By: Tanveer Malik and Shivendra Parmar
Department of Textile Technology
Shri Vaishnav Institute of Technology and Science
Baroli (Indore - Sanwer Road), Dist: Indore (M.P) Pin-453331
E-mail: tmalik35@yahoo.com, shivendra_parmar@rediffmail.com
INTRODUCTION:
Unless any product is characterized by value addition it is now impossible to survive in this highly competitive world market. Processing is important to make a usable but finishing gives value addition to it. It makes garments attractive, comfortable & finishing can incorporate desirable properties. Finishing is the heart of textile processing.
Value addition = {(Technology) + (Innovation)} x Quality
Past are the days of traditional and conventional fabrics, which are super fed by fabrics with multi-functional finishes. Indeed, days are now of research and development of a huge spectrum of various advancements in fabric finishes in order to project world class fabric in the world class market at the most competitive rates .a range of new fabric finishes need to developed and manufactured which will give an innovative edge to the textile sector in various applications. In addition to the specialty we are unique for certain special application and more emphasis should be laid on the derivation of various textile finishes with numerous features and characteristics which should be merge for multifold applications to create �all in one universal application�.
Set against following background the driving forces for change in finishing of fabric have been considered to be the need for competitive strategy that utilizes;
� Chemical compatibility to provide one-shot multifunctional finishes.
� Cost reduction through process integration and minimizing the consumption of all utilities.
� More environmentally friendly and application method.
� Cost reduction through minimization of effluent treatment cost.
� Improve process control, monitoring and automation.
� Greater innovation in chemical finishes.
� Quick response through right-first-time, right-on �time, right-every-time finishing.
In this way, it should be possible for finishing department to satisfy the aesthetic and functional performance demands of customers, stimulate the market through the innovation to create greater novelty and variety and maintain a technical and a cost-competitive edge, while providing satisfactory solution to the environmental issues.
Finishing of textile fabric is carried out to increase attractiveness and/or serviceability of the fabric. Different finishing treatments are available to get various effects, which add value to the basic textile material. The domestic readymade garment sector is booming, and garment processing has emerged as one of the important production routes towards meeting quick changing demands of the fashion market. In this article discussed various special finishes to garment.
METHOD OF APPLICATION:
There are two methods of garment finishing.
� Dip process.
� Tumbling process.
6. OZONE FADING IN DENIM FINISHING:-
With finishes a hot concept, garment manufacturers and finishing units are innovating and experimenting with new techniques to get catchy finishes. Ozone fading in denims provides an interesting look to the garment. However, the procedure and methods to be adopted need to be carefully understood.
One of the key noxious by-products of urban photochemistry is ozone and this can reach dangerously high levels of 0.5 ppm. In the presence of UV light, there is an interaction between the hydrocarbons , oxides of nitrogen and oxygen that causes release of ozone (in addition to other compounds). The release is during the day time due to presence of sunlight.
Indigo dyestuff tends to fade or turn yellow due to ozone reaction. Ozone is present in atmosphere in most industrially active and urban dwellings and is formed in the presence of sunlight or UV light. The levels of ozone can reach dangerous levels of O.5 ppm and the deteriorating effect it has on denim apparel (particularly that stored in retail shelves) is practically irreversible.
The fading rate of indigo dyestuff is dependent on
(a) The position of the dye in the fibre
(b) Solubility and diffusion of ozone within the fibre and
(c) Absorption of ozone on the surface of the fibre.
7. MICRO ENCAPSULATION FINISHES:
Microcapsule: In simple terms, ��a miniature container that protects its contents from evaporation, oxidation and contamination until its release is triggered by gentle rubbing or shaking�� during encapsulation, tiny droplets of benefit-laden products such as moisturizers, fragrances, deodorizers, vitamins, or repellants are wrapped with a protective coating to form a capsule.
The micro encapsulation of liquid, non-water soluble substances is one of our areas of high-tech specialism. This involves ��packaging�� the substances in microscopically small capsules to seal them in hermetically, thereby preserving them.
Depending on the application, we can provide capsule diameters from 1 ��. The contents can be released in a controlled way by mechanical action, such as rubbing, pressing, cutting or scratching.
� Place stones and garments in machine (garments should be scoured and/or desized and dry or slightly damp).
� Tumble for 10-30 minutes or until desired effects are achieved. Results are dependent upon dyestuff, fabric, and concentration of chemicals, stones, additives, and equipment.
� In some cases, the stones can be reused for another load before re-soaking, depending upon their porosity. It is advantageous to transfer the garments to another machine for washing, minimizing the number of machines used for the corrosive process of ice washing.
� If potassium permanganate is used, manganese dioxide will form (a brown/orange color) and must be removed by treatment with sodium bisulfite, hydroxylamine sulfate, or acidified hydrogen peroxide as the reducing agent. Fill the machine with water and add 1-5gpl of the reducing agent. Heat to 50c and run for 20 minutes. The process is normally repeated twice to ensure complete removal of the manganese dioxide. When sodium hypochlorite is used the residual chlorine should be removed with sodium bisulfite or hydrogen peroxide. Adding jeans to machine already charged with after wash chemicals will increase contrast.
� Rinse well.
� Repeat step 6 if necessary.
� Apply softener.
� Tumble dry.
� Press, if required.
4.4 Cellulase wash: -
Cellulase enzymes have gained acceptance in the garment wash industry as a means to achieve a wash down appearance without the use of stones or with reduced quantities of stones. These enzymes are different from alpha amylase enzymes used for starch removal in that they are selective only to the cellulose and will not degrade starch. Under certain conditions, their ability to react with cellulose (cotton) will result in surface fiber removal (weight loss). This will give the garments a washed appearance and soft hand.
Procedure: -
� Load stones in machine (normally 0.5-2 part weight stones: 1 part weight garments) if applicable.
� Load garments.
� Desize with alpha amylase enzyme and detergent.
� Rinse
� Add cellulase enzyme (amount, pH, temp. and cycle time dependent upon type of fabric and desired effects; manufacturer�s recommendations should be followed.)
� Adjust pH as recommended.
� Tumble 30-90 minutes.
� Drain
� Rinse well ( 70oC)
� Drain
� Rinse well ( 70oC)
� Drain. Separate garments from stones if used (garments can be transferred to another machine.)
� Apply softener.
� Extract and unload.
� De-stone and tumble dry.
� Press, if required.
After step 7, chlorine bleach may be used as described in stone wash with chlorine.
These are the two machines, which are used for garment steaming and stretching.
8. FRAGRANCE FINISHES:
These are microencapsulated formulations of various fragrances like musk, pineapple, rose, lavender, jasmine, lemon, peppermint etc. which are applied on the fabric with the help of a binder. They impart fragrance when applied in this fashion.
Much of work is concerned with the microencapsulation of fragrance oils, e.g. perfumes and aromatics. The FOLCOScent� brand offers a wide range of technically mature products for scent marketing activities.
Bayer chemicals, a division of Germany-based Bayer AG, recently introduced Bayscent� microencapsulated aromatherapy products to the marketplace. The product features fragrances of Bayscent Neutralizer enclosed in a patented polyurethane microcapsule largely impermeable to diffusion. Fragrances range from fruity to flowery, while the neutralizer is designed to eliminate unpleasant odors.
Textile problem areas subjected to a high degree of stress in treaking mountaineering biling gear or sportswear, such as shoulders, knees and elbows, can be equipped with special more wear resistant fluorocarbon types.
Very soft fluorine polymers are available for woven microfibre fabrics which are very sensitive to harshness of handle due to finishing.
The polymer is modified with specially soft monomer components which have a so called �hinge action� in such a way that the film which these FC polymers form on the fiber is very soft.
9. HIGH �WASH PERMANENT� FC POLYMERS:
Highly cross-linked FC polymers are suitable for distinctive effects and permanence to washing, particularly on synthetic materials. These FC polymer modifications which have long been used in the medical protection textiles field are now also used in the equipment field, as for example in motor cycling clothing.
The high degree of permanence is produced by incorporating additional reactive groups in the polymer, and the co-responsibility often interrelated effect amplifier.
LAD FC polymer:
LAD is the English term for �Laundry Air Dry�.
The effect in the case of a fabric finished with an LAD product is generated simply by air drying. In addition to more optimum film formation, the combination of fluoroacrylate and effect amplifier brings about fluorine side chain stabilization by target produced stabilizing forces during the washing process.
The stabilization reduces fluorine side chain disorientation. While the oil water and dirt repellant properties are retained over the long term even without intermediate heat treatment.
In addition to the above mentioned effect promoting properties, the effect amplifier has high degrees of permanence-promoting reactivity, which already has a complete effect at very low curing temperature.
The technological performance of functional outdoor and active sports wear is considerably improved by fluorocarbon finishing.
10. RESIN LESS SHRINK PROOF FINISH-CELTOPIA
A new shrink-proof process for cellulose clothing material such as cotton or rayon fabrics has been developed. The distinguishing feature of the new process is the achievement of remarkable properties through a physiochemical approach without using any chemical agent such as resin.
There is a crystal conversion from Cellulose I to Cellulose III by liquid ammonia treatment and reconversion to Cellulose I on hot water treatment. The degree of this crystal conversion and reconversion is proportional to its treatment temperature and time.
In other words, cellulose fiber can swell sufficiently through ammonia liquor treatment and at the same time there is crystal conversion from I to III. When hot water treatment is carried out, the crystal reconverts from III to I, but this time without changing the shape of the fiber. These changes occur in the crystalline and non-crystalline region both and hence the whole structure gets stabilized and no deformation due to water absorption will occur afterwards.
Thus, good crease recovery and wash-n-wear properties are achieved. It is easy to pleat during ironing so even tailor-made shirts can be finished.
Further if pleats and creases are added before hot water treatment, permanent durable press finish is obtained. In addition to all these effects, quick property is also achieved in Celtopia finished fabric.
Celtopia as a multi-functional finish:
The features of Celtopia can be summarized as follows:
1. Resin-like shrink-proofing without resin.
2. Durable crease without resin.
3. Possible to wash Rayon and Cupro with water.
4. Less occurrence of skin irritation due to pure cellulose.
5. A fresh feel thanks to the high-level of water and moisture absorbency.
6. Additional quick-dryness.
7. Environmentally friendly.
11. EXTRAORDINARY FINISHES:
11.1 Fabric with pulling power:
A new finish has been developed that involves the fabric to be impregnated with pheromones, which are said to attract the members of opposite sex. These are so-called first-shirt and give its wearers and advantage over their rivals. Pheromones are hormone based scents that arouse the senses of person in vicinity.
11.2 AQUA FINISH:
Uniquely finishes woven fabrics have been produced with hydro entanglement finishing. The principle involved is that the amount of bonding in the fabric is directly related to the energy imparted to the cloth.
The basic process requires the application of high pressure water jets in the form of a curtain on the woven or knitted fabric. The hydraulic energy causes in the cloth to bulk and expand and individual fibers to entangle. The resultant fabric is softer, supple with better drape and durability.
A double sided surface is produced, on the water entry side, the projecting fiber ends are finished into fabric i.e. this side becomes smoother while on the water exit side, small fiber ends protrude, producing a thin pile and thus a fleece like effect is obtained.
The uniqueness of finish is that it is entirely �chemical free� so that there are no effluents in the water stream. The water used for finishing is the standard potable water with special treatment.
11.3 FLOCK FINISH:
Flock is short pieces of monofilament i.e. short fiber material made of viscose, polyamide, polyacrylonitrile, acetate or natural fibers. Even metal flock exists like Aluminum, brass or bronze. Flock adhesive is of three types:
� Thermoplastics (PVA, PVC) and copolymerisates (Acrylic acid)
� Duroplastics (Phenolic resins)
� Elastomers (polyurethane)
Following are the steps of flock finishing:
� Application of adhesive
� Flock application by either of three ways: mechanical, pneumatic or electrostatic.
� Drying at 70 fro 3-5 min.
� Final treatment: removal of excess flock by mech. Suction unit.
The finish is used for inexpensive production of high quality suede, velvet, velour or imitation for effects.
11.4 Leather finishing
Polyurethane softeners provide an elastic handle and produce characteristic rubbery handle which are durable. Softeners based on special reactive polyurethane are marketed by blocking the reactive iso-cyanate groups to ensure adequate storage stability. They are used in conc. Of 2.5% o.w.f. enzyme wash is given prior to the application of polyurethane softener which are generally applied on the fabrics dyed other than indigo.
12. PLASMA FINISHING:
The concept of green production has led to advance alternative environmental friendly finishing technique such as plasma treatment. Chemically reactive plasma discharges have been used in various industrial sectors to modify the surface properties of material for many years, and recently this technique has been further exploited to the textile field. Plasma treatment I\s based on ionized gases produced by electrical discharges. This treatment is highly surface specific and does not affect bulk properties.
The Cold oxygen plasma treatment.
Substrate is treated in plasma chamber at power 100-300 watt about 10-15 Min. the pressure inside the chamber is maintained around 15 Pa. The plasma treated fabric is washed with 1 gpl of non-ionic detergent at 60 degree Celsius for 80 min. followed by hot and cold rinsing and air-drying.
Possible applications for low temperature plasma treatment in vacuum textile technology are currently envisaged in the following fields:
� Anti felting finish of wool-The gas discharge rounds-off the scales of the wool.
� Improving the wetting properties and dyeability of chemical fibers- In this process, hydrophobic chemical fibers are usually rendered hydrophilic.
� Denim fading- The oxygen cold plasma was applied in the desizing & Colour fading treatment of denim. It was believed that the etching property of cold plasma could achieve both desizing & colour fading on denim in one single treatment. This is due to the etching effect of the plasma treatment will increase the water absorbency of the cellulose fibers on denim &hence their strength.
� Increasing the adhesion of composite textiles like aramid or carbon fibers.
� On treatment of cotton with low temperature low pressure ammonia plasma, it gains chemical reactivity & the cellulose structure changes as if it was a cross-linked one.
CONCLUSION:
The scope of textile finishing is very broad. Only innovative products will be able to open up new markets and new horizons for textile industry. To achieve this it is essential to invest in further research and development.
Globalization has opened the door to competition at the highest level. Every industry should now produce products that are best in terms of quality and price. Customers today have a wide range of choices and the one who produces the best quality at a high competitive price will survive and prosper. The major trust areas in the coming years will very much center around:
1. Customized solution
2. Process optimization
3. All in one universal application.
4. Global competitiveness
5. Technological up gradation
What is needed is not simply conveyance of knowledge but the development of truly creative researchers. The textile industry needs to shift its emphasis from quantity to quality in the new millennium of global competition era.
The driving force for change in chemical finishes are the need for a competitive strategy by cost conscious finisher to add value , enhance quality and provide the greater levels of service to customers through � Right first time, right on time , right every time .� finishing . Compatibility is essential top provide one short multifunctional finishes that can be applied simultaneously
ACKNOWLEDGEMENT:
First of all we would like to express profound gratitude to the management of the institute, Principal Dr.Ing.V.P.Singh,and Advisor Prof. Dr.H.V.S.Murthy and Head of the department Prof.Dr. Prabhakar Bhat for giving encouragement and guidance to write a paper on Special Finishes to Garment � An Overview
REFERENCES: -
1 Contribution Of Specialty Finishes In The Light Of Global Consumer Demand, by Edward Menzes, Rossari Biotech India Pvt.Ltd.
2 AquaTex system for upholstery fabrics, M.hueneke, A.Watzi, Fleissner GmbH &Co., Germany.
3 �LAD Fluorocarbon Technology for High-tech sports wear �By Stefan Thumm ITB 1/2000.
4 �Developing the new dimensions in fabric performance� by Kris Kittelson ITB 5/2000.
5 Encyclopedia of Finishing II
6 �Process optimized silicon softening agent� by Stefan Thumm ITB 4/2001
7 �New Shrink Process for Cellolosic Apparel� by Yuichi Yanai ITB/98
8 NCUTE Pilot Training Programme on �Finishing of garments and knit goods� Sep. 2003
9 www.micro-capsules.com
10 Chemunique, Vol. I, Issue V July-September 2000
11 International textile Bulletin 2004.
About the author:
I am Shivendra Parmar completed my M.Tech in Textile Technology at Textile institute of technology and Science,Bhiwani CDLU University during 2002 .I did my B.E in Textile Technology at Shri Vaishnav Institute of Technology and Science, Indore and passed out in First Class during the year 2002.So far published 4 articles in National and International Journals and presented one paper in national conference. Currently working as lecturer & placement coordinator in the department of Textile Technology, Shri Vaishnav Institute of Technology and Science, Indore. Also contribute in Textile Association Of India,M.P Unit as a Jt. Secertary. Email: shivendra_parmar@rediffmail.com
I am Tanveer Malik completed my M.Tech in Textile Manufacturing at Veermata Jijabai Technological Institute (VJTI), Mumbai University during dec 2001 .I did my B.E in Textile Technology at Shri Vaishnav Institute of Technology and Science, Indore and passed out in First Class during the year 2000.So far published 3 articles in National and International Journals. Currently working as lecturer in the department of Textile Technology, Shri Vaishnav Institute of Technology and Science, Indore.Email: tmalik35@yahoo.com
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Dip process: -
� Dip the garment inside out in finishing chemical keeping MLR 1:5. Washing machine may be used.
� Rotate the garment for 20 min.
� Hydro extract the garment to 70 to 80% pick up.
� Tumble dry at 70 0 C to moisture content 10�12 %.
� Turn the garment right side out.
� Iron/steam press the garment to set the creases at desired places.
� Cure at 150�160 0 C
�
Tumble method: -
In this process the garment are placed (inside out) into a machine with sealed (not perforated) cylinder and application of recipe by either pumping or spraying. The drum is turned for 20 min there should not be excessive dripping of chemicals from the garment. If so more tumbling time is allowed. This method is being used more and more due to the fact that there is no wastage of chemicals. After saturation the garments are hydro extracted tumble dry at 70 0 C to 10�20 % pick up moisture content. The iron and steam press the garments to remove/set creases. Cure at 150�160 0 C for 8�10 min.
Important features: -
� MLR should not be less than 1: 0.85 for the garment weighing 600 gm and 1:1 for those weighing more than 600 gm.
� Minimum time of tumbling should be 20 min.
� Tumble rotation speed 20�30 rpm.
� Tumble drying temp. Should not be more than 70 0 C.
� Moisture retention after drying should be 10�12%.
VARIOUS SPECIAL FINISHES APPLIED TO THE GARMENTS:
1. BIOLOGICAL FINISHES: -
1.1 Bio-polishing: -
To produce this effect cellulose enzymes were introduced. The regular acid acting celluloses produced following effects:
� More cutting
� Color loss
� Prone to contour patches
� Bluish heavy effect
� High back staining
� Economical
However, the desire was for enzyme, which was economical as acid cellulose and properties like the neutral acting celluloses. To achieve this, Genetically Modified enzymes were produced, called GMO's (Genetically Modified Organisms). It is known that enzymes have various activities (Endoglucanase I, II; etc.) Exoglucanase, cello-biohydrolase (CBH II) etc. With the advent of genetic engineering it is now possible to increase or suppress one or more of these activities to achieve tailor made results. The effectiveness of the catalytic core (to hydrolyse glycosidic linkages) depends greatly on the absorption by the CBD tail. When tightly bound to the substrate, certain endoglucanases disturb the crystalline structure and induces the various properties like fading, defibrillation, etc. as a result of the mechano-chemical effect. The G-zyme HCL and G-zyme FF series are products designed for good defibrillation but cuts less colour. The less colour loss is due to the fact that the dye is mostly reacted or embedded in the amorphous regions and the G-zyme HCL acts mostly in the crystalline regions.
Enzymes are naturally occurring proteins that are capable of catalyzing specific chemical reactions. Because they only catalyze the reactions and are not consumed, only a small quantity is needed. Cellulase enzymes are proteins that are capable of hydrolyzing (degrading) cellulose. Two kinds of cellulase are currently available: "acid cellulases" which exhibit the most activity in acid pH range of 4.5 to 5.5 and "neutral cellulases" that are active in the 5.5 to 8.0 pH range. Both enzymes are active within an optimal temperature range of about 45°C to 60°C. After the hydrolysis of cellulosic fibers to the desired extent, changing the temperature or pH level can deactivate the enzyme. Because the enzymes are natural proteins, readily biodegradable, they are a favorable alternative to many finishing chemicals and resins that are currently used.
The bio-polishing process targets the removal of the small fiber ends protruding from the yarn surface and thereby reduces the hairiness or fuzz of the fabrics. The hydrolysis action of the enzyme weakens the protruding fibers to the extent that a small physical abrasion force is sufficient to break and remove them. Bio polishing can be accomplished at any time during wet processing but is most convenient performed after bleaching.
It can be done in both continuous or batch processes. However, continuous processes require some incubation time for enzymatic degradation to take place. Removing the fuzz makes the color brighter, the fabric texture more obvious, and reduces pilling. Unfortunately, the treatment also reduces the fabric strength. Smoother yarns also increase the fabric softness, appearance and feel. Since it is an additional process, the bio-polished garments may cost slightly more. Next time you buy apparel, look for the label "Bio-Polished."
1.2 Denim Bleaching: -
Laccases enzymes are used to get outstanding contrast look on denim fabrics. They also eliminate all the negative effects of the indigo dye redeposition at the same time reducing the time of the process necessary to achieve a highly abraded look. Various effects are obtained on denim fabrics using Laccases.
2 PROTECTIVE FINISHES: -
2.1 Insect Repellent Finishing: -
An ANTIMO MGL a menthoglycol is a natural insect repellent active ingredient, derived from lemon eucalyptus, which is a natural and renewable source. Testing of Antimos MGL with a moderately aggressive cage population of Aedes aegypti mosquitoes resulted in no bites up to at least 4 hours. This indicates that the products has unusual repellency
2.2 Antibacterial Finishing: -
Microbes are minute organisms, which can be most dangerous for creating harm to our lifestyle in different ways. So to make the environment healthy, hygienic and fresh, it becomes very important to have the control over growth of the microbes and for these the garments / fabrics should be treated with some specialty chemicals, which can restrict the growth of these microorganisms. Antimicrobial finishing is one of the special types of finishing given to the textiles where the chances of bacterial growth are high and the safety is paramount.
Biquanides, phenols and their derivatives, isothiazolones, metals, ammonium compounds and alcohols serve as anti-bacterial agents in finishing recipe. Some other important chemicals are Zeolite (inorganic compound of sodium aluminose ), Triclosan ( a phenolic derivative), Chitin (extracted from shells of crabs and shrimps) and Quarternary ammonium compounds.
Action of Antimicrobial finish: -
Anti-microbial treatment on the undergarments controls the growth of microbes on it, which will in turn control the above effects.
Characteristics: -
� This type of finishing inhibits the growth of microbes on the surface of the fabric.
� Maintains hygiene and freshness, stops bad odour.
� Controls or eliminates microbial staining.
� Improves life of the articles wherever it is applied.
� Improves hand of most of the fabric.
� Eliminates the chances of disease transmission.
Effective on any substrate like cellulose, synthetics as well as their blends and any surface other than textiles.
Antibacterial chemicals: -
3 FUNCTIONAL FINISHES: -
3.1 Cool Finish (Snocool): -
When temperature rises, we tend to sweat. This is a natural reaction of our body to maintain the temperature around 97�F.The sweat when evaporates, takes along with it heat equivalent to heat of evaporation of water, thereby maintaining the temperature of the body. The Snocool finish uses the moisture management route i.e. it will enhance the natural phenomenon of sweat evaporation. This finish absorbs and dissipates sweat evenly throughout and thus gives a cool feeling to the wearer.
Characteristics: -
� Garments finished with Snocool produces a cool effect.
� the finish has two fold effect, it reflects light (special polymer) and transfers moisture faster than normal from body to fabric and finally to the atmosphere.
� these finishing agents can be manufactured with or without fragrance.
3.2 Thermocat Finishing: -
� A finishing agent for producing heat retaining effect.
� This type of finishing when applied to the fabric keeps it warm.
� Produces heat retaining effect due to infrared radiation owing to its porosity.
� Especially suitable for 100% cellulose and its blends.
3.3 UV Protective Finish: -
The protection offered by UV cutting fabrics is expressed in terms of UV protection factor (UPF) or sun protection factor (SPF), which are equivalent to the user. UPF of 40 for a garment means the wearer can stay 40 times longer in the sun before skin reddening (erythema) sets in. other words if skin reddens in 15 minutes without UV cutting garment, the same level of reddening would take 10 hours, when UV cutting garment is worn. This means that UPF is a ratio of the time taken for skin reddings with and without protection.
Some facts and figure about UV cutting fabrics:
Cotton and silk display a high degree of UV transmission, hence the wearer needs more UV protection wool displays a low degree of UV transmission., hence the wearer may not need extra UV protection polyester fiber absorb UV rays by virtue of its chemical nature and the de-lust rant which it contains, hence the wearer may not need protection from UV.
Cotton fabric with porosity higher than 5% cannot have UPF of >20, despite the application of a UV absorber. If fabric porosity is too high, the UV absorber will not be effective even if applied in high concentration.
� For textiles needing UPF of 40+, the porosity must be <2%.
� Thicker textile materials have higher UPF
� Textiles treated with OBA show high UPF
� Textile dyed in dark shades display higher UPF
� UPF drops at least by half when fabric is stretched by say 10%
� UV absorbers are applied in higher than required dosages to minimize the risk of loosing UV protection when the garments get wet.
Japanese have though of �endless effect� meaning the �value-addition� to last the life of a textile material is mixed into the fiber core at the melt spinning process. This can absorb UV rays (UV cut effect) and also can reflect visible rays (heat shielding effect).
Characteristics: -
A specialty finishes for protecting the fabric from UV radiation. Protects human's underlying tissues from UV radiation. Protects against short wavelength radiation i.e. from 100 - 400 nm, Non-yellowing. Should be applied during dyeing under a reductive process Applicable by exhaust as well as padding method.
3.4 Flame Retardant Finish: -
Flame retardant finishing is not any finish used for textiles, but it is the need of an hour. The finished material is used not only to produce garments but carpets, curtains, etc. which are used in public places like hotels, theatres etc. The effective flame proofing of the materials used in these areas are of paramount importance.
Characteristics: -
Can withstand at least 50 washings. It also exhibits excellent fastness to dry cleaning using chlorinated solvents. Its application practically does not cause yellowing and modifies the handle of the articles. It is recommended to apply Flame shield CV 20 with thermosetting resins. Any change of the mechanical resistance of the articles treated with Flame shield CV 20 is generally low. However, the simultaneous use of thermosetting resins may result in an important loss of the strength, up to 20% of the initial value. In such cases, the use of polyethylene emulsion allows a significant minimization of the tensile strength loss.
3.5 Peach Skin Effect: -
In classical finishing of lyocell, peach skin effects are produced in rope form using Airflows and Air tumblers. Alternatives are produced in open - width finishing with special emery finishes e.g. emery papers coated with diamond dust are recommended which imitate effects comparable with the classical method.
Apart from Peach Skin effects, various finishes can naturally be applied to fabrics of Lenzing Lyocell such as calendaring, embossed effects, crepe or other special effects. With a liquor ratio of 1:12 to 1:15, the preventive agent against running creases, the dispersing agent, acetic acid and sodium acetate (0.5 gpl) are added initially. It is necessary to choose preventive agents against running crease and dispersing agents that do not hinder the activity of the selected enzyme (cellulose). The liquor is heated to the given optimum temperature (45 - 60�C) .The pH is adjusted with acetic acid (pH 5.5 - 4.5) followed by the addition of enzyme.
Enzymatic treatment: (Machine: Thies Roto Stream)
Fibrolube HML: - 3.0 - 4.0 gpl
Kleerix CR: - 0.5 - 1.0 gpl
Genecel GLA: - 2.0 - 3.0 gpl
pH is adjusted to 5 with acetic acid and sodium acetate. Fabric is treated at 60�C for 60 min. Enzyme activity is inhibited by heating up to 85�C. Warm and cold rinsing is finaly given to the fabric.
3.6 AquaTex Finish: -
Traditional finishing processes for these fabrics usually require the addition of chemicals, in reality; however, these chemi�cal compounds cause a shortening of the life span of such a fabric, its per�formance, and prohibit the possibility of recycling, and frequently involve signifi�cantly higher additional expenses for wastewater treatments.
The AquaTex system or for the enhancement of woven and some knit fabrics has been developed In lieu of these chemicals, which frequent�ly are environmentally undesirable, the AquaTex system only uses regular water at ambient temperature to achieve accept�ability of such fabrics in the trade and ac�tually make them more marketable.
Main advantages of the aqua-tex system: -
� Increased thickness and density - the weave con�struction can usually be reduced significantly - and (he physical properties remain the same or actually improve.
� Softness - the fabric usually does not need any additional processes to obtain this property.
� Improvement In abrasion resistance - up to 50 % higher.
� A permanent mini-velourcan be obtained in fabrics, which have spun weft or warp yarns.
� The fabric surface is very clean.
� Improved definition and clarity of the design and the colors.
� Reduced or eliminated use of environmentally harmful chemicals.
� More cost effective - elimination of traditional finish�ing processes.
3.7 Feather touch & ultra soft touch: -
Feather touch & Ultra soft touch finishes are commercial names produced by treating with Amino, carboxy, or Epoxy Silicones alone or in successive treatments. Amino Silicones Extensively available in market are widely used in softening. They impart excellent softness With Bounciness when used in concentration 2.5 �3% owf in garment finishing. Yellowing and some level of hydrophobicity are the disadvantages. Epoxy silicones, which are most compatible with most of the other finishing chemicals, Impart softness without yellowing and improved fabric strength. They play a vital role in Wrinkle free finishes by imparting improved tear strength.
3.8 Rubbery touch: -
Rubber latex provide glossy, crispy handle with characteristic rubbery effect, which are durable. This effect gaining much more importance among the youngsters. In leather finish they are applied as final finish treatments after enzyme or stone wash or after mechanical abrasion and enzyme treatments. Many catching names such as �Bio polished &rubbery touch finish�, enzyme Bio polish & rubbery touch finish�, are quite common.
Preparation and application of emulsions: -
For finishing of textiles it is necessary to prepare aqueous baths with emulsions or micro- emulsions of silicone softener. The advantage of micro-emulsions is their thermodynamic stability and the drawbacks are higher fraction of surfactants and lowering of softness effect. Using non-ionic surfactants it is possible to prepare stable dilute micro-emulsions with more than 40% strength. The softness produced by micro-emulsions is similar to that of solvent solution. During application on jets it is necessary to control the liquor ratio as well as temperature and shear forces, to prevent the separation and silicone oil and formation of spots. The finishing of synthetics is less sensitive than that of cotton.
3.9 Non-stick Teflon spray: -
This is anew generation multipurpose lubricant based on poly tetra fluoro ethylene (PTFE). In service this lubricant forms a tenacious non-stick coating of the fluoro-polymer, which does not allow dirt and dust to settle on the textile surface. This makes the product ideal for cement plants, textile mills and industries etc. where constant flow of dust and contaminants affect the conventional lubricants.
3.10 Wrinkle free finishes: -
Easy care finish producing cross-linking agent to avoid crease formation. It gives improved dimensional stability to the garments. But crease recovery property should with stand for repeated washes.They must suitable for cotton, P/C,P/V, blended fabric.
3.11 Water repellent finishes: -
Water and stain resistant finishes on fabric has gained considerable popularity amongst youngsters Water resistant finishes can be produced using Metal salts paraffin dispersion, Poly silioxanes, Fluorocarbons, These auxiliaries impart hydrophobic character; and of the above fluoro carbon polymers are extensively used in fabric finishing. They form a film where the fluorocarbon redials are perpendicular to the fiber axis and prevent wetting of the fiber surface. Their high hydrophobic & oleo phobic action is explained by the extremely low interfacial tension of fluorocarbon chain towards all chemical compounds. In actual practice fabrics are bio polished first with enzyme and fluorocarbons are applied either by spray method or dip method and fabrics are finally cured at 1500C for 10 minutes.
Fluorochemicals are organic compounds consisting of per fluorinated carbon chain. This is a film former that reduces the surface energy of a substrate, thereby providing one or more of the following properties:
� Oil Repellency
� Soil Resistance
� Water Repellency
How do fluorocarbons affect the surface tension?
Fluorocarbon from a thin film around the fiber, thus providing the fiber with a lower surface tension, is lower than most liquids. Finishing the fabric with Hydroguard makes the fabric sufficiently water repellent so that it can imitate the lotus leaf. Hydroguard is a special fluoro polymer manufactured by processes that do not produce any by-product.
3.12 Water resistant breathable finish: -
Present trend is to impart water-repellency without affecting water vapor permeability of fabric and garments for use in out door activities; weather-clothing etc. improving the transpiration rate of perspiration through the textile material is particularly important in sports activities where the relative metabolic rate is high. Water droplets but allow the escape of water vapor. Such types of garments are designed for sports-wear, tracksuits, clothing for mountaineering etc.
The chemicals consist of Quaternary ammonium Salt with the pyridine Base and a compound is formed with cellulose in the presence of sodium acetate.
The process sequence employed is pad �Dry �Cure-Soap-Rinse
Pad - water repellent chemical
Drying - 60-70 �C
Curing - 1200C for 2-3 mins.
3.13 Soil release and stain release finish: -
Soil release and stain release and stain release finishes are particularly important where leisure or sports are activities may lead to greeter incidence of soiling and staining. Another factor is the trend towards lower temperature washing of garments where the removal of persistent soil and stain removal becomes more problematic.
On this principle three major groups of finishes are developed.
� Finishes containing carboxylic groups.
� Finishes containing oxy ethylene and/ or hydroxyl groups.
4. WASH DOWN OR BREAK IN LOOKS: -
Wash down effects can be achieved by a variety of garment processing techniques which are mainly dependent on physical and on chemical abrasion of the surface dye there by producing different wash down or break-in looks. Garment dyed with indigo, pigments, reactive, vats, are washed in garment washing machine machines to affect a look to dyed fabrics. In garment washing the seams, waistband, pockets, cuffs, etc develop a contour, which can be obtained by washing in garment from only.
Washing down of garments is the latest development in fashion technology. Washing brings out special effects changing the feel and look of garments. Five good reasons can be attributed for washing the garments.
� To influence physical properties such as softness, handle, drape or fall , absorbency, creasing etc.
� To influence appearance by altering the nature of yarn of fabric or lusture.To create shrinkage & effects of shrinkage like puckering of garments.To create abrasion & related effects.
� To create a trend in fashion with consistent quality & brand image with range of finishes.
4.1 Stone wash: -
Pre-washed, abraded, faded either regular or irregular looks are produced by subjecting the dyed garments to severe washing treatments commonly known as stone wash garments.
In order to accelerate the garment wash effect and to give garments an even more unique appearance and softer hand, abrasive stones were introduced to the wash bath. A variety of natural synthetic stones are available for stonewashing with perhaps the most widely used being Pumice or volcanic rock. As the stones are used, they slowly disintegrate, reducing the severity of the stonewash effect over a period of time. The stones not only abrade the fabric but also gradually corrode the inside of the rotary drum. A machine used for stonewashing should not be used to dye when abrasion would be detrimental to the fabric.
Procedure: -
� Load stones into machine.
� Load garments into machine (ratio usually 0.5 - 3.0 part weight stones part weight garments).
� Desize with alpha amylase enzyme and detergent. Liquor ratio 5-8: 1.
� Rinse.
� Refill and tumble with stones 30 to 90 minutes, depending upon desired effect. Liquor ratio 5-8: 1 at 50-70C. Scouring additives can also be used.
� Drain. Separate garments from stones (garments can be transferred to another machine). Rinse.
� Apply softener (garments can be transferred to another machine for softening).
� Extract and unload.
� De-stone and tumble dry. Press, if required.
Softeners and/or lubricants can be added during steps three and five to reduce creasing potential. Steps 8, 9, and 10 may vary depending upon individual mill arrangement
4.2 Stone wash with chlorine: -
By incorporating chlorine in the stonewash procedure, a col or reduction of the indigo (or other chlorine sensitive dyestuff) is obtained. It is very important that any residual chlorine be removed before drying to prevent fiber degradation. This is accomplished by using an antichlor step with sodium bisulfite or hydrogen peroxide.
Procedure: -
� Load stones into machine.
� Load garments into machine (ratio usually 0.5 - 3.0 part weight stones: 1 part garments). Desize with alpha amylase enzyme and detergent (liquor ratio approximately 10: 1). Rinse.
� Refill and add sodium or calcium hypochlorite.
� Heat to 55 0 C.
� Tumble 15 minutes.
� Add second portion of sodium or calcium hypochlorite.
� Tumble 15 minutes Maintaining temperature of 55 0 C.
� Drain.
� Rinse well.
� Antichlor with sodium bisulfite or hydrogen peroxide.
� Drain.
� Separate garments from stones (garments can be transferred to another machine). Rinse well.
� Apply softener.
� Extract and unload and De-stone and tumble dry.
� Press, if required.
Amount of sodium or calcium hypochlorite required will vary depending upon desired level of bleach down and the sensitivity of the color to chlorine. Each addition can range from 0.075% to 0.225% available chlorine. pH should be kept above 9.0, preferably 10.5-11.0. This is accomplished with the addition of soda ash with each addition of hypochlorite.
4.3 Ice wash: -
Either by accident or experimentation, a method was developed in which stones are used as a vehicle to deposit a chemical on garments to strip the colour. This surface deposit of chemical removes the color only on the outer surface of the garment and produces a frosted appearance. Indigo and selected Sulphur dyes are currently the most candidates for this procedure
Procedure:
� Soak stones in solutions of potassium permanganate for 1-2 hours. Concentrations ranging from 1.5% to 5% are being used commercially. (5% to 10% NaOCl can be substituted.)
� Stones should be drained of excess liquor. This can be accomplished by placing stones in net or mesh fabric prior to soaking. Then the stones can be removed and the excess drained off. Another alternative is to place the stones in a rotary tumble machine along with �waste� fabric and tumbling for several minutes to remove the excess solution. A third alternative is to use any number of the pre-soaked stones or materials available from suppliers. These are available in many different shapes with varying levels of chemical and other additives that produce different effects. Trials should be conducted to determine thee best method for achieving desired effects.
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