Reducing carbon footprints and water consumption through sustainable dyeing and finishing

Sustainability and digitalization in the textile finishing industry are dependent on the level of intensive relationship between the finisher, the machine supplier, chemistry suppliers and other technology providers is crucial to imminent success.

As the textile finishing industry is known for its significant water and energy consumption – there are two elements to saving water and energy – modern plant technology and process optimization.

Innovative approaches are being introduced to reduce water and energy consumption in textile processing to address these challenges. Especially in the recently concluded ITMA 2023 leading exhibitors showcased modern machine concepts with digitalized intelligent control systems that are expressively decreasing the consumption of water, chemicals and energy consumption and the use of these machines leads to a huge drop in environmental footprint compared to older models.

By reducing water usage, optimizing dyeing techniques, and exploring sustainable dyeing solutions, the textile industry can significantly reduce its environmental impact and achieve greater sustainability.

There are several approaches for low carbon and water consumption in textile dyeing and finishing. Some of the approaches are described below:

Table: Some low carbon emission and water consumption techniques.
Methods	Brief Description
Foam dyeing	The main dyeing element in this process is foam, using air instead of water to carry the chemistry or dye onto the fabric.
Air-Dye Technology	It uses hot air to inject dye gas into fibers. Benefits include vibrant, long-lasting colors compared to traditional methods.
Microwave technology	The fabric is washed and put in a container with hot water and dye powder. The container is microwaved, then the dye solution is added and repeated. After filtering, the fabric is dried in shade, but uniform and deep dyeing is difficult, and lots of dye is lost in the rinsing process.
Supercritical Fluid Dyeing	The CO2 dyeing method involves adding dye and fiber to a reaction vessel, pressurizing it with CO2, and maintaining it at high temperature and pressure conditions for 2 hours. Low energy usage, no need for a drying process, no wastewater discharge, and non-toxic supercritical fluids that allow for faster dye diffusion.
Bio-based Dyeing Technology	Bio-based dyeing is a safe, eco-friendly, and cost-effective alternative that uses natural sources like plants, animals, and microbes. Microbe-based dyeing is remarkably efficient and can be done in batch or continuous mode.

The technologies bought in ITMA 2023 for low carbon and water dyeing and finishing are showcased below:

The ‘laundry revolution’

Tonello presented its “Laundry (R) Evolution” at ITMA 2023.Tonello’s all-in-one system for washing incorporates four technologies into a single machine.

• EGO: This technology uses ozone in both water and air to create bleach effects without hazardous chemicals. It reduces water consumption by up to 80% compared to traditional bleaching methods, simplifies wastewater purification operations, and lowers treatment costs.
• NoStone®: NoStone® achieves stone-washed effects without using pumice stone, which has associated environmental impacts. It eliminates the need for a pumice stone supply & thus resets the emissions associated with it to zero. It generates no dust, sludge, or micro-particles and saves water by eliminating specific steps required in traditional stone-washing processes.
• UP: The UP system ensures a continuous and regular water flow inside the machine, which is then recovered and recirculated. This approach reduces the water needed for dyeing and finishing processes, resulting in water and energy savings. The liquor ratio reaches a low level (LR 1:2), and it also reduces energy consumption during the filling and draining times of the machine.
• Core: Core produces a fine mist inside the basket, producing uniform or contrasting effects on garments. This process uses significantly less water than traditional bath application methods, reducing water consumption by up to 96%. It integrates the OBleach process, which achieves authentic bleach effects using ozone instead of harmful chemicals.

Tonello has developed three software programs to optimize its technologies:

• Crea: Simplifies operations and enhances flexibility
• B.O.P.: Enables efficient garment placement and reduces human error
• Metro: Measures laundry consumption and calculates carbon footprint for resource optimization and sustainability.

By combining these technological and software-driven approaches, Tonello aims to make the laundry process more agile, integrated, and truly sustainable, reducing water consumption, energy usage, and the environmental impact of dyeing and finishing operations.

The THEN Smartflow TSF

The THEN Smartflow TSF dyeing machine from Fong’s Europe reduces water and energy consumption through the following features:

1. Smart Fabric Transport System: This system ensures extremely even dyeing of the fabric by accurately controlling the nozzle pressure and pump power by minimizing the need for excessive water usage.
2. Low Liquor Ratio: The machine operates with a low liquor ratio of down to 1:2.5, requiring less water to dye a given amount of fabric compared to traditional dyeing machines.
3. Heat Exchanger: The machine is equipped with a heat exchanger that quickly and efficiently heats the dyeing liquor, reducing energy consumption associated with the heating process.
4. Bath Preparation and Chemical Dosing System: The machine ensures precise dosing of chemicals, dyestuff, and salt, reducing chemical waste and optimizing the dyeing process.
5. Closed Loop Regulation and Digitalized System: The fabric transport system manages fabric movement without a winch, reducing power consumption and minimizing tension on sensitive fabrics.
6. Efficient Control Panel: The control panel allows operators to program and monitor dyeing processes easily, ensuring optimized energy and water usage throughout the dyeing cycle.

Rotor spray minimal application system

The German manufacturers, WEKO and RotaSpray, are exhibiting their rotor spray minimal application systems for textile dyeing, finishing, coating, and moisture management at ITMA.

The conventional continuous dyeing ranges have several problems:

• It consumes high energy & chemicals
• Generates a high load of effluent
•  A cost and scrap-efficient production of small lots is nearly impossible (while the market is increasingly demanding smaller batches)

The companies propose using a minimal rotor spray application method to close the gap in conventional continuous dyeing ranges.

The companies have also developed new processes, such as the PS²-Process (Pad-spray-steam) and PSB35, which offer resource savings and increased efficiency. For example, the PS² process can save up to 1,350 tons of CO₂ emissions annually and reduce start-up scrap rates by 90% compared to traditional processes. These innovations enable the production of smaller batch sizes more cost-effectively.

Additionally, they have developed the WEKO DRY-E and WEKO FIX-E technology, a combination of advanced near-infrared (NIR) light energy and moisture extraction, for continuous polyester disperse and pigment dyeing process. This technology enables fast water evaporation and fixation, reducing drying and fixing times. It also has low total energy consumption and can be easily integrated with renewable energy sources, making it suitable for carbon-neutral production.

CO₂ dyeing technology (DyeOx)

DyeCoo Textile Systems has developed a breakthrough technology for yarn and fabric dyeing using carbon dioxide (CO₂) as the dyeing medium. This eliminates the need for significant water usage and reduces energy consumption associated with the heating and cooling of water in the dyeing process. At ITMA DyeCoo is showcased how its dyeing products work with materials beyond polyester, such as polylactic acid (PLA) and acetate.

Its fourth-generation CO₂ dyeing machines, the DyeOx4, are designed to ensure consistent color penetration and exceptional color fastness in various fabric constructions, including knit fabrics, woven fabrics, and yarn. The machines facilitate a complete water- and chemical-free dyeing process in a single machine, making it efficient and environmentally friendly.

Alchemie Technology

Alchemie’s innovative technologies, Endeavour and Novara, disrupt manufacturing processes that contribute to more than 3% of global CO₂ emissions and 20% of global water pollution. “Our solutions both dramatically reduce the environmental impact and the cost of dyeing and finishing, which has proven to be a compelling combination,” said Alchemie founder and CEO Dr Alan Hudd.  

ENDEAVOUR (Waterless Smart Dyeing)

Endeavour is a new way to dye textiles that saves energy, eliminates wastewater, and reduces costs. It uses a high throughput process to replace five traditional dye baths with just one machine. This technology also allows for dyeing in water-poor regions and reduces environmental pollution. Overall, Endeavour offers 85% energy savings and a 50% cost reduction, making it a profitable and sustainable option for textile coloration.

NOVARA (Digital Textile Finishing)

Novara is a digital textile finishing solution that offers precise coating and digital control of finish location, resulting in cost savings of over 30% compared to pad applications. It also benefits sustainability by reducing chemistry and energy consumption by 30% and 85%, respectively. Novara offers various finish chemistries, including water-repellent and antiviral options, to deliver advanced new functionality combinations.

Everzol ERC reactive dyes

Everlight, a leading expert in chemical technology, is presenting its latest innovation, the Everzol ERC reactive dyes, at ITMA 2023. These dyes offer companies an opportunity to reduce their environmental impact. By utilizing Everzol ERC, businesses can enhance productivity by eliminating process steps and minimizing water and energy usage compared to traditional reactive dyeing methods.

Smart-Indigo

Sedo Engineering, an innovation specialist based in Switzerland, has introduced an innovative dyeing process called Smart-Indigo. Unlike traditional dyeing methods that use toxic chemicals, Smart-Indigo utilizes only electricity and caustic soda to dissolve indigo dyes. This innovative approach –

• Eliminates the generation of toxic wastewater, resulting in significant environmental benefits
• Reduce water consumption by 70%, energy consumption by six times, and carbon emissions by 10 times.

Flexible fabric dyeing machinery

Sclavos has developed a new fabric dyeing machine that they were showcasing at ITMA. The Athena series machine is flexible, produces high-quality dyeing results, and reduces water and energy consumption. It can handle many types of fabrics, including synthetic, elastane blended, and cellulosic materials.

During ITMA 2023, companies demonstrated their dedication to achieving sustainability goals and satisfying the increasing demand for environmentally-friendly products by showcasing solutions that minimize carbon emissions and water usage.