denim finishes


Post on 27-Jan-2015




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All types of finishes of Denim garments


  • 1. Stone wash

2. Stone washStone washing of denim fabric gives"Used" or "Vintage" look on thegarments.This is due to the varying degree ofabrasion in the garment.The traditional stone washing of denimgarments normally carried out withpumice stones to achieve a soft hand anddesirable look.The pumice stones having oval and roundshape with a rough surface, work as anabradant in washing cycle.The variations in shape, composition,hardness and porosity gives differentwashing effect in the denim fabric. 3. Stone washProcess Seq.During washing, these stonesscrap off dye particles from thesurface of the yarn of the denimfabric which shows a faded,worn out and brilliance effectin the denim fabric.Due to ring dyeing of denimfabric and heavy abrasionduring stone washing, thefading is more apparent butless uniform.Stone washing makes the denimgarments more supple so that itfits comfortably. 4. Pumice StonesPumice is a natural volcanic stone used for stone washinggarments. It is crystallized with substantive pores.Pumice is mostly used for stone washing due to its durability tochemicals treatment, its strength and light weight. 5. Stone wash ProcessIn order to get the desired washed effect, the stone should be ofproper hardness, shape, and size.For heavy weight denim fabric large and hard stones are suitableand smaller and softer stones are suitable for light weight denim.Stone wt. /fabric wt. = 0.5 to 3 /1The degree of colour fading during stone washing depends onseveral factors, such as, garment to stone ratio, washing time, sizeof stones, material to liquor ratio and load of garments.The washing time may varies from 60 - 120 min. Stones may bereused until they disintegrate completely. 6. Limitations of Stone washStones may cause wear and tear of the fabric and may damage towashing machine due to abrasion of the stone.It may also create the problem of environmental disposition ofwaste of the grit produced by the stones.Increase the labor cost to remove stone dusts from finishedgarments.The denim garments is required to washed several times forcomplete removal of the stones.The process may cause back staining and re-deposition.The process is non-selective.Metal buttons and rivets in the denim garments as well as thedrum of the washing machine get abraded which substantiallyreduces the quality of the garment and the life of the equipment. 7. Synthetic StonesIn order to find an alternate to pumice stone synthetic stones havebeen introduced.These synthetic stones are produced from abrasive material suchas silicate, plastic, rubber or Portland cement.The advantages of synthetic stones in stone washing are:The major problem faced by using the pumice stone has beenovercome.Synthetic stones are more durable than pumice stone and can berepeatedly used from 50-300 cycle.The washing effect may be manageably reproducible.They cause less damage to machines and garments. 8. Perlite An alternative to PumicePerlite stonewash is a new stonewashing process.Perlite is a naturally occurring silicon rock, contains 2-6% ofwater content in it.Due to this reasons, when heated at a particular temperature,perlite expanded 4 to 20 times of its initial volume.These properties of perlite make it suitable for stonewashingprocess.Perlite offers less damage to washing machine than pumicestones.It gives better supple and softer finish to denim garments. 9. Acid wash 10. Acid WashAcid wash on denim jeans is becoming very popular due to itssignificant contrasts and attractive appearance in color.Acid wash can be carried on Indigo & Sulphur base fabricgarments.Acid wash is a chemical wash on denim which stripped the toplayer of color and make a white surface while the color remainedin the lower layers of the material, giving it a faded look.This wash is being carried out by pre soaking stones in bleach andthen followed by neutralization.Acid wash of denim garment normally carried out by tumblingthe garments with pumice stones presoaked in a solution whichcontains sodium hypochlorite (5 to 10%) or potassiumpermanganate (3 to 6%).This cause localized bleaching which produce non uniform sharpblue/white contrast. 11. Acid Wash GarmentsIn this wash addition of water is not required. The colorcontrast can be increased by optical brightening treatment. 12. Acid Wash Process Sequence 13. Acid Wash Limitations & RemediesLimitations of acid wash:Acid washed, indigo dyed denim has a tendency to yellow afterwet processing.The major cause is residual manganese due to incompleteneutralization, washing or rinsing.Remedy:Manganese is effectively removed during laundering withaddition of ethelene-diamine-tetra-acetic acid as chelating agent.Acid washing jeans avoided some of problems of stone wash, butcame with added dangers, expenses, and pollution. 14. Enzyme wash &Bio Polishing 15. Enzyme washIn order to minimize the adverse effectof stone-washing, the denim garmentsis washed with enzymes.The enzyme breaks the surfacecellulose fibers of the denim fabric andremoves during washing.During enzyme washing certainamount of indigo dye and cellulosefibers from the surface of the fabric areremoved. 16. EnzymesEnzymes are proteins, found in all living organisms, plants,as well as animals and microorganism.All organisms produce a wide range of enzymes.Enzyme washing is ecologically friendly due to the naturalorigins of enzymes.Enzymes basically catalyse specific chemical reactions andare known as bio-catalysts.Enzymes act on living cells and can be work at atmosphericpressure and in mild temp and pH. 17. Enzymes Lock & Key 18. Enzymes Lock & KeyThe basic mechanism of enzyme reaction consists of binding of thesubstrate to the active site on the enzyme which causes changes inthe distribution of electrons in the chemical bonds of the substrate.This ultimately causes the reactions which lead to the formation ofproducts.The products are removed from the enzyme surface whichregenerates the enzyme for another reaction cycle.The active site of enzyme has a unique geometric shape which iscomplementary to the geometric shape of a substrate molecule.Due to this reasons enzymes specifically react with only one or avery few similar compounds.Enzymes are highly specific and the specific action of an enzymewith a single substrate can be explained by the "lock-key theory". 19. Enzymes ReactionsEnzyme molecule has formed a complex with the substrate tocatalyse a reaction.The binding sites of the enzyme recognize the correspondingdomain of the substrate.After proper orientation of the molecules, the reactive site of theenzyme molecules have access to the appropriate part of thesubstrate molecule.When the reaction is over, the product formed quickly detachfrom the complex.The model of enzyme substrate elementary reactions is explainedby the Michaelis-Menten mechanism. 20. Enzymes Reactions Michaelis-Menten mechanism.The basis of the Michaelis-Menten mechanism of enzyme action. Only afragment of the large enzyme molecule E is shown 21. Enzymes ReactionsThe enzymes used in bio-stoning are "cellulases."Cellulase acts mainly on the surface of the fiber, but it leaves theinner intact.Cellulase removed by partially hydrolyzing the surface of the indigodyed fiber of denim fabric.Cellulases are blends of selective enzymes that break down celluloseinto glucose.Cellulase enzyme can be classified according to pH range in whichthey are more effective, such as acid, neutral and alkaline stablecellulases.The first two types are commonly used. 22. Enzymes ReactionsAcid Cellulase : pH range of 4.5 - 5.5 , temp. 50 C.Neutral cellulose: pH 6 - 7.0, temp. 55 C.Neutral cellulase is preferred to acid cellulase due to little or noback staining, less loss of strength and weight.Acid cellulase are lower in costs and shorter enzyme cycle time ascompared to neutral cellulase.Cellulases are used under biological conditions of temperature 40 -60 C and pH.Cellulase enzymes are used in stone washing process. So, less stonesare required and causes less damage to the machinery and fabrics.Cellulase treatment on fabric reduce fuzz and pills, increasedsmoothness, softness, luster and brightness, improve fabric handleand drapeability and increase the wash down effects. 23. Advantages of Enzymes Cellulase is economical and environmentally friendly ascompared to stone washing using pumice stones. The percentage of fabric damages has been reduced withcellulase treatment. The enzymatic treatment of denim fabric ensures the sameresult by consuming less water and time, resulting less wasteand damage to machines. The pollution, quality variability, and imperfections alsoreduced in enzymatic treatment. The enzymes can be recycled. 24. Advantages of EnzymesThe productivity of washing is increased due to the spaceformerly taken up by the pumice stones in the washingmachines can now be filled with more jeans.The time consumption for removing stone fragments from thedenim garments has been eliminated in cellulase treatment.The duration or number of rinse washing after enzymestreatment is less than pumice stone-washing.A small quantity of enzyme can replace several kilograms ofpumice stones during washing, which ultimately leads to lessdamage to garment, machine and less pumice dust.Washed garment with soft handle and better appearance isachieved in cellulase treatment. 25. Disadvantages of EnzymesCellulase treatment of denim fabric having somedisadvantages.There may be chances of back-staining in cellulasetreatment.In order to remove the back stating, the garments arerigorously washed.This is added usage of water for the washing. 26. Bio Wash/PolishingThe appearance of natural cellulosic material, such as cotton canbe improved though an enzymatic treatment.This is known as Bio-Polishing. The bio-polishing treatmentremove the fuzz and pilling from the fabric surface and gives thefabric a softer and smoother handle, and superior colourbrightness and glo