Textile wet processing Industry is one of the highly water consuming industries, 17-20% of today’s industrial pollution is the result of the textile coloring & treatment, contributing to 72 toxic chemicals in water supplies, 30 of which are permanent. To reduce these water contamination’s, a new technology called as “Air-Dye” has been introduced. The new emerging technology of dyeing is really enthusiastic for textile industries and has reached the international advanced level and has meet the state emission-reduction and energy-saving requirements for environment-protection products. This technology also reduces the effluent load. The system uses 95% less water and 86% less energy than conventional fabric dyeing processes. And while 10% of conventionally-dyed fabric is damaged during the production process, only 1% of Air-Dyed fabrics are damaged no post-treatment or finishing is required. Air Dye process is 2-sided and the hand feel of the finished fabric is luxurious and clean.
Key Words: Air-Dye, Without Water, Techniques, Application’s etc.
Water is used in everything from irrigation to raising livestock, to dying textiles for the clothing we wear. But the textile industry is one of the most villainous sectors when it comes to depleting and polluting fresh water sources. The World Bank estimates that 17-20% of today’s industrial pollution is the result of the textile coloring and treatment, contributing to 72 toxic chemicals in water supplies, 30 of which are permanent . For centuries, water has been the most important element in textile finishing. Today, it constitutes an increasingly expensive medium. Machine GmbH’s Airflow dyeing concept was invented by Wilhelm Christ and subsequently patented in 1978 by then, which produced the first prototype. Over the years, the system was developed further according to the requirements of the industry. Air-Dye technology manages the application of color to textiles without the use of water or with lowest liquor ratio of around 90% lesser than the conventional Dyeing techniques. It was developed and patented by Colorep, a California-based sustainable technology company. Depending on the fabric and type of dyeing Air-Dye uses up to 95% less water and up to 86% less energy contributing 84% less to global warming, according to an independent assessment requested by the company. Air-Dyed fabrics do not leach colors or fade as easily as vat dyed fabrics, because the dye is actually inside the Fibres. The process of making textiles can require several dozen gallons of water for each pound of clothing. The Air-Dye process employs air instead of water to help the dyes penetrate Fibres, a process that uses no water and requires less energy than traditional methods of dyeing.
1.1. What Is Air-Dye?:
Air-Dye technology manages the application of color to textiles without the use of water. It is today’s sustainable alternative to traditional dyeing and decorating processes .
1.2. How Does It Work
Conventional dyeing, such as vat dyeing or cationic dyeing, can produce visually acceptable results. On the down side, it uses polluting chemicals, a huge amount of precious water, and does not provide permanent coloration. Sublimation printing has been used to decorate synthetic textiles, but this process has limited application. Air-Dye technology produces superior results compared to sublimation printing and conventional dyeing, but that is just the beginning of its advantages. Air-Dye technology also reduces detrimental impacts on the environment. because the dye is in the Fibre rather than on the Fibre, bleach and cleaning agents can’t get to it; so colors look richer and last longer. The result is more beautiful colors and maximum color durability, with substantially less water and discharged chemicals.
2. Dyeing – Toxic from the start Until Air-Dye
Four thousand years ago man used water to carry dye to a piece of fabric. Early water pollution was born. Since then, more and more chemicals have been added to color and treat fabric, producing ongoing and ever-worsening water pollution. In the mid-twentieth century, new Fibres such as nylon and polyester were developed. These new “high tech” Fibres were difficult to dye, so even more chemicals were added to water baths to carry the dyes. These chemicals often ended up in the world’s lakes, rivers, and oceans, causing horrific damage. What’s more, traditional dyeing uses an astonishing amount of water. Amounts vary, but coloring fabric can take anywhere from 56 to 600 times the weight of the fabric in water (that’s 7 to 75 gallons of water per pound of fabric). Traditional dyeing pollutes, and it continues to consume vast amounts of the world’s increasingly scarce supply of fresh water. The dyeing of synthetic textiles consumes 2.4 trillion gallons of water a year, enough to fill 3,700,000 Olympic-sized swimming pools. It also uses more than 2.8 trillion mega joules of energy per year, enough to power more than 12 percent of the homes in the United States each year. Finally, textile dyeing produces 568 million metric tons of greenhouse gases (GHG) annually, more than 94 million passenger vehicles emit each year.
Air-Dye technology answer to a 4,000-year-old problem: Air-Dye technology is a revolutionary new way to carry dye to fabric and other mediums. The result is luxuriously brilliant color and a world-changing positive impact on our planet’s energy and water shortage.
3. Air-Dye Technology
Air-Dye operates and licenses patented textile printing machines that color one or both sides of the fabric simultaneously and with independent color control. No water is used in this process and no post-treatment or finishing is required. Unlike traditional heat transfer printing, the Air-Dye process is 2-sided and the hand feel of the finished fabric is luxurious and clean. Unlike rotary screen wet printing, it is possible to independently color each side of the fabric and no water is used in the dyeing or finishing. This process creates new design capabilities, including the ability to contrast (or match) two sides of the same fabric with solids or prints.
Through proprietary software, Air-Dye drives digital and analog printing/dyeing through the interpretation, formulation, and application of color recipes to match the mathematically-objective reflectance curve of the target colors, including tonal and fall-on colors. Rather than working from a “color library” or trying to match “color profiles,” Air-Dye computes color recipes that will reproduce the specified color reflectance curve on a target substrate. Managing color as a reflectance curve across the visible light spectrum, Air-Dye can create a color match under a specific lighting condition, and can even create non metameric color matches. That is, the colors match under any visible light conditions .
3.1. Air Instead Of Water
Airflow was the key element of the technology, as air is an ideal transport medium. The replacement of dye liquor with air as a method of transporting piece goods in jet-dyeing machines was a big step toward reducing water and chemicals consumption. Compared to the jet system in which the nozzles are filled with liquor, nozzle pressure is negligible, thus offering optimum protection of sensitive textile surfaces. At the same time, the use of the mass flow principle provides a major improvement in fabric hank laying, thus preventing creasing.
The moisture-saturated airflow ensures the uniform distribution of temperature on the fabric and in the machine, constituting a prerequisite for even and reproducible dyeing. Moreover, the low level of liquor in the dyeing boiler means the fabric is lighter than in conventional machinery and can therefore be accelerated quickly to high speeds. Thus, the risk of draft or strain is minimal, which is particularly advantageous with regard to the finishing of items containing elastane Fibres .
The high transportation speeds of the fabric result in very short fabric turn time. High heating-up gradients are possible because a very low liquor ratio is maintained. The unique ability to use a hot drain system and rinsing with fresh water in a running wash system considerably reduces the time required for the dyeing process.
The Airflow technology represents the combined result of the entire range of possibilities provided by the technology. Through the interplay of all technical possibilities and functions, economic and ecological advantages over the traditional dyeing technology are achieved. The main advantages are as follows:
♦ Unlimited flexibility with regard to all Fibre – except pure wool – and fabric weight classes between 30 and 800 grams per square meter, as well as all standard market dyestuffs;
♦ The lowest liquor ratio on the market: approximately 1:2 for man-made Fibres and 1:3 to 1:4 for natural Fibres, depending on the article and structure;
♦ Energy savings of up to 40 percent, thanks to a frequency converter, and the use of air as a transport medium, while all other systems need water;
♦ A reduction in the overall process time of approximately 25 percent
♦ Lowest water/wastewater levels .
4. Air-Dye Process Flow Diagram
Conventional dyeing, such as vat dying or cationic dying, can produce good looking results. On the down side, they use polluting heavy metals, a huge amount of precious water and do not provide permanent coloration. Sublimation printing has been used to decorate textiles but is limited in application. Air-Dye advances both . Here are four microscopic photos of the neck section of a dyed synthetic T-shirt:
♦ Standard Sublimation & Heat Transfer Printing: The dye does not completely penetrate the Fibres, therefore, white Fibre may show after cutting or needle penetration are shown in figure-1.
♦ Conventional Dyes: After treatment in a water dye-bath, the Fibres show complete dye penetration. However, color fastness is low to moderate.
♦ Air-Dye Controlled Penetration: Using our proprietary Sibius™ Dyes, penetration is deeper. Colors are richer and colorfastness is better. Penetration control is used with Dye Contrast, Print to Dye, and Print to Print products, including Air-Dye woven.
♦ Air-Dye Complete Penetration: Air-Dye is so advanced that it not only colors the yarn, but also thousands of filaments in each piece of yarn, yielding rich, brilliant colors.
Design: Fabrics dyed with Air-Dye technology supposedly feel no different than conventionally dyed textiles. They can be dyed all one color, a different color on each side, a pattern on one side and a solid color on the other, or a pattern on both sides as follows
♦ Dye-to-Dye Contrast: Air-Dye technology that dyes two different colors on opposite sides of a piece of fabric without the use of water is shown in fig-1.
♦ Dye-to-Print: Air-Dye technology that, on a single piece of fabric, dyes one side a solid color and one side a print, without the use of water is shown in fig-2.
♦ Dye-Squared: Air-Dye technology that dyes the same solid color of ink on both sides of a piece of fabric, without the use of water is shown in fig-3.
♦ Print-to-Print: Air-Dye technology that dyes one side of a piece of fabric with a print and the opposite side of the fabric with another print, without the use of water is shown in fig-4 .
6. Key Features of Air-Dye technology:
♦ Greatly reduces energy requirements, thereby lowering costs and satisfying the strictest standards of global responsibility.
♦ Does not use boilers, screen printing machines, drying ovens, or cleaning and scouring chemicals, thereby eliminating major sources of pollution.
♦ Eliminates water in the color application step and simplifies the process, creating revolutionary possibilities of new industry and employment in un-farmable, arid regions of the world.
♦ Gives consumers a way to choose style and sustainability at a realistic price at the point of purchase, thereby initiating world change.
♦ Environment:- The process of making textiles can require several dozen gallons of water for each pound of clothing, especially during the dyeing process. 2.4 trillion gallons of water are used in synthetic dyeing, Air-Dye’s addressable market each year. Air-Dye technology eliminates hazardous wastewater as a byproduct of dyeing fabric. Water scarcity affects one in three people on every continent and is getting worse as water needs rise with population growth, urbanization and increased usage by households and industries.
♦ Depending on the fabric, and type of dyeing, Air-Dye uses up to 95% less water, and up to 86% less energy, contributing 84% less to global warming, according to an independent assessment. Additionally, some companies state that with Air-Dye technology they can print to order which eliminates production excess and waste.
♦ Economics:- Colorep claims that its Air-Dye Process is priced competitively compared to traditional technology. Additionally, Colorep claims that companies using the technology find the Air-Dye process reduces waste as 10% of traditional, vat-dyed fabric is damaged during the process, whereas with Air-Dye, only 1% is damaged. Colorep also says that Air-Dye enables companies to wait longer to decide what color or print to put onto their fabric, which would reduce the need for apparel makers to guess what colors consumers will want to wear months ahead.
♦ Consumer:- The Air-Dye process manufactures fabric that can be washed at any temperature, with whites or colors, with or without bleach. Because the Air-Dye process injects the dyes in the fabric and not on the fabric, bleach and cleaning agents do not affect them. With Air-Dye, a company estimates for every 25,000 T-shirts sold, the plant will save: Energy:- 1,132,500 mega joules, Water:- 157,500 gallons, Green House Emissions:- 57,500 (Kg CO2 equiv. emissions) By using Air Dyeing amount of fresh gallons of water can be saved instead of traditional dyeing methods are shown in Table-1.
7. Handling Delicate Fabrics
The Airflow Dyeing is being especially suitable for the wet finishing of delicate cellulose and man-made-Fibre knitwear and woven fabrics with a high percentage of elastane. Such fabrics are used in the automotive, lingerie, sports-leisure and swimwear segments. Close attention has also been paid to the achievement of significant savings of precious water and energy resources similar to the Airflow dyeing Techniques.
Extremely safe and gentle product running and outstanding displacement comprise Airflow characteristics. With its concept in machine design, unmatched results in process technology and unparalleled achievements regarding economy and ecology.
The newly designed dome blower ensures that the fabric is transported just by air. This means the liquor actually is used to do what it is meant to do: dyeing only. The liquor ratio is reduced to between 1:2 and 1:5 and provides savings in terms of water and water treatment, chemical, and energy costs. This will bring up to 80-percent savings of liquor compared with costs associated with outdated hydraulic machines, as well as significant savings of time. Shortest cycle times and loading of up to 1,200 meters for lightweight fabrics and up to 200 kilograms for average articles allow high daily production rates.
Polyamide Dyeing: Most of the fabrics for lingerie, swimwear and automotive applications are made of polyamide. That’s why the Air dyeing machine handles fabrics made of 100-percent polyamide with the same results as previously mentioned fabrics. “Current and future trends point towards more and more lightweight fabrics with high contents of elastane in finest yarn counts and gauges .
8. Air Dye Offers exciting new options:
♦ Dye different colors on opposite sides of fabric.
♦ Dye fabric a solid color.
♦ Dye one side a solid color and the opposite side a print.
♦ Dye one side of fabric with a print and the opposite side with another print.
♦ Dye opposite sides of fabric with the same print .
♦ Promotional Items: Banners, retail display / signage, short run branded products, tote bags / reusable bags / aprons.
♦ Apparel: Fabric for all types of garments, finished accessories – scarf / ties / aprons / etc., specialty fabrics for custom items, flags / umbrellas / awnings / tents, uniforms – civic / corporate / medical, swimwear / sarongs, outerwear, sportswear / yoga-wear / active-wear / dance-wear, infant / toddler apparel, junior apparel, missy apparel, wen’s wear, lingerie / intimate apparel / sleep wear, accessories / handbags / cosmetic bags / etc., & shopping bags.
♦ Interiors: Carpet / ceiling tiles, drapes / curtains / blinds, top of bed product – coverlets / bedspreads / etc., linens, wall covering, tabletop / napkins, shower curtains, pillows / mattress coverings, &upholstery – sofas, chairs, etc.
♦ Industrial Print Applications: Hard surface laminate, melamine, Thin paper, vinyl transfer, &thermo films
♦ Medical: cubicle curtains, hospital gown .
The Air-Dye process radically reduces the environmental profile of the color application process while improving the use phase performance of the finished fabric. By removing the requirement of water at the point of color application, Air-Dye technology creates a significant opportunity to localize production for regions of the globe that lack the water resources traditional methods require. Because traditional processes require considerable energy to heat the water and dry the fabric, Air-Dye technology also significantly reduces the energy required at the point of color application. As Air-Dye technology matures, expect to see additional benefits from increased efficiency in power usage, power source, and the direct application of dye without a donor media. Air-Dye is a clear response to an increasing awareness of the environmental impacts associated with traditional dye application processes and a new technology for improving the process of coloration and decoration of textiles.
- http://www.textileworld.com/Issues/2010/March-April/Features/Recent_Developments_In_ Dyeing.
- Coloring Textiles without the Use of Water, New Cloth Market, July 2009.
- Air-Dye Technology: http://www.Air-Dyesolutions.com/products_and_services/products_ and_ services/Air-Dye_technology/
- Deepak Kumar, AmbadasGarje, Kushal Desai, Dharmendra Gupta, Dyeing Without Water, Fibre2Fashion. (www.Fibre2fashion.com).
- Airdye® Environmental Profile Life Cycle Assessment, Prospects, http://www.airdyesolutions.com/uploads/AirDye_EPDv2b_091109.pdf.