Sustainable Textile Processing

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Sustainable Textile Processing: Precision Spray Technology for Better Quality and Less Environmental Impact

As the world pushes to cut down CO₂ emissions, the textile industry is adapting new technologies to improve sustainability without sacrificing quality. In this webinar, we’ll introduce WEKO and RotaSpray’s latest spray finishing and dyeing technology, emphasising the PS2 process, which is specially designed for denim yarn and cotton fabric dyeing together with other kind of spray dyeing processes.

Lucy Mulcahy-Waind
Hi everyone and welcome to today's webinar. Sustainable textile processing, precision Spray Technology for a better quality and less environmental impact, sponsored by WEKO. In this webinar, we'll introduce WEKO and rotor sprays, latest spray finishing and dyeing technology, emphasizing the PS two process, which is specifically designed for denim yarn and cotton fabric dyeing together and other kind of spray dyeing processes. Our speaker today, Jayanta Sanyal, who is head of technical sales and processes for the textile industry at WEKO, has more than 25 years of experience in operations of denim fabric manufacturing and management. Just a little housekeeping before we start today. If you have any questions during the presentation, please type them in the Q A box in your control control panel, and we'll respond to these at the end of the presentation. And with that, we will open today's webinar over to you. Jayanta,

Jayanta Sanyal
yeah, thank you. Thank you. Lucy. Good afternoon, good morning. Depending on the global area, to ladies and gentlemen together towards a more sustainable textile industry. This is our slogan from WEKO and rotor spray. Let's start today's webinar on the topic of sustainable textile processing, precision Spray Technology for better quality and less environmental impact. My company, what white man and conduct is having an experience of 70 years, more than 70 years, with 140 employees, high quality German manufacturing. ISO 9001 2015 certified company, and we took over rotor spray in the year of 2021, this is 100% family owned company, which is a medium sized and in the second generation. At this moment, Mr. Whiteman is the managing partner, and Mr. Shore is the managing director. We have our production sites in Germany, one that means it is in Stuttgart region and Germany too, which is in the very nice black forest region. And we also have in Brazil, another production unit and sales and sub service subsidiaries are in WEKO, UK, WEKO, Italy, vehicle North America. And we call Latin America, around 6500 installation of WEKO fluid application system across the world, which is not only textile, it's, it's, there a lot of other type of industries, like paper printing, tissue, plastic film, batteries, non oven, wood panel, boards, composite and we are also producing, from the Beginning, the powder spraying system for printing paper printing plastic films and foils and glass industries. We have more than 70 1000s of installation worldwide now, since this webinar is based on textile then we concentrate on textile manufacturing. So global textile industry is one of the longest and most complicated industrial chain in manufacturing sector. It involves natural and synthetic fibers, which is agriculture industry or chemical industry, machineries, dyes and chemicals. Apparel industries, retail and service sectors, waste management and treatment, a very big chain of the step by step production process, global carbon dioxide emission figure and the projection for textile and apparel industry in 2020 we Have this figure from European Union, where European Union has projected that per person in one year, how many is the contribution of land, water and raw materials? Which we can see that 400 square meter of land, 391 kilo of. Raw materials, and nine meter cube of water is required per person, even though 2020, was a COVID year. So we can consider that the consumption was much lower than standard, normal years, and carbon dioxide carbon footprint is was per person, 270 kilo, which is in line like we can see that from 2019 to 2030, the in million metric tons of carbon dioxide emission, how it is gradually going up. And this figure is also supporting the projected CAGR of textile market growth of 7.6% till 2030 so what is now our responsibility as not only as a technical Experts as as well as a manufacturer, a user, and also as a individual human being, minimum use of resources, which is raw material, energy, water, dyes and chemicals, waste and pollution reduction, less, less waste production and drainage, use of renewable energies, eco friendly chemicals and dyes, and the most important thing is rethinking the production steps and create a new smart process and products. Our traditional process is deep and deep for the chemical application, which can be finishing or dying or auxiliary application, something like that. The character is of characteristics of deep and deep application. It is 100% penetration, flexible in chemicals, simple cleaning and easy to use. And that's the reason why this technology is so much popular, even today. But there are a lot of concerns low process speed due to very high pickup. Normally, it varies between 50 to 130% depending on the type of fabric. If it is compact, woven, it is oven fabric. It's a neat fabric. It's a single just fabric this. This varies, and normally for a very good quality of padding, Mangle, the pressure cannot go more than five to six bars, so you cannot reduce further the the pickup percentage from the fabric very high dry energy cost because of a lot of water to evaporate, high auxiliary consumption because of the full penetration tailing and set aside variation potential, no possibility of single side application, which is becoming more and more popular nowadays, no different application per side is possible. More dilute recipe, more water uses in the recipe manufacturing, because we know that we have to have this amount of pickup. So the recipe is always dilute longer down time due to batch and lot change. So in competition, the flexible, portable and sustainable application method is rotor spray, non contact, dying and finishing chemical application system here you can see that these are the rotary disc and roto disc is rotating, and the spray is forming from there and is going to the fabric. So production characteristic is contact, free application, so we are not touching the fabric, no telling. Center side variation or substantivity issue, because whatever is spread is going to the fabric. Adjustable penetration, which you can see in the right side photo, that, depending on our parameter setting, we can go on the surface, or gradually we can go inside, up to the complete penetration, like a pattern. Bucha, single passage technology means single side or both side, different effect or same effect, we can generate low pickup, therefore low drying energy, enabling high speed production, fast batch and lot changeover, easy to use and excellent reproducibility. So the whole theme and steps as working principle equipments and process working principle rotary atomizers, which is this one, roto disc or rotary atomizers. These are in competition with dipping and squeezing. His role, technology, home application, vacuum systems, knife coating nozzle or ultrasonic and over pressure atomizer. So everybody, all the technology is having a target for the wellness or good thing for the society to use less amount of energy. We are concentrating on rotary atomizer because our technology, we tested in different way, and we found that this is one of the very trustable, sustainable process.

Now, what is rotary admin, so here is the disc, and all at the center of the disc, nearly pressureless liquid is speeding. And at the age, which is a flux age of the spread is the liquid filament pinches off in the close up range of the efflux edge and creates micro droplets. The target is a equal drop size distribution is the main target for this. So these micro droplets would be the equal drop size. This is very, very important in this process. Now, how this actually looks in this video, you can see that the rotor, disk, rotary and the liquid filament are forming here, which is running with a certain kinetic energy and going towards the material which is to be dyed or finished. Next step is the equipment. So there are different equipments at this moment, Waco and rotor spray is offering to the market. The oldest one is waco sigma, which is used for moisture management, softening, functional spray finishing. These are generally installed in on sunford machine or on stenter, compacting, lying calendar, pitching line, pestilence streamer, all these type of machines work or take is a capsulated, encapsulated system, where the hazardous chemicals for different type of application, like the silver chemistry, copper chemistry, Otis, this type of chemistry, when it is used, then the encapsulation is very, very important. And this normally work protect is used in front of standard coating line and also in non oven lines. Waco Neo is also another encapsulated system with the option of exhaustion. This is basically, this was produced for the denim yarn dyeing, but nowadays this is also used in pad, Steam, pad, dry and also in front of the standard rotor spray is mainly designed for the dyeing application. This can also be used for different finishing application, but this is more popular for the dyeing application. So sulfa VAT, reactive pigment, Indigo dyeing process in slasher dyeing of the denim range, and together with that, it can also be installed in stenter pad, steam pad, dry dyeing ranges also now we already covered the working principles, equipment, and now we are coming to the process. So where WEKO is present right now, outdoor sportswear, workwear, denim, Terry, travel carpets, home textile, technical textile, apparel, textile, and also non open. So we have different type of finishing application, the most common and popular one hand fill modification, that means softening, dye fixation, reactive sulfur VAT over dyeing or tinting. So ability, improver, easy care, finish resin and flat finish soil, repellent, hydrophobic, hydrophilic, then anti static, anti microbial, antiviral and many more. The main ah requirement is that the chemistry needs to be water based chemistry. It has to go to either in water dispersion or in water solution. And the maximum viscosity range for sprayable liquid is 100 milli pascal second application we have. Temporizing for pre moistening before going to the rubber belt to ensure a good shrinkage, compacting, re moistening. Calendaring, a pre moistened calendaring effect is much more shinier than a dry calendar phase two streamer. This has been developed a process of reducing urea for reactive printing, because urea once as humectant. If we want to reduce the urea content, then we have to give a little bit of water before it is going inside the phase two steamer in the back side of the printed side, so that the fabric is having the water. And this can be reducing the heavily the urea content, standard film for functional finishing and re moistening, relaxed dryer, chemical or moisture application before relaxed dryer, coating line, where single side applications are possible, a Row 24 tumbler, which can reduce the water application to increase the drying efficiency. So instead of a padding of the fabric, a much lower quantity of water can be applied with or without some functional chemicals, and the drying capacity can be doubled, or can be increased by three times, singing both a single side application for flame inhibitor for knitted fabric. So if normally knitted fabric, if it is bio polished, then we have some processing problem. If it is singed, then most of the cases, there are certain fabric which is which are very much prone for taking the flames. So if we can spray water with a certain pressure, then this water is eliminating or inhibiting the film, flame generation, raising and pitching limited moisture application is required. This is increasing the pliability between the fibers and reducing the loss of fabric strength. So here are certain photos where we can see that where the Waco is is installed before the sulfur rising rubber belt, or where it is in the reactive printing one phase, like raising and pitching. Here, it's a real example for a cashmere and wool denim company. And normally this is a standard configuration of a center where WEKO is installed above the pattern. Usually one pattern is pickup is between 65 to 70% per woman, and 65 to 110 120 130 for the needs and with the minimal application technology, the pickup percentage is 20 to 25% you can see that there is a 18% polyurethane application is happening in an industry where the polyurethane is getting applied on the front face of adenine fabric. And if the polyurethane can be tinted with some pigments to change the glossiness and as well as of the the tone of the fabric in the front side. Now, how to install so in a normal center frame we are retrofitting, instead of the second pattern, we place the Waco sigma, or waco protect for the both side application. So first pattern will be used for the padding, for the water application, for leveling, and second pattern will be bypassed, and the both side application of Waco will come in place. Here is a real photo. How is waco sigma looks when it is installed at the entry of a stator. So this is giving a benefit of less downtime by favorite color change, because we are not touching the fabric. So color by color, we can run. The solution is not getting got dominated less downtime on recipe change, because normal practice is to stop the machine, to drain it, to make the new recipe and to feed. If our chemical composition is same, depending on the different GSM, we can just increase or decrease the amount. Amount of application depending of the need of the fabric. Sorry, less chemistry use, less water use, which is you can consider 20 to 55% and less drying energy use per meter of fabric. These datas are coming from the actual production data from our customer.

We have some examples in customer side where we were softening a green 155 GSM single jersey. Need where, where we the customer was using two pattern process at 35 meter per minute speed with eight chamber Center, which we change to 42 meter per minute speed, because this is wet on weight, we cannot increase much and the better one pickup remain the same. But pattern two pickup, we reduce from 20% to 12% so there is a reduction of, say, increase of 20% of the production speed, 40% chemical reduction and 20% dying energy reduction per meter of the fabric. Another example is 290 GSM fish. This is also weight on weight finish. We increase the speed from 19 to 25 and 22% pickup was reduced to 15% pickup to match the hand feel. Where we can see there is a direct improvement, or direct gain of 32% in speed and the chemical reduction. Now, when we do wet on dry, somebody also say, dry on wet. So this wet on dry application, the the wet application over a dry fabric where we are using only waco instead of any provider, so there is no downtime required for fabric color change less or no identity downtime on recipe change less chemistry use, less water use and less drying energy Use you we can increase, if the fabric permits, we can double the speed. We can increase the speed 70 to 80% also, depending on the nature of the fabric is the fabric needs a heat setting or a thermal fixation. Then the scope is limited. Otherwise, the 70 or 80% pickup can easily be reduced to 25 to 35% pickup, so the water content is less than half, so the speed increase can be doubled, or even more than double. We have a example of a wet on dry finish on a hydrophobic and hydrophilic treatment of 110 GSM cotton fabric, the normal procedure was padded two runs, standard frame plus coding line. So the customer was doing a coating line for the hydrophobic and hydrophilic they were using the standard frame. So we ran only one time in the standard frame, and this is directly resulting 42.8% of the speed increase and 59.2% of the peak up decrease. So and we achieved a ATCC, 22 result, 100 now you can see that this is an example of a polyester black cotton fabric. This is the back side of the fabric where the everything is going in the fabric. And this is the front side of the fabric where we applied only one side through a carbon. And the result is like this, while in our research lab, we do time to time different type of research. And there you can see I am only doing the test, and this is the result of the one side application of hydrophobic and this is a non pseudo hydrophobic chemistry we applied in this fabric. Now let's come to the dyeing application. We have different type of dyeing application possible. You can see a lot of colors here in on fabric, and we can see a lot of yarns at different colors, different dye. Stuff now, classical fabric and yarn dye, denim yarn dyeing, we have sulfur spray dyeing. PS two, reactive dyeing. PSV 35 reactive dyeing. PS two, VAT dyeing, Indigo spray dyeing, pigment spray dyeing, chemical oxygen. Or color fixation. So we can apply, or we are applying in the following process, dyeing and over dyeing, single side of both side application surface or full body dyeing space or E card dyeing, salt and paper dyeing, more easy shading. And also this can be generating a laser friendly Ring, ring dying effect, which is very important for the denim producer and for the denim market, a rotor spray, rota diet. We say rota diet win because it it is composing with two units. The first one unit, we are giving four spray, and the other unit, we are giving four another spray. So if you see the entry of the fabric, it is coming from here, going like this. So this side is getting one spray this side, one spray this side, and then second, third spray and fourth spray. Then the fabric is inversing here, and the other side is getting, again, four spray. So total eight, number of spray is applying on the fabric, which gradually the density of the color is changing from this phase to this phase when it is coming out from the rotor twin units for yarn dyeing, we have following benefits. We have the yarn dying means the denim yarn dying slasher denim, young dyeing, so eliminating big dye baths and the drainage cost effective production of the small size nowadays, there is a big demand in each company for the small lots Otis and also for the development required in a long slasher line. If we are making these developments, or if we are producing very small length for a particular customer, we are making loss. So here in our technology, this is possible to make as small production as well as small development. Even 500 meter or less than 500 meter is okay, minimal yarn waste, so no need to run the whole line. We can buy a bypass the whole line and can use only the rotor at Twin. I will show you another schematic diagram where it can be very easily understandable, extremely fast job to job changeover and color change, highest flexibility in the dyeing process. New dyeing effect directly on slasher you can see this, this garment, this effect is done only directly on slasher dyeing machine. No washing requirement, no stone wash, no scrapping is required for this reduced washing and laser friendly ring dyeing effect. These two fabric, you can see they are reactive dyed, and you can see their reactive diet fabric is very easily faded by the laser effect. This is a slasher dying range where we have eight to 10 baths of the Indigo together with the pre wedding washing and after post Indigo washing. We can also have a steamer and also the Sky Zone. So the machine length is very high, and usually 400 to 600 meter of yarn is going in the machine, which is responsible for the drainage of 8000 to 12,000 liter of dye bath, or to store 8000 liter to 10,000 liter of the dye bath, depending on different percentage shade. Now in our case, these six to eight times dipping and hearing. In our case, we do only two to four times spray, then earring and steaming. Maximum, uh, diver volume is 130 liters. How we retrofit. So this is a traditional slasher dying range we retrofit here. And this is one of the recommended place, because in this place, if we can do the topping, we can do the color dazzing as well as we can do the Indigo. So this is the recommended place. So rotor twin and steamer followed by a sky in June. Indigo dyeing is still in technological study because we have done some. Indigo dyeing customers has also done the Indigo dyeing. But till now, we have a achieved until maximum 3.5% shade for very light count, and 2.4% Indigo for a standard denim bottoms count, which is between, say, seven to 11.

And this is done with only two rota rota spray. So we are now working still how to increase or improve the color yield. And this the technology is like this that we spray first after the first prey, it looks like this. Then it goes to a festival streamer, where it converts into parotio. Then is gradually converting from brown to finally to this blue color. The most popular thing is to have the rotor spray, as I explained, which is only 120 to 103 30 liter of dye bath is required. Which, if you want to drain, you can drain after the end of the dye lot, instead of 600 to 1500 liter. And we can save one washing box and whole machine. As I said in the beginning, that if we only work here, we don't need to run through this. We can go directly bypass from the top, coming here, we reduce the pickup, and then we go directly inside the rotor dioto In unit. And this is reducing the raw material uses to a very, very high extent. Multi Color topping is also possible when two, ah, non compatible dye stuff is applied at two different side of the yarn, which is not possible of mixing both the dye stuff because of the compatibility problem. One exhaust fast, one exhaust at different temperature compared to the other, or different pH compared to other. Then here we can spray from one side, one color and another side, another color. Finally, the color development is happening inside the steamer, and then the color is fixed on the yarn, inside the yarn, or on the surface of the yarn, depending on the requirement. We have some real example of indigo, sulfur and indigo plus sulfur in different companies. Here we can see that what I said that just just by changing the look of the just changing the parameter, the look of the fabric can completely changed at the time of yarn dyeing. So this is a vintage look. You can see the yarn here, and just by changing the parameter in the running machine, we can completely dye the yarn and the fabric. Look will be like this, and how this is actually produced in the companies. So this is the vintage look production which is going and just switching some parameter in the running machine, we can produce like this. So we don't need to change a lot if the customer wants different type of this vintage look that is also possible only we have to store the parameter in our ACP sheet. Now fabric dyeing, fabric dyeing, we have for spray over dyeing in spray, steam wash, oxidation fixation technique here, also in the pad steam range. Instead of padding, we can put the rotor spray, and this will give the benefit of low production, lots production, and also the benefit of no center side variation. And the very first development, we also have waco Neo, which is having a non stop changeover, where we reduce the speed of the production and we can change from one color to other color. But mind it that we don't recommend to change from a dark black to a light yellow. So it has to be from the lighter shade to the darker shade, or lighter color to dark color, all the time, the PS two process, which is the most successful process that rotor spray has developed right until now, normally the PDPs, which is a very common procedure, or common practice for the fabric dyeing, where we do the dyestuff padding. Then it's a hot flow, a huge energy, consuming a very long dryer. And then it can be a continuous line, or it can be a discontinuous line, like pad dry, a separate and pad steam, a separate pad steam washer. It can also be a continuous line. So in that case, pad dry, then pad, steam washing. So this is the whole line. We eliminate this drying zone completely. So what we do? We do pad with the dye pad, pad with the dye stuff, then spray the alkali and then steam and then wash. Actually, we are not touching the fabric. This is the main benefit. So the hydrolysis of the reactive dyeing are very, very minimum in this type of technology, because the dyestuff and alkali is not coming in one bath in at any condition. This is also helping not to do a re exhaustion of the reactive dye from the alkali bath to the fabric. So salt requirement is very, very less for normally, for the dark shade, we use a very little amount of salt. For the light shade, we don't use it in any short so chemistry use is also less. Water use is also less. The main benefit is the reduction of this drying, which is 1000 to 1350 tons of carbon dioxide per year. So in the line diagram, we can see that this is pad, dry pad, steam washing, then drying and then batching. And in our process, this is the pad spray steam washing, drying and this. So if we consider this like this, that for normally, for a standard PDF, PDPs process, it is required around 1440 tons of salt per year for PS two process, dark sheet, it is required only 480 tons of salt. Salt for medium set is only 168 tons of salt. For light set, we remove everything so we can see a 67 to 88% salt reduction for dark to medium shade, and 100% salt reduction for light shade. So we can see this is from a data of one customer where 1331 tons of carbon dioxide was saved in the first year of the production, which is equivalent to 512 cars in one year. In terms of sustainability, this is a big step, and this is our responsibility, how we can save our Mother Earth. These are some real production fabric where we have no salt to low salt, where we can see that how the depth of the shade changed and the amount of salt gradually started from zero salt to a medium quantity of salt, following processes are in technological studies, which is digital print preparation for reactive and pigment pad, spray batch instead of CPB, Indigo dyeing and slasher polyester fabric dyeing with disperse dyes, which is spray, dry, fixed reduction here and polyester fabric dyeing with pigments. The last one is already running in commercial production for a very top sportswear brand, but we still are working on it to make each month more better process than how it is running today. So if you see the integration in the existing center frame, so we need to apply the dye stuff, and then, sorry, the primer in the digital printing preparation on the fabric. And then this can be cured to make the fabric ready for printing. And this can reduce the amount of application of the primer, and can increase the production speed of the standard so have either a higher production rate or lower the drying energy. The bad spray batch is,

is the comprising with this type of configuration where, here is the pattern, here is the sprayer, so we can either pad the dyes and also. Here is which are in red and spray the alkali, or we can pad with the fixation alkali and the spray the liquor. Here we used to do a there is a secret of one pH rule for any customer who is going for this process. We are giving the technology also to them. Usually, we can make a very small production lot per set, which is 300 to 500 meters. The total production process can be reduced to from three shift to two shift, or even less than two shift to increase reproducibility. This is one of the best method, and we can do color over color, just we need to cover this roles with the plastic, plastic, kill more plastic, something like that, so that one color should not go to the fabric of another color. This is our recommendation for the denim producers that potential live cell or model, we need to restrict the tension zone as low as possible so we can consider a tensile live cell, even smaller, like this, that 1p wedding, then a small dry cans. Or it can be higher dryer, or in higher dryer. People can be very surprised at how I air dryer can work in any yarn sheet. But believe me, we have seen European customers who have no dry cans. They are only working with higher dryers. And for cotton, the color denim line. And also, if the Indigo dyeing is fully ah operation, fully in operation, then a whole dyeing range can be reduced to this length, which is red, reducing the yarn length from the machine from 600 meter, five to 600 meter to less than 200 meter. And this will be a great saving in raw material, polyester dying normally, the data is from di star, which is one is to 10 MLR, which we can see a very long dying time with high water uses low batch volume, batch to batch, matching difficulties and high load on effluent treatment Plant. Not going in details too much. I can just say that for 400 kilo of fabric, dyeing in one color from one machine is wasting 414 1400, liters of water, and this is 415 minutes of production time. So the production of 2000 kilo of the fabric of same fabric in same color from one machine is draining 72,000 liters, which is produced in 34.6 hours. If we this process, we have already developed this process is the spray, then a non contact IR or NIR drying, followed by a short stinter, where the fabric has to go in 210 to 220 degree centigrade temperature. Then this can be discontinuous process or continuous process, we need a cooling, and then reduction cleared, and then another drying, and the process is done. Now, if we can see that 2000 kilo of the fabric, if we are running at 40 meter per minute speed, considering 160 GSM at 1.5 meter width, then this is required 10,200 liter of total water, including the consumption and draining and the production can be done in 3.5 hours, which is 80% less water uses and 90% less dying time. So this is a revolution. We have done a couple of experiment with our partner, company dire, and practically, we want to establish this process in any real manufacturing field, we are looking for a partner for this, and once we have a partner, this process or this technology will really, really help the entire polyester dying chain in future. Now. Now this is the not only recommended. This is already established the pigment dyeing process, which we say that this is after spraying on a dry fabric, we can dry in a non contact IR or an IR dryer, followed by a short stenter frame for for for pigment. We don't even need to do any washing for the disperse I have already shown in the previous slide that we need, then reduction, pair washing and all this type of thing after that. Now, the customer that I was mentioning earlier is producing 24/7 this technology for pigment dying using a special chemistry which is sprayable, and is producing the fabric, polyester fabric for the top plant of global sportswear now this is what we see you.

Yes, the future is ours if we try, if we think differently and if we execute. Thank you very much for your time, and I am open now to receive some questions. If some of you are having some question, I will try to reply my best to explain and to fulfill your queries. Thank you very much.

Lucy Mulcahy-Waind
Hi, Jayanta, thank you very much for that presentation. Yes, we have some questions, so let's make let's begin. So the first question, first question we have, was it? Was it tried with nylon dying?

Jayanta Sanyal
Yeah, we tried with nylon dying. But it's a nylon blend, actually, cotton nylon blend. We are running in in customers place in Pakistan, but not 100% nylon. We never died until now.

Lucy Mulcahy-Waind
Thank you. The next question is, in the case of reactive dying, what apparatus is installed to ensure the fixation

Jayanta Sanyal
the reactive dying, the fixation results we have, we are getting a fixation level of, say, three to four and from four to five on dry cocking and wet cocking. And also we have different fixation results available for the reactive fabric dyeing, and also reactive yarn dying. And your question was actually, what? What process or what can you please repeat the question, 

Lucy Mulcahy-Waind
of course, in the case of reactive dyeing, yes, apparatus is installed to ensure the fixation.

Jayanta Sanyal
What apparatus we are not using any apparatus. The technology is explained that reactive dyes are padded and the alkali is spread, or it is vice versa. The fixation is happening inside of the steamer, and there is no possibility of hydrolysis, which is actually responsible for low fastness, because the color is coming out from the fabric or yarn, so that chances are very less so after a washing, even if some amount of unfixed, dry stuff is there that is going so fastness is automatically achieving,

Lucy Mulcahy-Waind
right? Okay, thank you. And we've got another question. In the case of blends, the the attendees are given a. An example, let's say cotton and nylon dye in what will be the procedure? Will it be feasible via a two step diet? Or can we increase the rotor spray from two units to four units?

Jayanta Sanyal
Yeah, this is possible a two step process. Or it can be also done with two units to four units. Brilliant, yeah, and there will be an intermediate drying between these four units.

Lucy Mulcahy-Waind
Thank you very much. Next question, is it possible to use wool and wool blends dyeing? Do you have any experience?

Jayanta Sanyal
Actually, absolutely. I never died any wool, actually, we never died any acid dies till now in our methodology, but we is continuously developing new new new type of dying technology, dying technique, dying possibilities. So acid dyes are already in our thinking, and we will be in future, trying with this wool and silk dyeing also in our application method.

Lucy Mulcahy-Waind
Fantastic. Thank you. And the next question is, what are the sustainability aspects of spray, dyeing and finishing of the conventional, conventional processes? 

Jayanta Sanyal
In my entire presentation, I have explained that sustainability doesn't mean that use of organic cotton or recycled polyester, and that's it. Sustainability means how we can use less resources. We can reduce the wastage, we can reduce the water uses, and we can reduce the carbon dioxide generation. So in the minimal application technology, the main concept is how we can get the good result by applying less. So when we are applying less, we are using every resources in a less amount. So less amount of resource using is a big step towards the sustainability and wasting less is also a big step for sustainability. Like i i have shown the the global graph that how with the increase in population and with the increase of expected increase of income per capita. So that means GDP per capita, the graph of carbon dioxide emission, is gradually going up, so now we have to target it, and we have to work to reduce the carbon dioxide emission.

Lucy Mulcahy-Waind
Well, thank you very much. We've got another presentation, another question, are there any limitations on fabric weights, construction and blended fabric composition, blended

Jayanta Sanyal
craft, fabric composition, obviously, there is. There are restrictions, like at this moment, in terms of needs, if it is having a lot of Lycra or elastin, where the fabric is turning. We are still not able to dry you die uniformly because of the turning of the selvage. But we are developing a technology where we can guide the salvage and can spray evenly on that. So this is a little bit limitation at this moment for need. So we are successful in warp knit, or say ribs interlock fabric, but we are not successful for single jersey or for for the high stretch material. This is one aspect I can say another thing is that if we have a lot of combination which is not which cannot be dyed in one class of dyes, or a special type of mixture class of dyes, then it's impossible that some some component is taking reactive, some component is acid, and some component is taking the dispersed dying. Then in this process, we are still limited. We cannot do

Lucy Mulcahy-Waind
thank you. And then we've got one more question. In the case of the pre reduced Indigo dyeing, is it only yarns that are dyed, or can fabrics be dyed? How is the skein different from traditional methodology?

Jayanta Sanyal
The Indigo dyeing can be done in two different way. One is a complete Indigo dyeing on the slasher yarn range, which I said the limited. About the percentage shade and the retention of the color. And another one is the I cut, or space dying where we and do this. Dotty dyes with Indigo, which is one of our Indian customer is produced millions of meters for the top European brands in 24/7 and they are really making the rods on the yarn. And this is when this is oven. It is making a completely fashion effect, but they are doing the Indigo dyeing on the yarn. Second thing is that if we can do a fabric dyeing, fabric dyeing, Indigo dyeing on fabric. I think people are trying since decades after decades after decades, never, ever this became successful, and I cannot say that a complete fabric dying is possible with our technology, a fabric with Indigo fabric, oti on surface can be possible with some specific binding system, low visco CD binding system and but fabric dyeing with Indigo, full dyeing is Not possible, but the Dotty dyeing with very less amount of indigo can be achieved, and we already have done it before.

Lucy Mulcahy-Waind
Fantastic. Thank you. And I think that concludes our Q and A for today. Thank you so much, Jayanta for a fantastic presentation. Anyone that is wanting a recording, we will be sending a recording link once this has been uploaded onto w ten.com very soon. And thank you again.

Jayanta Sanyal
And if anybody is having any question, if anybody has an investment plan, any brands who are looking for sustainable sourcing. They can directly contact me in the last slide of my presentation, my email id, my mobile number, everything is given. I can try to help you, support you and always, as I said in the beginning, together towards a more sustainable textile industry, this should be our goal. Thank you very much.

Lucy Mulcahy-Waind
Thank you again. Thank you all.