footwear uppers. “This special finish protects the printed pattern and the three-dimensional details. These are the result of our XDi technology which adds an ‘extra dimension’ and can be used to create stiffer sections to offer various functional, elastic or rigid, features. The breakthrough is to offer a complete one-step solution,” says Mr Meiler, who points out that this is particularly useful in footwear that is often made from a complex mix of different materials.
Digging into the details
Alchemie and Imogo’s colouring equipment uses conventional dyestuffs, disperse dyes for polyester and reactive ones for cellulosics. At Xefco, “the same pigment chemistry works across synthetic and natural fibres,” says Mr Hussey. For digital printers, each model or brand works with its own cartridges, and Kornit is no different. The company supplies customers with proprietary water-based Neopigment inks that are Bluesign and GOTS approved, and can be applied on any ground. “Our technology is material agnostic,” says Mr Meiler. The pigments can print on natural and synthetic fabrics, including textiles made from PLA and Dyneema.
With regards to speed, digital printing will not be the fastest, but it is also much more than just a colouring solution. Alchemie’s Endeavour runs on average at 35 metres/minute. “On a standard 75-denier polyester fabric, we can achieve 40 or 45 linear metres/minute, but on a 600-denier polyester the average rate will be 25 metres per minute,” says Dr Hudd. Xefco’s Ausora “typically operates at 5 meters/minute and speed is not generally dependent on the type of textile,” says Mr Hussey. Documentation on Imogo’s Dye-Max indicates that it runs at rates spanning 5 to 50 metres/minute.
On the topic of speed, there is the question of whether a single pass will ‘colour’ both sides of a fabric or not. Xefco has found that dye penetration using plasma is “fairly high”, suggesting that both sides will be ‘dyed’ in a single go. The company is however working on a double-sided system for thicker fabrics. Alchemie’s partner mill in Taiwan ‘jets’ each side of a woven fabric in two passes. Dr Hudd expects that the hydrophilic nature of cotton may make it possible to dye the fabric throughout in one go.
Digital tools
These advanced devices are already fully digital, and this gives them a clear advantage over traditional ‘analogue’ dyeing processes. Technicians in dyehouses spend time testing materials in the lab before finding the right recipe. To remove this experimental phase, Alchemie has added a digital colour matching system that uses artificial intelligence and a database of shades to identify the closest colour.
In addition to streamlining product development, their digital nature makes them ready for sustainability reporting and product passports. “We also see our solution as contributing to shifting the globalisation trend by making it possible to produce locally,” says Dr Hudd. This principle is a key asset of digital printing, as Mr Meiler at Kornit, points out: “Our message is that our printers help shorten lead times, can match demand and reduce overproduction in the apparel and footwear sectors, and allow near shoring.”
While digital printing has grown significantly these past years, not only in apparel but also in footwear, the new waterless colouring techniques have been slower to come to market. A key barrier is no doubt the initial investment, which has been overcome only when costs are shared between supply chain partners. DyeCoo went bankrupt despite support from major customers. Finally, there is also the role that wet processes play in a fabric’s hand feel. Some believe dry technologies cannot achieve the same touch, without adding in a softener. Or an extra rinse.
Photo: Digital printing is overwhelmingly used on sports shoes with textile uppers. Here an example of a matching running kit by Kornit.
