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Denim washing

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Denim washing

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  1. Denim washing

  2. Prepared By : Prepared By : Mazadul Hasan sheshir ID: 2010000400008 13thBatch (session 2009-2013) Department : Wet Processing Technology Email: mazadulhasan@yahoo.com Blog : www. Textilelab.blogspot.com (visit) Southeast University Department Of Textile Engineering I/A 251,252 Tejgaon Dhaka Bangladesh ©right

  3. What type of Denim wash it is ???

  4. INTRODUCTION Enzyme & bleach are used in denim apparel washing .Acid enzyme & neutral enzyme both are used in denim apparel .Enzyme is more suitable than bleach for environment on the other hand bleach are suitable for production but it’s a hazardous in environment .So enzyme is more popular. Depending on garments construction different types of washing process can be done. 1.Twill/Canvas/Knitted/Corduroy - Normal wash, Pigment wash, Caustic ,Si wash 2.Denim/Jeans/Gabardine - Enzyme wash, Stone wash, Bleach wash , Acid wash 3.Grey fabric- Super white wash

  5. Washing: It is a technology by which outlook, size and fashion of garments are changed or modified is called garment washing. Washing is mainly applied on denim garments and any other casual garments. Purpose of washing:  To remove sizing materials and to soften the garment.  To modify the appearance to make fashion.  To create different effects and finishes.  To create vintage look and used effect.

  6. DENIM WASHING Denim washing is the aesthetic finish given to the denim fabric to enhance the appeal and to provide strength. Dry denim, as opposed to washed denim, is a denim fabric that is not washed after being dyed during its production. Much of the appeal of dry denim lies in the fact that with time the fabric will fade in a manner similar to that which artificially distressed denim attempts to replicate. With dry denim, however, such fading is affected by the body of the person who wears the jeans and the activities of their daily life. This creates what many feel to be a more natural, unique look than pre-distressed denim.

  7. DENIM What is denim ? Denim is a twill-weave woven & 100% cotton fabric that uses different colors for the warp and weft. One color is predominant on the fabric surface. Denim wears well and resists snags and tears. It is available in different weights and is usually made of cotton, although hemp denim is also available. Denim is commonly used for jeans and work clothes, as well as for casings for organic futons and pillows. Characteristics of Denim Fabric      It is for long wearing. It is hard wearing. It is very strong and durable. It resists snags and tears It creases easily. Denim fabric process :- Desizing → Enzyme → Caustic → bleaching → Hypo → Softening → Hydro extractor→ Dryer m/c → Garments Delivery.

  8. DENIM Denim are dye by indiga dye: IndigoBackground Indigo, or indigotin, is a dyestuff originally extracted from the varieties of the indigo and woad plants. Indigo was known throughout the ancient world for its ability to color fabrics a deep blue. Egyptian artifacts suggest that indigo was employed as early as 1600 B.C. and it has been found in Africa, India, Indonesia, and China. The dye imparts a brilliant blue hue to fabric. In the dying process, cotton and linen threads are usually soaked and dried 15-20 times. By comparison, silk threads must be died over 40 times. After dying, the yarn may be sun dried to deepen the color. Indigo is unique in its ability to impart surface color while only partially penetrating fibers. When yarn died with indigo is untwisted, it can be seen that the inner layers remain uncolored. The dye also fades to give a characteristic wom look and for this reason it is commonly used to color denim. Originally extracted from plants, today indigo is synthetically produced on an industrial scale. It is most commonly sold as either a 100% powder or as a 20% solution

  9. Production sequence of Washing Garments receive from sewing ↓ Scraping ↓ Tearing ↓ Whickering ↓ P.P spray ↓ Curing/Tearing ↓ Washing ↓ Drying Hot + cold ↓ Checking ↓ Disposes

  10. DENIM GARMENT WASHING: GARMENT WASHING: The technology which is used to modify the appearance, out look comfort ability & fashion of the garments is called garment washing. Since 1978, garments pre washing has become more and more popular. It began with denim jeans for the following reasons, 1. Before garments pre washing was done on jeans, consumers had to wash them at home before wearing them because before washing they were too stiff, too long and too big to wear. 2. After pre washing, the consumers do not have to worry about the fit after they wash them as pre washing has taken away almost all the shrinkage and made the jeans stable. 3. After pre washing the denim color looks more lively particular with the pronounced washed look left on the double needled seams.

  11. DENIM WASHES ARE OF TWO TYPES Mechanical washes 1. Stone wash 2. Micro-sanding Chemical washes 1. Denim bleaching 2. Enzyme wash 3. Acid wash

  12. TYPES OF DENIM WASHES TYPES OF WET WASH PROCESS: 1. Normal wash/ garments wash/ rinse wash. 2. Pigment wash. 3. Caustic wash. 4. Silicon wash. 5. Stone wash. 6. Enzyme wash. 7. Stone Enzyme wash. 8. Acid wash. 9. Bleach wash. 10. Tinting wash TYPES OF DRY WASH PROCESS: 1. Sand Blasting. 2. Hands scraping. 3. Over all wrinkles. 4. Permanent wrinkle. 5. Grinding &Destroy. 6. Broken & tagging. 7. P P Spray & P P Sponging. 8. Etc.

  13. TYPE OF MACHINE USED IN WASHING PLANT: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Submersible Pump 11. Grinding Machine 12. Tagging Machine 13. Steam chamber for crinkle 14. E.T.P (Effluent Treatment Plant) 15. Generator 16. Sand Blasting Gun 17. Sand Blasting chamber 18. Spray gun and dummy 19. Screw compressor 20. Laser draw Sample washing Machine (Horizontal / Vertical Type) Washing Machine (Side loading) Washing Machine (Front loading) Hydro extractor Machine Dryer Machine (Steam) Dryer Machine (Gas) Chemical Mixture Machine Industrial Oven (Gas/Electric) Boiler

  14. TYPES OF CHEMICAL USE IN WASHING PLANT: 1. Enzyme 2. Detergent 3. Acetic Acid 4. Anti-stain 5.Bleaching powder 6.Sodium hyposulfite 7. Caustic Soda 8. Soda Ash 9. Sodium Bicarbonate 10. potassium Permanganate 11. cationic/nonionic Flax softener 12. Micro Emulsion Silicon 13. Salt (sodium chloride) 14. Buffer 15. Hydrogen peroxide 16. Stabilizer 17. Fixing 18. Catanizer 19. Optical Brightener 20. Resin 21. Sodium Metabisulphite 22. Desizing agent

  15. Some Washing Chemical List Desizing Agent : DesizingHts, D-Peast Anti Back Stain Agent : Antistain – Lp-30 Fastness Improvers For Dyeing : Albafix® Levelling Agents For Dyeing : Albatex® Fastness Improvers For Dyeing : Albafix® Enzyme : G Enzyme S89, G Enzyme – Sl, InnozymeNpe S89 Salt : G/Salt. Alkali : Naso4 Ph Control : Using Buffer & Acid Bleaching Agent : Sodium Hypochlorite Naocl; 15% Cl2 Available Calcium Hypochlorite. Neutralizing Agent : Hydro Peroxide, Bisulphate OrThiosulphate. Softener : Innosoft 1070

  16. Function of Chemicals used on denims 1. Bleach fast Indigo     Value addition to denim Retains indigo on certain parts Kind of resist effect Chemical applied by brush, cured at 150ºC Ex. Indigofix AXN 2. Anti-depositing agent    Prevents “back staining” of fabric by loose indigo during washing Improves contrast in denim Used in stone wash step 3. Dye stuffs with softener  To carry dyeing and softening in one step  Soft and supple hand  Saves time, money and energy as added to final rinse  Gives used and worn out effect

  17. Function of Chemicals used on denims 4. Anti creasing agent  Provides fabric to fabric lubrication  Prevents formation of crack marks and streaks  Minimizes abrasion and gives strength 5. Wrinkle formation  Creating smooth and permanent wrinkle  Cross linking concept Ex. DMDHEU  White pigment  Can be applied by brush, spray or screen  Then cured at 150ºC  Washed and treated with softener 6. White pigment  Can be applied by brush, spray or screen  Then cured at 150ºC  Washed and treated with softener.

  18. CHEMICAL WASHES

  19. A Typical Denim Garments Washing Process: Garments received from sewing room / section is subjected to following process: 1. Batching, 2. Desizeing, 3. Enzyme/stone wash treatment, 4. Decolonization, (Bleach wash or Acid wash) 5. Finishing

  20. Desizing: 1. Batching: Garments are often turned inside out first; this is a very time- consuming labor oriented task. Garments are weighted in a suitable wt. as per m/c capacity. Desizing: Mainly it is done to remove the water insoluble starch from the fabric of garments as well as it gives a degree of absorbency & soft handfeel to the garments. There are three methods of desizing. 1. Enzymatic Desizing 2. Oxidative Desizing 3. Mechanical Desizing

  21. Enzymatic Desizing Enzymatic Desizing: Here amylase enzyme is used widely and this is the most popular method of removing starch. Amylase breaks down the long water insoluble starch molecular chain into water-soluble smaller sections (sugar), which can be washed away very easily. During removal of starch it also removes some indigo from the fabric, which is also a great advantage for Denim wash as this produces frosty effect. In case of size binder components, PVA, sizing waxes lubricants, which are not cleaved by enzyme or impossible to remove by enzymes, are removed by hot wash with detergent. But this detergent should be compatible with enzyme.

  22. Enzymatic Desizing Recipe & Purpose Of Chemicals: Chemicals Name Dose % WOG Purpose Amylase Enzyme 1-3%; As recommended Breaks molecular chin into smaller section & this is soluble in water down the longer starch Surfactant As recommended 0.2- 1.0% Wash off the sizing Compatible with enzyme & others. Fixing agent As recommended 0.5- 2.0% Fixing the dyes & reduce Wash-off of dyes. Temperature & Time As recommended 140 F- 150 F & 40-60 min Smaller section of starch, Wax binder converted to components Water soluble L: R 1:5-1:10 PH 6-8 It helps to prevent back staining. After drain a hot wash 50C for 5-3 min required for cleaning the desize chemicals. Here it is very important to introduce hot water because introduction of cold water re-solidify the fat and wax.

  23. Enzymatic Desizing Reaction Of Alpha Amylase With Starch: CH2OH CH2OH CH3 O O O OH OH OH O OH OH OH CH2OH CH2OH O O O OH OH OH OH O OH OH OH Alpha-amylase enzyme attacks the starch only at the alpha 1-4 linkage, producing water-soluble dextrine i.e. soluble sugars. The progress like as: Starch → dextrine → maltose → glucose (water-soluble)

  24. Oxidative Desizing Oxidative Desizing: This method is considered as faster than biological process & this can also cleaves PVA sizes, which are not broken by amylase enzyme. As many denim fabric manufacturers apply size with a combination of starch and PVA this process gives us an advantages over biological or enzymatic desizing in case of removal of PVA. CH2OH CH2OH CH3 O O O OH OH OH O OH OH OH CH2OH CH3 O O OH OH OH OH

  25. Oxidative Desizing Recipe & Purpose Of Chemicals Chemicals Name Dose % WOG Purpose Non-ionic/Anionic Surfactant As recommended 0.5-1.0% Wash off of the size ingredients Hydrogen per oxide 35% 2-4% It cleaves the starch & make it water soluble. Alkali (Soda,NaOH) 0.5-1.0% Maintain PH 9-11, Increase of sulpher dyed garments PH should be below 10.5. Stabilizer 0.6-1.5% To stable H2O2 Fixing agent As recommended 0.5-2.0% Fixing the dyes & reduce Wash-off of dyes. Temperature & Time As recommended 140 F-150 F & 10-30 min Broken starch, wax, Binders converted to water soluble with the help of temp & time. L: R 1:5-1:10 After drainage a hot wash or hot rinse required for removing the desize chemicals. A neutralizing (with acid) process is required which depends on the type and requirement of next process.

  26. DENIM BLEACH Denim bleach In this process a strong oxidative bleaching agent such as sodium hypochlorite or KMnO4 is added during the washing with or without stone addition. Discoloration produced is usually more apparent depending on strength of the bleach liquor quantity, temperature and treatment time. It is preferable to have strong bleach with short treatment time. Care should be taken for the bleached goods so that they should be adequately antichlored or after washed with peroxide to minimize yellowing. Materials should be carefully sorted before processing for color uniformity.

  27. DENIM BLEACH WHAT IS BLEACH: A bleach is a chemical that removes colors or whitens, often via oxidation. Common chemical bleaches include household chlorine bleach, a solution of approximately 3– 6% sodium hypochlorite (NaClO), and oxygen bleach, which contains hydrogen peroxide or a peroxide-releasing compound such as sodium perborate, sodium percarbonate, sodium persulfate, tetrasodium pyrophosphate, or urea peroxide together with catalysts and activators, e.g. tetraacetylethylenediamine and/or sodium nonanoyloxybenzenesulfonate. To bleach something is to apply bleach, sometimes as a preliminary step in the process of dyeing. Bleaching powder is calcium hypochlorite. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing. Most bleaches are hazardous if ingested or inhaled, and should be used with care.

  28. DENIM BLEACH BLEACHING WASHING This way be considered as a preparatory process of mercerizing ,dyeing, or printing .therefore proper bleaching should be carried out other wish the subsequent process would be fault. Objective: 1. To remove the size material from the garments. 2. To remove the starch present on the garments. 3. For soft feeling to wear the garments. 4. To increase the color fastness and rubbing fastness. 5. Especially develop the “Bio-polishing’’ affect cotton/Denim. 6. Enzyme improves the anti-pilling properties. 7. Enzyme attacks more the surface of the fabrics and gives a very smooth surface.

  29. DENIM BLEACH Different type of bleaching: 1) OXIDIZING AGENT: 1. OZONE (O3) 2. HYDOGEN PEROXIDE (H2O2) 3. SODIUM HYPOCHLORIDE (NaOCl) 4. SODIUM CHLORITE (NaClO2) 5. POTASSIUM DICHROMATE (K2Cr2O7) 2) REDUCING AGENT 1. ZINC DUST (ZnO) 2. SODIUM HYPO-SULPHITE (Na2S2O2) 3. HYDROGEN SULPHIDE (H2S)

  30. Mechanism of bleach action: MECHANISM OF BLEACH ACTION: Color in most dyes and pigments is produced by molecules, such as beta carotene, which contain chromophores. Chemical bleaches work in one of two ways •An oxidizing bleach works by breaking the chemical bonds that make up the chromophore. This changes the molecule into a different substance that either does not contain a chromophore, or contains a chromophore that does not absorb visible light. A reducing bleach works by converting double bonds in the chromophore into single bonds. This eliminates the ability of the chromophore to absorb visible light.

  31. PROCESS CYCLE:

  32. ENZYME WASH WHAT IS ENZYME: Enzymes are proteins Bio catalyze.Its has huge life cell .The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life.Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, called the products. Almost all processes in a biological cell need enzymes to occur at significant rates. Since enzymes are selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell.

  33. ENZYME WASH OBJECTIVE: 1. To remove the size material from the garments. 2. To remove the starch present on the garments. 3. For soft feeling to wear the garments. 4. To increase the color fastness and rubbing fastness. 5. Especially develop the “Bio-polishing’’ affect cotton/Denim. 6. Enzyme improves the anti-pilling properties. 7. Enzyme attacks more the surface of the fabrics and gives a very smooth surface. Types of Enzyme: Mainly two types of Enzyme: 1. Acid Enzyme (a. Powder b. Liquid form.) 2. Neutral Enzyme (a. Powder b. Liquid form.) After enzyme washing we get thise change:  Color  Gsm decrease  Softener  Strength

  34. ENZYME WASH ENZYME WASH It is environmentally friendly wash. It involves the Application of organic enzymes that eat away at the fabric, i.e. the cellulose. When the desired color is achieved, the enzymes can be stopped by changing the alkalinity of the bath or its temperature. Post treatment includes final rinsing and softening cycle. The effects produced by the cellulose enzyme are –  Use of cellulose making the seams, hems, and pockets more noticeable  Salt pepper effect is color contrast effect.  Faded garment with acid cellulose enzyme provides less color contrast in proportion to garment washed with neutral cellulose enzymes. Garment load size of the machine is 35-40 jeans per machine and it cannot be overloaded.

  35. ACID WASH ACID WASH It is done by tumbling the garments with pumice stones presoaked in a solution of sodium hypochlorite or potassium permanganate for localized bleaching resulting in a non uniform sharp blue/white contrast. In this wash the color contrast of the denim fabric can be enhanced by optical brightening. The advantage of this process is that it saves water as addition of water is not required.

  36. PROCESS CYCLE

  37. Mechanical washes

  38. STONE WASH: Stone wash: In the process of stone washing, freshly dyed jeans are loaded into large washing machines and tumbled with pumice stones to achieve a soft hand and desirable look. Variations in composition, hardness, size shape and porosity make these stones multifunctional. The process is quite expensive and requires high capital investment. Pumice stones give the additional effect of a faded or worn look as it abrades the surface of the jeans like sandpaper, removing some dye particles from the surfaces of the yarn.

  39. STONE WASH: LIMITATIONS OF STONE WASHING:  Quality of the abrasion process is difficult to control Outcome of a load of jeans is never uniform, little percentage always getting ruined by too much abrasion.  The process is non-selective.  Metal buttons and rivets on the jeans in the washing machines get abraded.  This reduces quality of the products and life of equipment, and increases production costs.  Stones may turn into powder during the process of making the garment grayish in color and rough too  Provides rougher feel than enzyme wash  Stone may lead the harm to the machine parts MICRO-SANDING There are 3 ways for this technique:  Sandblasting  Machine sanding  Hand sanding or hand brushing

  40. Sand blasting Sand blasting technique is based on blasting an abrasive material in granular, powdered or other form through a nozzle at very high speed and pressure onto specific areas of the garment surface to be treated to give the desired distressed/ abraded/used look.  It is purely mechanical process, not using any chemicals.  It is a water free process therefore no drying required.  Variety of distressed or abraded looks possible.  Any number of designs could be created by special techniques.

  41. Sand blasting

  42. Other washing: -

  43. Rinse wash 1. Chemically bleaching jeans so that the color fades away 2. Breaks down the fibers of jeans and creates white streaks or spots on denim 3. Gives a unique rugged look, also called snow wash 4. Earlier involved the use of pumice stone 5. Presently process involves spraying chemical and removing it immediately 6. Come in colors like blue, black, green, brown, grey etc. Cellulose wash 1. This is done to achieve a wash down appearance without the use of stones or with reduced quantities of stones. 2. Cellulose enzymes are selective only to the cellulose and will not degrade starch. 3. Under certain conditions, their ability to react with cellulose (cotton) will result in surface fiber removal (weight loss). 4. This will give the garments a washed appearance and soft hand. Ozone fading 1. By using this technique, the garment can be bleached. 2. Bleaching of denim garment is done in washing machine with ozone dissolved in water. 3. Denim garments can also be bleached or faded by using ozone gas in closed chamber. 4. In the presence of UV light, there is an interaction between the hydrocarbons, oxides of nitrogen and oxygen that causes release of ozone. 5. Indigo dyestuff tends to fade or turn yellow due to ozone reaction.

  44. Flat finish It is a special process done to impart fabric with an even wash down effect and very clean surface. Originally liquid ammonia was used, but now use mercerization plus calendering processes to achieve the flat surface. Mercerization swells up the cotton fibers and allows the calendering to press flat the surface. They consider this as an imitation process to the use of ammonia, which is toxic and not allowed in commercial use in most countries Over dye 1. Dyeing over the fabric or jeans to add another tone of color 2. Most often used is a 'yellowy' overdye to create a 'dirty' look 3. Also can be applied with spray gun or paintbrush for local coloring Sun-washing 1. A very light shade by bleaching and stoning 2. Looks as if the sun faded the fabric Super dark stone 1. Commercial term for an extra dark indigo color 2. Results from a double-dyeing technique

  45. Snow wash denim Denim treated with a variation of acid wash that imparts bright white highlights. Quick wash denim 1. Aims at minimizing wash cycle time 2. Results in more economical washes and solving many other washing problems faced by launderes during fashion wash cycles 1. The yarns are ring dyed using indigo giving 25 to 30% less fixed dye to obtain a given shade 2. During wash cycle,indigo dye can be removed quickly,giving washed look

  46. Other mechanical washing 1. Whiskering 2. Shot gun denim 3. Water jet fading 4. Super stone wash 5. Ice wash 6. Thermo denim 7. Laser technology finish

  47. Water jet fading 1. Hydrojet treatment is used for enhancing the surface finish, texture, durability of denim garment. 2. Hydroject treatment involves exposing one or both surfaces of the garment through hydrojet nozzles. 3. The degree of color washout, clarity of patterns, and softness of the resulting fabric are related to the type of dye in the fabric and the amount and manner of fluid impact energy applied to the fabric. 4. As this process is not involved with any chemical, it is pollution free. Laser technology 1. It is a computer controlled process for denim fading. 2. This technique enables patterns to be created such as lines and/or dots, images, text or even pictures. 3. It is water free fading of denim. 4. Being an automatic system, chances of human error are slim. 5. Also called spray painting in denims. 6. •This technique has relatively high cost.

  48. Super stone wash It is type of wash treatment of denim garments in which the denim garments is subjected to prolonged stonewash treatment for more than six hours. Soda ash and soap are used for hard wash. Steam is used up to 60-800C for one hour to finish the washing process. It is followed by acetic acid wash treatment and then the garments are neutralized and rinsed. Ice wash 1. Ice washing in denim fabrics is done to remove more than half the dye during washing Thermo-denim 1. Also called double denim. A lightweight fabric (either plain, fancy or colored) is glued to the denim. The glue comes off after washing and the trousers look like they've been lined Vintage 1. Applies heavy stonewashing or a cellulose enzyme wash, with or without bleach 2. Gives an old and worn look

  49. DRY WASHING SECTION Dry wash: Dry wash is mainly done by mechanically or by hand. Different process of dry wash is described below-

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