Asif Muhammad Sami TECHNOLOGY OF ECO-FRIENDLY TEXTILE PROCESSING- A ROUTE TO SUSTAINABILTY
TECHNOLOGY OF ECO-FRIENDLY TEXTILE PROCESSING- A ROUTE TO SUSTAINABILTY KEYNOTE PRESENTED BY Asif Muhammad Sami BSc. Textile Engg, MBA, CText (ATI), Fellow- IEB, Textile Consultant CEO- EuroAsiatic Resources, Chairman - S S Vision Ltd & Textile Consultant - Perseus Ltd. Cell: 01819213971, email: [email protected] ABSTRACTS: Textile Project like eco-friendly or green project must be designed for sustainable green factory building concept also textile raw materials , dyes & chemicals, textile processes all should be based on 3R (reduce-recyclereuse) concept. The processing of textiles should be cost effective and environment-friendly. Innovative and efficient strategies to achieve these goals are needed. This paper reports various problems in different stages of processing textile materials and their “green solutions” the alternatives by which the problems can be avoided through innovative techniques and various measures of textile cleaner production”(CP) which ensures textile processing “eco-friendly”, “cost effective” and “sustainable business”. ECO FRIENDLY / GREEN TEXTILES CONCEPT The project factory building should be designed on go green concept. Textile raw materials are processed in eco-friendly manner and certified by GOTS etc. Dyes and chemicals should be OKEOTEX certified standard. Textile processing right from Raw fiber, Yarn manufacturing, Weaving/knitting, wet processing, finishing processes all should be maintained using eco- friendly technology. Textile waste water should be treated considering basis of 3R (reduce- recycled & re-use ) concept. ECO- FRIENDLY TEXTILES PROCESSING CONCEPT Textile Cleaner Production (CP) like Water saving, energy savings using all possible methods. Re-use of textile waste, recycled & re-use of waste water, recovering and re-using salt, re-use of waste heat energy. Carbon emission control Environmental sustainability care for the environmentInfluence the supply chain to use sustainable processes/method. Operate business in environmental friendly way. Work to conserve water, energy and reduce / recycle waste. Sustainable design approach – explore the use sustainable materials and products. NEED FOR ECO- FRIENDLY & RECYCLABLE + RE-USABLE TEXTILES: Concerns related to textile industries areTextiles production and processing- chemical intensive applications Associated social and environmental concerns GROWING CONCERNS- Increasing industrial pollution Industrial waste disposal problems Economic and social health of the farmers and industrial workers. Unawareness about socially responsible business structures are required. ENERGY SAVING GREEN FACTORY BUILDING SHED: Using insulation of building walls, floor & ceiling. Replace old windows which are bad thermal insulators. Make the building shell as air tight as possible. Install heat exchange for proper ventilation. Roof of sunny side should use collects solar energy. Heavily frequented door should have automatically closing system. Light from shaded side yields natural light but not heat. New building using geothermal energy exchange. Use of insulation of all steam pipe and wire duct. Using rain water for garden irrigation, technical use or as toilet flash water. WHY WE ALL NEED TO BE CONCERN ABOUT ECOFRIENDLY (GREEN) PROCESSING IN TEXTILES: Textiles /Garment industry is contributing to the global warming & pollution from the stages like Cultivation of the fibres Yarn manufacture Fabric manufacture wet processing Manufacturing of the garment Transportation to customers Usage and disposal STAGE 1: RAW MATERIALS (FIBER) CONTRIBUTORS TO CARBON FOOTPRINT Cotton cultivation requires large amount of pesticides, fertilizers and water. Approximately 257 gallons of water is required for only one tshirt. ECO-FRIENDLY OR GREEN SOLUTIONS: ORGANIC COTTON is “GREEN” fabric. It is grown - where synthetic chemical pesticides, fertilizers and genetically modified organisms are avoided. Organic fertilizers such as Neem or Garlic extract are used. ECO-FRIENDLY OR GREEN SOLUTIONS Substitute cotton for other natural eco- friendly materials like hemp, wool, organic cotton, soy silk, bamboo fabrics ,jute, corn fibre etc having without any harmful effects of chemicals or toxics. Synthetic fabrics such as polyesters are – - Easy care and more durable alternative to natural fabrics. - These are more energy intensive in production, but these fibers need to be washed at lower temperatures thus saving a lot of energy throughout their life cycle. ECO-FRIENDLY OR GREEN SOLUTIONS Cellulose based fibres like viscose can be used. There are now developments of new fibres of natural origin like Tencel (Lyocell) made from wood. EXAMPLES OF SOME ECO-FRIENDLY FIBERS : Organic Cotton, Organic wool, Organic Silk, Organic Jute etc Manmade fibers like corn/Soya bean, Pineapple, Banana leaf, Lyocell Recycled fibers like Recycled Cotton, Recycled Polyester Natural fiber like colored Raw Cotton ORGANIC COTTON – A SUSTAINABLE ALTERNATIVES SOCIAL AND ENVIRONMENTAL BENEFITS Organic Cotton helps in pollution control, improving soil fertility. Organic cotton farming helps in preventing contamination of water, soil & air. Apart from using in all diversified products, organic cotton also suitable for baby products, apparels, hygiene and care products like cotton balls, ear buds, sanitary pads, medical textiles, cosmetics bags etc. RECYCLED COTTON; RECYCLED COTTON is nothing but made from recovered cotton that would otherwise be cast off during either spinning, weaving, knitting or garment cutting process. THE DISCARDED COTTON WASTE from above mentioned process are collected , shredded into small fibers and processed once again into yarns and fabrics in cost effective method. RECYCLED COTTON is also known as eco friendly choice in clothing fashion industry. COTTON WASTE RE-CYCLING PROCESS involves no chemical addition rather it helps in generating employment and better positive impact in the environment (clean production). RECYCLED POLYESTER (PET): Polyester is one the most non-biodegradable polymer which creates environmental problems. Wellman inc. Introduced in 1993 as the first polyester textile fiber made from post consumer pet packaging. Recycled pet is used in diversified products like backpacks and blankets, t-shirts, sportswear, soft luggage and socks etc. Eco friendly recycled pet is certified by OEKOTEX and SGS etc. STAGE 2: YARN FABRICATION AND FABRIC MANUFACTURE Contributors to carbon footprint There are many stages required to process cotton from fibre to fabrics the fibre are cleaned, carded (combed) spun into yarn, coated with starches or chemicals, woven or knitted into fabrics, CONTRIBUTORS TO CARBON FOOTPRINT & GREEN SOLUTION In sizing process , starch is used in sticky paste form to yarn to enhance its strength and its abrasion resistance. The starch paste consists of preservative in order to protect it from the stains get formed on the fabrics surface. Some preservatives like penta-chloro phenol that are toxic effect on human skin, should be avoided by utilizing a synthetic starch decreasing the health hazards. Use oil stain remover during the weaving operations before textile wet process so that oil stains do not get formed. PROCESS INVOLVED FIBRE PREPARATION YARN SPINNING CONTRIBUTION TO POLLUTIONS Fiber waste, Packaging waste, packaging waste, sized yarn, fiber waste, cleaning and processing waste PROCESS INVOLVED CONTRIBUTION TO POLLUTIONS SLASHING/SIZING Fiber lint, yarn waste, unused starch based sizes, water with high level of BOD, COD WEAVING Packaging waste, yarn waste and fabric scraps, used oil. KNITTING Waste yarn and fabric scraps packaging WASTE YARN AND FABRIC SCRAPS PACKAGING Textile processing industry requires huge volume of water , energy & various chemicals for Desizing, Scouring, Mercerization, dyeing, printing and finishing stage. Textile industry, backbone of fashion garments, is large variation in demand of type, pattern & color of fabric resulting into significant fluctuation in waste generation. Textile processing generates much waste steam, including liquid gaseous and solid wastes, some of which may be hazardous. Wet processing creates the highest volume of waste water. Textile finishing represents the most variable area in the production process. A wide and ever-growing range of finishes are now available that either improves the properties, handle or texture of the fabric. TEXTILE WET PROCESSING- VITAL ENVIRONMENTAL ISSUE Some important environmental concerns related to textile wet processing; Intensive chemical based wet processing like scouring, bleaching, mercerizing, dyeing, printing etc Heavy metals like iron, lead, copper etc consist in dyestuffs auxiliaries, binders etc. Residual dyestuffs, chemicals in water: due to poor dye fixation with fiber. PVC and Phathalets: used in Plastisol printing paste and colorant fixatives. Formaldehyde: found in dispersing agents, printing paste and colorant fixatives. Dye effluent-wastewater issue. CONTRIBUTORS TO CARBON FOOTPRINT The conventional preparation process of Desizing, Scouring and Bleaching with their related wash-off stages, produces heavy BOD in effluents. Chlorine used in bleaching creates halogenated organic substances, of which some are suspected to be carcinogenic e.G.., Chloroform thus is not preferred. Use of banned amines and toxic dyes, banned amines are the chemicals which are released from some of the azo dyes on reductive cleavage. These are suspected to be carcinogenic and being banned. Carriers ( disperse dyes) and solvents may be emitted during dyeing operations may lead to volatilization of aqueous CONTRIBUTORS TO CARBON FOOTPRINT hemical emulsions during heat setting, drying or curing process, thus creating harmful volatile organic compounds. Acetic acid and Formaldehyde are two major emissions of concern in textiles. Textile mills usually generate Nitrogen and Sulphur oxides from boilers. Significant sources of air emissions in textile operations -Resin finishing and dyeing operations, printing, fabric preparation and waste water treatment plants hydrocarbons are emitted .These processes can emit formaldehyde, acids, softeners and other volatile compounds. Wool industry used chlorine based compounds for anti-shrinking dealing and such practice also generates toxic effluents. Oxalic Acid is used for removing rust stains before bleaching. The oxalic acid is lethal aquatic organisms and increase COD & BOD to a significant level. TEXTILE PROCESSES SIZING DESIZING CONTRIBUTION TO POLLUTION Penta-chloro phenol as anti mildew agent Voc’s from glycol esters SCOURING Emulsifying agents like nonyl phenyl ethyloxylates, chloroform as scoring assistance. Hypochlorite (chlorine bleaching) products like chlorine dioxide BLEACHING TEXTILE PROCESSES DYEING & PRINTING CONTRIBUTION TO POLLUTIONS Azo dyes containing carcinogenic amines CDFA based on formaldehydes dyes containing heavy metals such as Iron, Zinc etc Formaldehyde as mordant Formaldehyde fixer/binder in pigment printing Formaldehyde as cross linker FINISHING Reactive softener metal fluorides, DDT, and other anti bacterial materials containing metals in rot proofing. Amides like melamine amides in water repellent ECO-FRIENDLY OR GREEN SOLUTIONS: Dyes made from natural pigments and soymilk used as binding agent and sizing agent makes the whole dyeing gentler on the environment. Dyes that forms carcinogenic amines on reduction and thus increase bod/cod need to be avoided. Where possible, use high fastness direct dyes having 90% upto 99% exhaustion rate should be chosen instead of using reactive dyes which having low exhaustion rate 65%-75% to reduce dyeing cost as well as etp running cost. Usage of Hydrol as a substitute of sodium sulphide is recommended for sulphur dyeing. low salt Dyeing process requires more salt for exhaustion. So usage dyes may be used. ECO-FRIENDLY OR GREEN SOLUTIONS: An integrated chemical pre-treatment (single bath process) i.e. Combined Desizing, Scouring, Bleaching is recommended to reduce the water, chemical consumption and also energy. Fabrics to be dyed with deeper shades may not be bleached. In case of dyeing and printing toxic chemicals may be avoided. Formaldehyde free resins and finishing chemicals may be used for finishing. SUSTAINABLE PROCESSING OF TEXTILES: EXPLORE INTO BIO PROCESSING OF TEXTILES Bio-processing can simply be defined as the applicant of living organisms and their components to industrial products and processes, which are mainly based on enzymes. Like Enzymatic Desizing- by using Amylase bacteria. Enzymatic bio scouring ( by using lipase/cellulase enzyme)saves water by 30% and energy upto 60%, less fabric weight loss & strength loss, better fabric quality and enhanced color brightness after dyeing & low TDS in discharge. Enzymatic bleaching – (Catalases/laccases for removal of H2O2) saves water, energy, shorten bleaching process cycle, eco friendly process and consistent bleaching result, saves chemicals. * Bio polishing and Eznymatic based softeners (Cellulase) etcenzymatic bio-finishing yields a cleaner surface, softer hand-feel, reduces pilling and increases luster. EXPLORE INTO BIO PROCESSING OF TEXTILES - BIO-STONE WASHING (DENIM FINISHING) – Using a special cellulase enzyme instead of pumic stones. Cellulase works by loosening the indigo dye on the denim in a process known as ‘bio-stonewashing’. A small dose of enzyme can replace several kilograms of pumice stones. The use of less pumice stones results in less damage to garment, machine and less pumice dust in the laundry environment; in addition, it’s possible to fade denim without risk of damaging the garment. DECOLORIZATION OF DYE HOUSE EFFLUENT BY ENZYME: Laccase enzymse produced from fungi like Trametes Modesta or Trametes Versicolo etc as Fungi are used for dye decolourization in effluent treatment which is major factor for environmental issue. ECO-FRIENDLY OR GREEN SOLUTIONS: ECO-FRIENDLY SUPLHUR DYEING METHOD: Since sulphur dyes as single dyes alone consumption 20%-25% for cotton dyeing in the world. Using eco-friendly thioria di-oxide or indirect cathodic reduction/electrolysis method ( although relative expensive than traditional method) avoiding traditional sodium sulphide can save dyes consumption. ECOFRIENDLY REACTIVE DYEING: Various environmental problems encountered in reacting such as high levels salt & high color concentration ( unfixed dyes) in effluent with huge volume of water consumed.Reactive dyes poor fixation of ranging 10%-40% dyestuff hydrolysed goes down drain which is aesthetically unpleasant, blocks sunlight, algae overpopulate, reduction in o2 levels in water, suffocation of flora and fauna in water courses. Therefore, water effluent treatment plant is now becoming prime consideration by the industry and equally important as the production of textile product itself. ECO-FRIENDLY OR GREEN SOLUTIONS: Significant amount of water consumption, energy consumption, dyeing cost and effluent load can minimized by using either cationic surfactants ( instead of salts) Or dyes with high exhaustion rate 90%-99% ( preferably direct dyes) instead of reactive dyes with low exhaustion rate 60%80%) As a result of being cationic (instead of anionic) pretreated cotton, the number advantages recorded such as: No requirement for salt Nucleophiles in polymer more reactive than hydroxyl roups in fibre. Neutral ph of application Hydrolysis minimised Colour fixation yield maximised Colour fixation yield maximised Less colour in effluent ECO-FRIENDLY OR GREEN SOLUTIONS: Less wash-off requirement Significant reduction in operation time Significant reduction in water consumption DEGREE OF FIXATION OF DIFFERENT DYES ON FIBER ARE FOLLOWS: DYES----------- FIBER----------%FIXATION ----%LOSS IN ETP ACID DYES----POLYAMIDE--- 80-90--------------5.0-- 20.0 BASIC DYES---- ACRYLIC--------- 95-100-------0.0 – 5.0 DIRECT DYES --- CELLULOSE---85 - 99-------1.0 – 15.0 REACTIVE DYES -CELLULOSE-50.0- 85.0----15.0– 50.0 SULPHUR DYES-- CELLULOSE--60.0- 90.0---10.0-- 40.0 DISPERSE DYES --- PES----------90.0–100.0----0.0 –10.0 METAL COMPLEX --- WOOL-------90 – 98 -------2.0 WATER FREE DYEING (SUPERCRITICAL FLUID DYEING): Uses carbon dioxide as the fluid medium on disperse-dyed synthetics, eliminating aqueous effluent. ECO- FRIENDLY EFFLUENT TREATMENT METHOD (BIO TECHNOLGY): Combined biological system with electron- beam or advanced oxidation process (AOP) method or Reverse Osmosis (RO). SCHEMATIC PROCESS FLOW DIAGRAM OF ELOECTRON BEAM METHOD COMBINATION WITH BIOLOGICAL SYSTEM ETP CLEANER PRODUCTION (CP) IN THE TEXTILE WET PROCESSING For sustainable eco-friendly textile processing ,cleaner production in each stage of specially textile wet processing is must. Cleaner production includes: Steam trap maintenance Insulation of un insulated steam and condensate return pipelines Insulation of steam valves, tanks, pumps etc. Re-use flash steam Using boiler economizer Insulated hot water tank with dyeing machine. CLEANER PRODUCTION (CP) IN THE TEXTILE WET PROCESSING Condensate recovery Following right first time (RFT) dyeing method concept. Use multi functional concentrated chemicals and high exhaustion rate dyes reduces effluent problems. Huge water savings – by adopting eliminate water leaks in taps and pipes, use rain water, closed cooling system, continuous dyeing, digital printing, co2 dyeing, reduce washing and rinsing process cycles, Reuse water drained out of steam condensates Minimize washing and rinsing (overflow) operations CLEANER PRODUCTION IN THE TEXTILE WET PROCESSING Reuse of the first wash water from solution preparation tanks Restrain hose pipe use and create a central cut sample washing place. Insulate steam pipes Optimize operation of air compressors and chilling plants Use transparent roofs Reduce spillage of chemicals Use of magnetic device for soft water in boiler. Recover and re- use of waste heat ( using heat exchanger) Co-generation/ tri generation system where ever feasible. Using frequency inverter, peak load management, servo motor where ever applicable, electronic ballast, energy saving lights, Increase fabric to water ratio to 1:6 or even less. Automatic boiler blow down mechanism Recovery & re-use of sodium sulfate using zero discharge etp Improve process control stages to avoid reprocessing Improve trial recipe in laboratory CLEANER PRODUCTION IN THE TEXTILE WET PROCESSING Improve process control stages to avoid reprocessing Improve trial recipe in laboratory Use of magnetic device for soft water in boiler. Recover and re- use of waste heat ( using heat exchanger) Co-generation/ tri generation system where ever feasible. Using frequency inverter, peak load management, servo motor where ever applicable, electronic ballast, energy saving lights, Increase fabric to water ratio to 1:6 or even less. Automatic boiler blow down mechanism Recovery & re-use of sodium sulfate using zero discharge etp Improve process control stages to avoid reprocessing Improve trial recipe in laboratory STAGE 4: GARMENT MANUFACTURING CONTRIBUTORS TO CARBON FOOTPRINT Many processes are involved in garment manufacturing and pollution occurs in each and every stage. 1. In designing department making of prototypes produces garbage’s like fabric scraps, pattern papers stationary items, etc. 2. Production department undertakes spreading, cutting and sewing responsibility. This department generates large amount of waste in form of cardboard boxes, labels, tapes, thread cones, stickers and fabric scraps CONTRIBUTORS TO CARBON FOOTPRINT 3. Finishing department contributes to pollution while the fabric goes various processes like washing, pressing, stain removal, inspection, folding and packing. This consumes water and also some chemicals such as detergents, liquid soap, acetone, amyl, etc. Which are used in washing and stain removal and garbages also produced in packing of materials. 4. Miscellaneous sections include computerised embroidery section, effluent treatment plant, kitchen, canteen, mess and general maintenance which also contribute in pollution. DEPARTMENTS ADMINISTRATIVE DEPARTMENTS DESIGN & LINE DEVELOPMENT DEPERTMENTS CONTRIBUTIONS TO POLLUTIONS Stationary waste, packing waste, etc Packing waste, fabric waste, paper pattern waste, etc yarn waste, packing waste, threads, tapes, fusing rolls, fabric scraps, ploy bags and stickers. Packing waste, chemicals contributing to high bod/cod levels in waste water. Packing waste, fabric scraps and fuel PRODUCTION DEPARTMENT FINISHING DEPARTMENT MISCELLANEOUS DEPARTMENT ECO-FRIENDLY OR GREEN SOLUTIONS Various elements that are used in design i.E, colour, texture, fasteners, fabrics, etc, the components of these should be maintained as a ready data bank. Biodegradable trims should be preferred against synthetic trims e.G., Natural buttons made up of peral, wood, shell, leather, porcelain and bone. Plastic and metal buttons may be avoided. Avoid use of fusible interfacings, which incorporate solvent treated adhesives as solvents like formaldehyde have been classified as unsafe for the environment as per standard given by OEKO-TEX 100. * Use of materials such as heavy metals like chrome, lead, nickel used as fasteners like zippers and buttons are considered unfriendly to environment. Use of large baler bags for storage or supplies especially at fabric store where the fabric is stored in individual poly bags. CAD & CAM system can be used to gain optimum fabric Utilization. Installation of led’s (9w) at the needle points of sewing machines will help to reduce the overall requirements of tube lights in the stitching section. Regular maintenance, lubrication and upkeep of the machine using white oil Mobil oil will result in improvement in efficiency of the machine. Usage of eco-friendly lubricants and stain removers, which are free from chlorinated solvents. Prefer using of eco friendly hang tags that can be hung to the garment by thread rather than using plastic staple or string. * Apparel can be packaged in bio-degradable pvc-free packaging and in 100% recycled cardboard boxes. STEP 5: TRANSPORTATION AND DISTRIBUTION CONTRIBUTION TO POLLUTION Some forms of transportation have more emissions than the others for e.g. Transporting one tonne of goods over a distance of 100 km emits 0.7 kg of CO2 by ship, or 158.0 kg by air. ECO-FRIENDLY OR GREEN SOLUTIONS Use the bus or train rather than car for transporting goods and for travelling purpose. Consider cleaner fuels like ethanol e10 or Bio-diesel which reduces CO2 emission significant amount. STAGE 6: USE OF TEXTILE GOODS AND DISPOSAL CONTRIBUTORS TO CARBON FOOTPRINT More than last two decades clothing has become increasingly affordable for everyone. Retailers and brands have capitalized on this affordability by moving away from summer and winter collection to fresh collections more than last two decades clothing has become increasingly affordable for everyone. ECO-FRIENDLY OR GREEN SOLUTIONS Recycle as much as possible. For example, old fabrics can be used to make wipes or to make quilts, appliqué work. Cellulosic waste fabric can be recycled for making handmade paper. ENVIRONMENTAL SUSTAINABILITY Need to believe in environmental sustainability Implementing incremental steps in supply chain process to accomplish. Need to be aware about the social, economical and ecological benefits of environmentally sustainable product development processes. CONCLUSION: The concept of “eco-friendly designing” products from start to finish has come about. It involves considering the ecological dimension of the entire production process, from the fibre to the finished product, including its manufacturing processes, but also its packaging and labeling, right the way through to recycling & reuse the product at the end of its period following 3R concept. So sustainable green trends in processing of textiles are: Maintaining of high & consistent quality product in cost effective manner. Improved functionality Lower generation of aqueous waste and off- gases Minimum use or reuse of water and chemicals Overall environment friendliness. Reduce water and energy consumption during preparation, coloration and finishing (CP). Improve process efficiency -Reduce exposure to hazardous chemicals QUESTIONS AND ANSWERS ???
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