Sustainable Innovations in Coloration
Dr K S Murthy (Pidilite Industries Limited) gives his personal review of the SDC EC National Conference, which took place on 6th June 2014 at the Textile Committee Auditorium, Mumbai, India.
The Chairman Mr Ullhas Nimkar welcomed the audience and briefed them about SDC activities and the theme of sustainable textiles which has been growing in importance. A paradigm shift of industry from the West to Asia, mainly India and China, has resulted in a decrease in European production and hence it has become necessary to address the new challenges through sustainability initiatives and develop new standards for test methods. Challenges are dynamic and changing rapidly including Manufacturing Restricted Chemical Substances (MRSL) just launched by Zero Discharge of Hazardous Chemicals (ZDHC Group). The Indian chemical industry including dyestuffs and finishing chemicals has to comply with this because textiles contribute to exports from India.
Mr Nimkar concluded with the announcement of the next SDC India event on “Cleaner and Greener Textile Processing”, a symphony of machinery and chemicals on 20th February 2015 in Mumbai with globally reputed speakers, leading brands and participation by the entire textile and apparel supply chain.
Chief Guest Mrs Kiran Soni Gupta, Textile Commissioner, Ministry of Textiles, Government of India congratulated SDC India for its decade old efforts and the current initiative to deliberate on sustainable solutions. She spoke on colour and its impact on health and environment, changing consumer preferences, export and import restrictions, and the need for testing laboratories.
The earth’s resources are limited and with the advent of synthetic dyes and synthetic textiles, the challenge is coloration besides value addition with different industries. Mrs Gupta hoped that the deliberations would look into various options and said that researchers on colour, academia and industry should come together to see that the colorants are used constructively in a sustainable manner to retain, preserve and conserve natural resources for future generations. She added that SDC’s efforts in this direction would create a milestone for the textile processing industry.
The Keynote Address was made by Prof M D Teli. He said that the current global population of 7 billion would become 9 billion by 2050 with a consequent increase in consumption of clothing and food. Water demand is predicted to increase by 55% worldwide. Carbon dioxide emissions by 2040 would lead to an increase in global temperature by 2ᵒC.
Sustainable Value Framework Hart and Milstein indicates that serious players in the textile business should adopt the latest technology, decrease the cost of production by continuous processing and be conscious about utilities for production and also the workforce and good governance etc. They have to look at core competence and human relations in a sustainable way.
Profit, planet and people model: Economical, environmental and social performances have to be well balanced. Companies follow environmental laws. The cost involved in common effluent treatment is taken into consideration since it is inevitable.
Ethics at the core of business is a must for unless one is ethically committed one cannot be socially and environmentally compliant. Human development is an ethical commitment.
Sustainability is to be taken as the business model for a competitive edge. A study at the University of Exeter indicates that products which are sustainable are preferred in the market. Profit @2% is to be used for Corporate Social Responsibility. Social accountability, occupational health and safety standards are to be maintained.
Sustainable Apparel Coalition: International body of 5 different countries discussed the Higg Index, a sustainability measurement tool for the industry’s supply chain. More than 350 companies including Indian companies are part of the SAC. At any level, the spirit of sustainability has to percolate downstream, upstream and sideways.
Prof Teli spoke on Innovation in Coloration and the sustainability edge that Plasma desizing has over conventional methods. Ultrasonic energy which brings down quantum of thermal energy and hence is sustainable and a good substitute; Bioscouring using a combination of enzymes like pectinase, protease, cellulose and lipase as a one shot chemical to prepare the fabric for dyeing; Desizing-Scouring-Bleaching in one bath using amyloglucosidate and pectinase and glucose oxidation with hydrogen peroxide produced in situ.
Polyfunctional dyes: Vat dyes are expensive for the coloration of cellulose and reactive dyes have the edge with high and medium exhaustion. Developments are tri reactive and tetra functional dyes with high reactivity, least effluent load, low salt and less TDS. For sustainability, they have low colour in the effluent and also salt due to high reactivity and exhaustion.
Simultaneous dyeing and finishing: sustainable solutions for coloration – Acid dyeing of cotton and resin finishing is done in one bath with energy saving and continuous production. Dyes containing in-built antibacterial property are used for dyeing silk. Some of the dyes are modified to replace CH3 to CF3 for water repellence. Super Critical Carbon dioxide and AirDye technology can be used without water for the application of colour to textiles. The latter uses up to 95% less water and up to 86% less energy, contributing 84% less to global warming.
In the area of printing he spoke on germinated food grains used for extracting starches and for developing superabsorbent thickeners, synthetic thickeners replacing oil-in-water emulsion etc. Digital and Ink jet printing, despite high fixed costs have enormous advantages like less water requirement and unique designs.
Message: Prof Teli concluded that while we try to make our life colourful, we should not strip the colour from the life of future generations and be responsible in what we produce and consume. Sustainability is the hallmark of that journey and innovation may be the torchlight.
Panel Discussion 1: Moderator Dr S Y Kamat – Innovations needed for Textiles
Panellists: Dr (Ms) M M Hundekar (Software); Mr Sumit Gupta (GOTS representative in India); Dr Ashok Athalye (Atul Limited); Mr Ketan Gandhi (L.N. Chemical Industries) and Prof P V Kadole (DKTE).
Innovation spotlight: Tough challenges and innovative solutions – why Indian companies are not living up to innovation; whether NGOs compel the industry to innovate; does industry care for the health of the consumers and environment; can innovation be taught in schools, colleges and universities? Is there scope for innovation with textiles for improving human well-being like durability of fabrics in washing, self-cleaning? Suggestions to make Indian companies innovative leaders in textiles and role of marketing.
Innovation in business is for profit, cost reduction, competitive advantage, as a game-changer. It is need centric and driven by users’ requirements and demands. From the dyestuff manufacturer’s point of view, the need emerges with the cost of raw materials or intermediates eg in the case of reactive dyes, availability and cost of H-Acid is causing concern.
The mindset towards regulation is a barrier for innovation; survival in business sustaining market share rather than doing new things; regulatory bodies impose specific requirements in terms of gaseous emission, liquid effluent and solid waste generation. Fashion design and trends change frequently, which is not sustainable. Refashioning and up-cycling is a concept whereby the existing garment is converted into a new product and this innovation can provide a solution eg Khadi in Indian fashion industry. Consumer education is important as well as industry awareness in conjunction with consumers, trade organisations and brands. An example of innovation in terms of zero liquid discharge is the southern textile sector which uses natural evaporators. Innovation to become successful should be backed by total value chain.
Panel Discussion 2: Moderator Mr C N Sivaramakrishnan – Sustainability in Textiles, Present and Future.
Panellists – Mr Prasad Pant (NimkarTek Technical Services Private Ltd); Dr D Saravanan (Bannari Amman Institute of Technology); Mr C N Guruprasad (Benninger India Ltd).
Sustainability is a ubiquitous and ongoing process. Environment factor is kg of waste per kg of finished product arising due to complex molecules, multistage reactions, water etc. Textile mass balance must be zero with inputs like cotton or synthetic material and fabric output. Sustainability as key perspective, the basic principles encompass ecological, social and economic sustainability. It is resource management of chemicals, water and fabric and the inputs volatilise either into air, water, sludge or retained on finished article. Brands and eco labels are looking at this holistic view rather than in isolation like finished article and consumer safety.
Several certifying bodies which address the issue of sustainability like Textile Exchange, Blue Sign, GOTS, Carbon Neutral etc besides Sustainable Apparel Coalition, the Higg Index, how one would justify sustainability of value chain, brand requirement and perception etc.
Owing to variable perceptions, it is advisable that academicians, industry bodies, testing laboratories, services for certification come together so that standards, procedures and accreditation come on to one platform.
Collaborative steps of academicians and industry on applied research transform it into the shop floor. They implement sustainability measures in textiles. It takes time to implement such measures in the teaching and learning process. Research is done to improve sustainability practices in the industry; sustainable processing methods like desizing, scouring, bleaching using combination of enzymes without chemicals and combine all the preparatory processes into single stage and reusability of process liquor (80% reactivity is maintained). This method was adapted in desizing, scouring and biopolishing.
Interaction with industry: subcycling in which waste gets value added products besides productivity improvement, economy and profitability. Plasma processing technology is promoted for obtaining uniformity in finishing. Research undertaken is interdisciplinary in nature eg enzyme processing involves researchers from different departments like biotechnology and chemistry and plasma technology with physics. Improving the life of jute bags using sugar packing is addressed with the help of chemistry, biotechnology and textiles. Nanotechnology is used to enhance the life of textile products, which is a sustainable measure. Sustainability may appear expensive but the processing of textile industry like by-product and using it in different applications may turn out to be profitable eg spinning mills generate fibrous waste, which is consumed by surgical cotton industry; unspinnable carding waste containing broken seeds or fibre fragments is converted into bio-fuel or mixed with regular fuel.
Sustainability from machinery manufacturers’ point of view: whither supercritical carbon dioxide gaining ground with 4 machines installed. Waterless technology and by reducing water and steam to ensure that product comes out with less impact on environment. One needs to talk about textile chemistry, understand engineering and develop machines and methods to ensure impact on environment.
Sustainability measures involve some trade off. Supercritical carbon dioxide dyeing entails high pressure CO2 and safety; zero liquid discharge is 100% water recycling, establish multistage evaporators for recovering salt and energy consumption and saving of water. Missing links in sustainability are making the entire operations sustainable. The supply chain has to be involved; develop dyes chemistry that can be used in relevant machinery operations which calls for coordination among stakeholders. Sustainability is not in part or isolation but in totality.
Technical Presentation – Between the panel discussions, seven technical papers were presented which focused on innovation.
- Denim Processing – Manish Basle (DyStar India Private Ltd)
Fibre, yarn, weaving and wet processing including the application of indigo and analytic associated with it. Dyeing efficiency as regards costing, effluent treatment and recycling wash water up to 90% and reuse, zero discharge and saving of energy. Finishing by coating system for desired handle and gloss. Future is foam with minimal application technique, Rota spray etc.
- Textile Specialty Chemicals – Raj Verghese (Archroma India Private Ltd)
One Way Calculator is a software calculation tool incorporating data of 300 chemicals, ecological parameters which helps to design processes, cost, consumption, carbon dioxide generation and COD and BOD values besides 15 retailer standards. For sustainability edge, it involves process, fabric, machine parameters, after treatment, effluent load and saving on water and energy. Areas of resource optimisation, advance denim and blue magic to save water, cut short process, less effluent, alternate chemistry, chlorine free technology and metal free nylon dyes.
- Reactive Dyeing – Ajay Kanwar (Huntsman Textile Effects)
Product manufacture in a compliant manner is important for the sustainability of the industry. Brands and retailers are seeking the support from suppliers for stability going forward. Innovations are in the areas of sustainability by reduction in utilities like water or energy or time duration for processing and yet another area is new benchmark for fastness performance. 30% more production per day is obtained by using right technology. While utilities are at the same level, production is much more than overall cost of production resulting in saving. Consumption of water is as low as in continuous dyeing with the range of products used. Water and steam consumption is less since the dyeing of cotton and washing off is at 60ºC due to high fixation (95%). Problems of mills and brands with solutions were cited.
- Coloration of Synthetics – Dr Pankaj Desai (Colourtex Industries Ltd)
One can dye fabric with no water – CO2 emission, energy (40% less than conventional), no chemicals or additives and no waste generation and such dyeing is done with super critical carbon dioxide. CO2 is non toxic, non flammable, sustainable, cheaper and easily achievable in super critical form. Synthetic fabrics can be dyed with modified disperse dyes at 31ºC and 74 bar and its effects help in dissolving the compound and diffusion into fibre. Scouring, dyeing and finishing can be done in a single bath and residual dye is very minimal (0.02%) and can be reused. Basic CO2 dyeing principle, 95% carbon dioxide is recycled and reused and dyed fabric is dried for ready use. Benefits are lower operational cost, processing time (50%) with less redyeing (98% reproducibility) besides level dyeing, brilliancy of shade, fastness properties and no staining of adjacent fibres. Safety aspect – dark shade at 250 bar in automated controlled, designed and engineered machine (any leakage trigger auto shut down), Life Cycle Analysis (benchmark Jet dyeing 2003, Best Available Technology 2010) of super critical fluid was studied at professional level. Key advantages are elimination of water, wastewater discharge and treatment, reduction in manpower. Clipping from Dyecoo exhibited dyeing technology, which is getting established. For yarn and polyamide dyeing machines will be installed in 2014-15; for cotton in 2015 with suitable dyestuff.
- Textile Printing Solutions for Eco Compliance – Ashish Kambli (CHT India Private Ltd)
Different regulations are legal and textile standards of manufacturers’ RSLs. Substance list of 11 restricted is included. Detox campaign of Greenpeace and the target to reach zero discharge of critical substances by 2020. Garment printing and products used like plastisols, water-based and silicones. Acrylic plastisols are PVC free, phthalate softeners are with PVC plastisols with risk of reproductive toxicity. Common solvents are based on phthalates eg DHP and DBP. Plastisol alternatives are water-based dispersions. Water-based products are ecological alternatives that do not contain phthalate. APEO and PVC content is less or zero. Products can be adjusted as per production conditions ie dilution, thickening, retardant, fixing agent, binder, softener and rheological additives. Adjustment of printing parameters ie ink rheology, viscosity for better penetration and soft handle. Curing conditions (time and temperature) are important factors for cross-linking. Pigments may be added up to 20%. Outlook is formaldehyde in the products and on the fabric and its source is fixing agent. Limit on the fabric is 16 ppm (Law 112).
- Sustainable Innovations in Finishing – Arindam Choudhuri (Britacel Silicones Ltd)
Silicones with other finishing chemicals were dealt in an eco-friendly way. Total textile value chain starting from spinner to processor, value chain partner and end marketer. Tie up with company like BEYOND Surface Technologies for textile applications. Polymerise crop oil and use it for manufacturing resin, water repellent chemicals or silicones. They are a provider of innovative technologies, modifying and enhancing textile fabrics and apparels home furnishing and technical textiles. Products marketed are MiDori comprising resin, softener and water repellence (yet to develop). The benefits are to reduce energy consumption, greenhouse gas emission, replacement of conventional finishes and applications. It is sustainable and bio-based starting raw material and cost-effective. Biosoft softener and BioLink resin to replace zero formaldehyde resin and DMDEU. Biotop is durable softener. BioLink is used in denim and Indigo shade appeared bright besides good crease recovery angle, dimensional stability, wash and wear property and wrinkle resistance. Time and temperature should be optimised for curing to get the desired effect and effect of conditions on DP rating. Tensile strength at 180ºC for 60 sec (160ºC for 2 min). Focus is on Green Screen Benchmarks for human health, ecotoxicity and environmental toxicity.
- Machinery for Textile Processing – Sandesh Kashelkar and Deepak Karade (A.T.E. Enterprises Private Ltd).
Innovation is for developing different ideas for improvement, making the process effective, energy saving or quality. Different processes were covered as well as machinery aspects for getting desired results. Sustainability solutions are in the areas of water, air and energy (solar). Osthoff hairiness tester at the end of singeing unit for measuring degree of hairiness; Atmoset SMT 12 (Mahlo) Drum dryer optimisation system for heaviest quality fabrics on vertical drying range with consistent residual moisture and steam saving were touched upon.
SLR Technology – pulsating system ie wave concept to get even dyeing across the package. Continuous dyeing – E control and moist cross-linking MXL process. ER control process benefits are long and short runs with reproducibility, no yellowing, reduced machine contamination and effluent load. PEs/Cellulose blends dyeing by Pad-Dry-Thermosol-Pad-Dry-Pad-Steam and the new E Control T-CA for E Control Thermosol in one step followed by washing.
Resin finishing: Dry cross linking is done to the extent of 90% across the globe, Moist cross linking is 9% and Wet cross linking is 1%. Problems occurring with the processes and solution MXL process using hot flue because E control is alkaline process while MXL is acidic process and advantages like continuous process, shine on fabric surface, smooth handle, excellent dry crease recovery angle and absolutely non-iron.
Air flow dyeing technology (THEN) for cotton, polyester, elastane etc. For polyester the material to liquor ratio is 1:1.2 and for cotton it is 1:4. It is a most efficient machine with reduced liquor ratio and economical machines Nipco HT is a Calendar Wet permeability tester, requirement for high end fabrics like Technical Textiles (parachute fabric and Arvind uses this technology for filter fabrics.
Proposing a Vote of Thanks, Mr Sachin Pulsay, Secretary, Mumbai region thanked the dignitaries, speakers, moderators, panelists and delegates for making the event a success.
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