denim washing
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY MS Word Export To M ultiple PDF Fi les Softw are - Please purchase license.
Preface All praise is to Allah, Lord of the Worlds, the most Beneficent, the most Merciful and every grace of Allah is on His Prophet Muhammad (P.B.U.H), who is always a source of knowledge and guidance for humanity as a whole. It is a matter of great satisfaction and pleasure for us to present this project. This project report is a part of our Degree program which is done during fourth year of our studies. We chose Denim sector of Textile field as it is a Shinning, growing and challenging field. The entire contents of this report are based on our project in US DENIM. Our major emphasis has been on process, machine and product with the calculations involved. We have included in this project report the technical as well as the Mechanical aspects. We moved department wise covering various aspects. These days of Industrial training enhanced our spirit, courage and confidence. We also improved our presentation and technical skills. Even though every precaution has been taken, it may be possible that any mistake(s) is found. We will feel grateful, if it is intimate.
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
ACKNOWLEDGEMENTS First of all we thank Almighty Allah who brought this moment in our life when we came in US DENIM for the project. It has been a great experience to work with all of you and we are feeling proud that we can say we have worked in US DENIM which is not only one of the best DENIM manufacturer & Exporters in Pakistan but also all over the world and where the management and the workers have demonstrated a very good performance in all areas of the business. US DENIM is a dynamic organization with professionals loving and professionals making setup. As it is said “Time Spent in Training is time Well-spent”. The golden time, which we spend here and the practical, conceptual and industry- related knowledge, which we gained here will be a milestone in our professional carrier. We would like to thanks US DENIM MANAGEMENT Mr. Asif (HR Manager US Denim) Mr. Haroon (Admin) Mr. Bilal Tariq (Production Manager) Mr. Faisal (MT) US APPAREL MANAGEMENT Mr. khurram (HR Manager US Apparel) Mr. Hanif Khan
We are grateful to our class advisor Mr. KASHIF MUNIR for arranging this project. We always remember the hospitality we received during our stay at the US DENIM. We are privileged to work with experienced personnel, who are the master of their skill and field. Their ever supporting behavior, kind advice, and professional approach taught us how to perform tough and critical tasks with utmost ease. We have very much enjoyed being amongst wonderful people. We wish each and every one everlasting progress, success and of course wish US DENIM a very prosperous future.
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Contents _________________________________________________________________________________________
U S Denim Introduction . . . . . .. . . . . . ..….. . .…………..….. .. ... . . . . . . . . . . . .5
T A B L E
History Of Denim. . . . . .. . ………… . . . ………….. .. . . . . . . . . . . . . ………... . .6
Types Of Denim…………………………………………………………….10
Introduction of Cotton………………..……………………... . . . . . ………….…….13 Yarn Manufacturing…………………..…………………..…. . . . . . …………….....14 Warping………………………………..………………..…….. . . . . . ……………....16
Warping in U S Denim……………………………………………………...19
Warping Plan………………………………………………………………...22
Dyeing………………………………….……………..…….…. . . . . . ………….......24
O F C O N T E N T S
Sulphur Dye………………………………………………………………….25
Vat Dye……………………………..…….………………….....……...........30
Denim Dyeing……………………..…….……………………...….……......33
Rope Dyeing……………………..………….…………………...……….....38
Dyeing in U S Denim………………………………………………………..44
Rebeaming…………………………………...………………. . . . . . …….………...46 Sizing……………………………………………….…………. . . . . . ………….…...47 Weaver’s Beam……………………………...………………. . . . . . ……….……...48 Weaving……………….……………………...……….……. . . . . . ….……………..49
Air-Jet Weaving…………………..…………….…. . . . . . …….…..….....51
Weaving in U S Denim…………………..………. . . . . . ……..…..….....54
Finishing…………………………….…….………..………….…. . . . . . ………......56
Singeing…………………………………..…….…...................….…….....58
Mercerizing……………………………..…………...………….….………..62
Stenter…………………………………..……………………………..….....64
Sanforizing…………………………………………………………………...65
Inspection Department……………………..……………………. . . . . . …….…...68 Packing……………………………………..……………….……. . . . . . ……..…...70 Faults……………………………….……………………….…………. .. . . ……....71
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Contents ______________________________________________________________________________________________
U S Apparel Introduction……………….………………………………………….……73 Store Room……………………………….……………………………………….……..75 Cutting Department……………………….……………………………………………..76 Embroidery Department………………….……………………………………………..79 Stitching Department………………….………………………………………………...80
Types of Stitch…………………………………………….…….………………83
Hems………………………………………………………..……………………90
Wet processing……………….….…………………………………………………….93
Chemicals On Denim…………………………………………………….98
Denim Washing. . . . . .. . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . . . . ……110
Mechanical Washes. . . . . .. . ...... . . . . . . . . . . . . . . . . . .. . . . ………….111
Chemical Washes. . . . . .. . . …………. ………. . . . . . . .. . ….... ……...…119
New Development in Denim Washes. ……….... . . . . . . .... . . . . . . …….129
Trimming…………………………..…………………………………………………….132 Buttoning…………………………..…………………………………………………….133 Pressing…………………………..……………………………………………………..136 Finishing…………………………..……………………………………………………..137 Packing……………………..……………………………………………………………138 Glossary Of Denim……………………………………………………………………..139
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US Denim Mills is an upstart denim manufacturing company.
U S
We see ourselves as the foremost source of innovative textile products for today's apparel world and are committed to delivering value to our customers in terms of product development, on-time delivery and high quality. We are responsible to our shareholders for a good return on investment. As corporate citizens we work towards achieving the best environmental and ethical practices. No of Employees more than 500 Established in 2005 Location Lahore, Punjab-Pakistan.
D E N I M
WEAVING
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H I S T R Y O F D E N I M
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HISTROY OF DENIM: In fashion history, jeans and denim history continues to baffle. No one truly knows the perfect answer to where jeans began. As so often happens fashions often emerge together in various parts of the world and are the result of the sudden availability of a new fabric, cloth, dye or technique. But we do know that the phrase denim jeans are thought to derive from several sources. No one is totally certain where the words come from. A majority of source books suggest that denim derives from the English translation of the South of France French phrase 'serge de Nîmes'. Denim fashion history is thus associated with Serge de Nimes. It may well be that the fabric which was made in France also had a version made locally in England and was called by the same name of denim in the same way that Cheddar cheese is called cheddar all over the world. The Serge de Nîmes was originally a wool silk mix, twill weave. Certainly by the 19th century in England denim had a white warp and a navy woof (weft). Denim was considered a hard wearing sturdy fabric, ideal for heavy laboring. When talking about denim the name Levi´ s is one of the first to be mentioned. Levi´ s which stands for Levi Strauss is normally called the forefather of jeans.
When tracing back the history of these trousers to its origins it is true that Levi Strauss played an important role concerning their development and distribution but he had also other inventive business partners. Now the question is: who has sewn the first jeans and where does the history of this „blue phenomenon” begin? Levi Strauss in the year 1860 In 1847, at the age of 17 Levi Strauss left his Frankonian native country in Germany and emigrated to New York together with his family. The members of the Strauss family were capable and skilful businessmen and ran a pedlary at that time. So Levi and his brother followed their parents´ footsteps and also became peddlers. When his great gold rush began in 1850, however, he decided to take part and sent over to San Francisco in California. He took with him a spade, a pick hammer and a bale of fabric out of brown sail cloth which was meant to put up a tent. This did not happen, however: Levi found out that the gold diggers´ hard work in the mines made their clothes get worn out very quickly and he produced stout working trousers out of the sail cloth he had taken with him which 7
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he called „half overalls“. When he continued producing these trousers he used cheap cotton fabrics coming from Genova. At that time Genova was a flourishing place where cotton was exported all over the world. The name of the town of Genova was modified into „jeans” in the American slang. At the end of the sixties of the 19th century he replaced the brown sail cloth by an indigo-dyed, wear resistant cotton fabric coming from France. The name of this fabric was „Serge de Nimes“. Serge is the French Expression for combined twill and Nimes is the French town where the fabric comes from. The fabric´s name Serge de Nimes was quickly turned into „Denim“in American colloquial language. By applying this indigo-dyed combined twill the first jeans out of Denim was almost born or better sewn. The only thing missing were the famous metallic vets. The application of metal rivets for jeans is due to the Polish emigrant Jacob W. Davis, also called Jacob Youphes. Although the working trousers out of Denim were stout they had a tendency to get worn out where the pockets were. Jacob Youphes mended the trousers with a needle and thread. One day a customer inspired him to repair the torn off pockets with the help of rivets. From then on Jacob Youphes made a lot of money out of repairing trousers. Since he was worried that his invention might be stolen he wanted to apply for a patent. For doing so, however, he needed a financially strong partner. For that reason he addressed the manufacturer of the trousers that he mended, Mr. Levi Strauss. Levi Strauss agreed and together they applied for a patent to strengthen the pockets of the trousers and Levi Strauss acquired a share of 50%. This patent was written down in 1873 and can thus be called the true year of birth. Under the management of Levi Strauss the jeans were now produced in series. Since the trousers were so stout not only the gold diggers liked them but which is not surprising in America? The cowboys appreciated them very much, too. When the trousers were applied as working trousers for cowboys, however they got worn out at the crotch tip. This was no problem for Levi Strauss and Co. since they reinforced the trousers again with metal rivets at the crossing point of the four seams at the crotch tip. The metal rivet at the crotch had to be removed quickly since the way of living of the cowboys had not been taken into consideration. The cowboys used to repair their meals at the campfire and then they spent the rest of the evening sitting round the campfire. When the cowboy approached the fire too much at night, however he quickly learned the difference between the physical conductivity of cotton and metal. Those wearing these trousers were then suddenly startled out of their sleep. By knowing very well the need for such a stout garment and thanks to the good cooperation with Jacob Youphes as well as his very good instinct for marketing Levi Strauss is still an important brand name in today’s textile industry. About 1947 denim made a break-away from work clothing image, chiefly in the area of sportswear and rainwear and an occasional appearance in high fashion collections as a "different-looking" evening dress. Jeans fashion history was truly made in the 1950s when film stars wore it in movies that the teenagers of the day followed with avid interest. For many years jeans were only used as work wear clothes, but by the 1940s they were considered leisure wear in America. Once pop and film stars like Elvis Presley, James Dean, and Marlon Brando sported them they became desirable internationally in the 1950s and are associated with rock and roll and pop music. Later in the 1960s, jean brands old and new were worn universally in the 8
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western world. 1970 American youth adopted denim as their favorite fabric. Part of a "back to nature" movement that emphasized ecology and the natural denim being a fabric created from a natural fiber was a primary factor. Since 1960 the jeans business has undergone an explosive transformation, from a source of tough, cheap clothing for cowboys, blue-collar workers and penniless youth into a fashion conscious market for a widening mass of people of almost all ages. Substantial growth in overseas sales of American jeans and denim. Exports of Americanmade blue jeans grew. Overseas manufacturers of jeans also grew. Production of indigo dyed denim started in Europe on an industrial level in 1972. Spreading of jeans fashions in the 1970’s and doubling of denim capacity in U.S.led to the onslaught of imports. From 1976 to 1979 U.S. imports of denim into Europe enjoyed penetration levels between 33% and 42%. European textile industry saw in denim, an opportunity to restructure itself into a more capital intensive high technology industry, thus becoming more competitive against imports from lower-cost countries. From 1972 to 1976 capacities grew from approximately 20 million square meters to 130 million. All mills were basically running at capacity. It was a period of worldwide shortage of denim when demand was substantially greater than capacity. The 1976/7 fashion element subsided in Europe and U.S. Return to specialist jean manufacturer producing basic jeans, with relative little fashion styling. The introduction of "baggy" jeans – originated in Italy where previous shortage led to youth wearing any size jeans available. Since 1978 specialized denim manufacturers re established positions mainly in terms of quality. Indigo denim first produced at Yarraville during 1965 on a narrow width Slasher dyeing machine designed and built on the area. This dyeing method has now been entirely replaced by the commissioning of the Morrison Rope Dyeing Machine on July 4th, 1980. Dyeing capacity 15 to 16,000,000 square meters of denim per annum are possible on this new Morrison dyeing Machine. By the 1980s ripped, frayed and torn jeans were a normal sight. Colored jeans from white through to pastels were also popular as were stonewashed blue jeans. In the 80s, designer jeans with names like Gloria Vanderbilt, Calvin Klein and Armani among so many fashion designers became the designer label jeans to be seen in. Stone washed jeans became a must. By the 1990s black jeans were very popular for a while and jeans in general were seen a lot in the early 1990s. But shades of blue are always loved and sometimes the darkest shade is high fashion and sometimes the most washed out faded pairs become the hottest. Colored jeans of all shades made an appearance. In 2000 designers were crystal beading and silver or gold spraying jeans amid tears, frayed slashes, and fur and feather decoration. Denim was hot yet again and used to make everything from footwear, jackets, bags, basque corsets to jeweled cuffs.
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TYPES OF DENIM While the original denim was a 100% cotton serge material, you can now get it in a variety of materials, including blends that give you the same wonderful look of 100% cotton denim with some great additional features. Denim’s unique look comes from the rich indigo blue in one shade or another woven together with white threads to give the “depth” that people associate with denim. Today, some denims no longer have indigo, but other colors with the white opposing threads, producing denims in a rainbow of shades. DRY DENIM Dry or raw denim, as opposed to washed denim, is a denim fabric that is not washed after being dyed during its production. Most denim is washed after being crafted into an article of clothing in order to make it softer and to eliminate any shrinkage which could cause an item to not fit after the owner washes it. In addition to being washed, non-dry denim is sometimes artificially "distressed" to achieve a worn-in look. Much of the appeal of dry denim lies in the fact that with time the fabric will fade in a manner similar to factory distressed denim. 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 enthusiasts feel to be a more natural, unique look than pre-distressed denim. To facilitate the natural distressing process, some wearers of dry denim will often abstain from washing their jeans for more than six months,[3] though it is not a necessity for fading. Predominantly found in premium denim lines, dry denim represents a small niche in the overall market.
Dry denim can be identified by its lack of a wash, or "fade". It typically starts out as the dark blue color pictured here. SELVAGE DENIM Selvage denim (also called selvedge denim) is a type of denim which forms a clean natural edge that does not unravel. It is commonly presented in the unwashed or raw state. Typically, the selvage edges will be located along the outseam of the pants, making it visible when cuffs are worn. Although selvage denim is not completely synonymous with unwashed denim, the presence of selvage typically implies that the denim used is a higher quality. The word "selvage" comes from the phrase "self-edge" and denotes denim made on old-style shuttle looms. These looms weave fabric with one continuous cross thread (the weft) that is passed back and forth all the way down the length of the bolt. As the weft loops back into the edge of the denim it creates this “self-edge” or Selvage. Selvage is desirable because the edge can’t fray like lower grade denims that have 10
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separate wefts which leave an open edge that must be stitched. Shuttle looming is a more time-consuming weaving process that produces denim of a tighter weave resulting in a heavier weight fabric that lasts. Shuttle looms weave a more narrow piece of fabric, and thus a longer piece of fabric is required to make a pair of jeans (approximately 3 yards). To maximize yield, traditional jean makers use the fabric all the way to the selvage edge. When the cuff is turned up the two selvage edges, where the denim is sewn together, can be seen. The selvage edge is usually stiched with colored thread: green, white, brown, yellow, and red (red is the most common). Fabric mills used these colors to differentiate between fabrics.
Most selvage jeans today are dyed with synthetic indigo, but natural indigo dye is available in smaller niche denim labels. Loop dying machines feed a rope of cotton yarn through vats of indigo dye and then back out. The dye is allowed to oxidize before the next dip. Multiple dips create a deep dark indigo blue. In response to increased demand for jeans in the 1950's, American denim manufacturers replaced the old shuttle style looms with modern projectile looms. The new looms produced fabric faster and wider (60inches or wider), yet lighter and less durable. Synthetic dyeing techniques along with post-dye treatments were introduced to control shrink and twist. Raw selvage is material that has not been washed once undergoing the dying process. It is especially desirable because the material will fade in the creases and folds of the jeans. This process is known as whiskering. Here are some of the newer types of denim on the market: STRETCH DENIM is usually about 98% cotton and 2% Spandex for a bit of that forgiving stretch we all love. This blend gives you wonderful ease of movement and at the same time some support for those “trouble spots” you aren’t so fond of around the hips or thighs. Stretch denim jeans are one of the fastest growing segments of the women’s market for jeans manufacturers.
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POLY DENIM blends appeal to those who like the look of denim but prefer polyester blends that wash and dry quickly and are lighter weight and a bit dressier. These usually appeal to a slightly older market, but are also finding favor for pantsuits, etc. when the look is meant to be “dressy but casual.”
RAMIE COTTON DENIM blends are found in a variety of combinations, with a wide price variance. Ramie is a plant fiber usually added because it reduces wrinkling and adds a silky luster to the fabric. It isn’t as strong as cotton, however, so it has to be blended with this stronger material in order to stand up as a denim material.
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COTTON The botanical name of cotton is Gossypium.
COTTON PROPERTIES Length & Uniformity
Fiber Strength
Upper Half Mean Length
(1/8 in. gauge strength in grams/tex)
Below 0.99
Short
20 and Below
Very Weak
0.99-1.10
Medium
21-25
Weak
1.11-1.26
Long
26-29
Base
Above 1.26
Extra Long
30-32
Strong
32 and above
Very Strong
Uniformity Index Below 77
Very Low
Fiber Elongation (%)
77-79
Low
Below 5.0
Very Low
80-82
Low
5.0-5.8
Low
83-85
High
5.9-6.7
Average
Above 85
Very High
6.8-7.6
High
Above 7.6
Very High
Fiber Fineness
Fiber Maturity
Fineness (millitex)
Description
Maturity Ration
Description
Below 135
Very Fine
Below 0.7
Uncommon
135-175
Fine
0.7-0.8
Immature
175-200
Average
0.8-1.0
Mature
200-230
Coarse
Above 1.0
Very Mature
Above 230
Very Coarse
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YARN MANUFACTURING The initial stage of denim production is Opening and Blending. Opening begins with baled cotton fiber being separated into small tufts. A blend of cotton fibers is made on each opening line. These bales are selected using USDA High Volume Instrument (HVI) data, and PCCA's unique computer blending software produces optimal yarn strength. Cotton is delivered by air suction from the Opening and Blending lines, through additional cleaning and blending machines, to the Cards. The major functions of Carding are to remove foreign matter and short fibers, form the cotton into a web and convert the web into a rope-like form known as a sliver. The drawing process produces a single, uniform sliver from six card slivers. The additional blending, paralleling of fibers and cleaning in this process produces a sliver for Open End and Ring Spinning. For Ring Spinning, however, the sliver must pass through an additional process called Roving. Cotton Fibers are formed into a yarn by centrifugal action in Open- End Spinning. Individual fibers are laid down in the groove of a fast spinning rotor and twisted into yarn. After the cotton fibers are spun into yarn, the yarn is wound into a large package. The Open End Spinning Machines have robots on each side which automatically pieces up (repairs broken ends). On a different track, they have another robot that automatically doffs (removes full packages) and starts up a new package. The size and quality of each yarn end are monitored by the Barco Profile System to ensure uniformity. In Ring Spinning, the spinning frames receive Roving via a transit system from the roving machine. Yarn is formed from cotton fibers that are twisted together after being drafted by passing between three steel rolls and three rubber rolls. The yarn then is wrapped on a bobbin as it spins on a spindle by use of a traveler. The relationship between roll speeds, traveler speeds and spindle speeds controls the amount of twist in the yarn. Ends down levels and production information are gathered by the Uster Ring Expert System. The spinning frames automatically doff bobbins full of yarn and send them to package winding. ACG also has the capacity to produce Amsler Open-End yarn, also known as Faux Ring Spun yarn. This technology enables ACG to impart various slub patterns into an OpenEnd yarn. Denim made from this type of yarn has yarn character and surface interest that cannot be achieved with traditional Open-End yarn.
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BALANCING OF A SPINNING LINE FOR DENIM MANUFACTURING Count 6 7 Production Required per day (kg) 8763 14235 Auto Coro Average Speed 70000 75000 TM 5 4.8 TPI 12.25 12.7 % Installed Efficiency 90 90 % waste 0.2 0.2 Prod/rotor/day 18.515 16.401 prod/day required 8763 14235 rotors 473 868 machines 1.97 3.62 rotors/mc. 240 240 production /month in tonnes 263 427 Count Speed/mt/min Installed n% Production /day Hank Delivered Production Required per day Passages % waste m/c required Cards Doffer dia/ inch Doffer rpm installed effe. % waste hank delivered tension draft production/hr in kg produc daykg production required Machines required Blowroom Lines efficiency Production/day prod required/day lines required
6 700 70 3788 0 8789 1 0.6 2.32 6 27 51 85% 5% 0.1 2 43 1036 8842 8.53
7 700 70 3788 0 14292 1 0.6 3.77 7 27 51 85% 5% 0.1 2 43 1036 14378 13.87
6 90 10800 9308 0.86
7 90 10800 9308 1.4
DrawFrame
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W A R P I N G
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WARPING In general terms, warping is transferring many yarns from a creel of single-end packages forming a parallel sheet of yarns wound onto a beam or a section beam. The warp beam that is installed on weaving machine is called the weaver’s beam. A weaver’s beam can contain several thousand ends and for different reasons it is rarely produced in one operation. There are four types of warping, which are as follows 1. Direct Warping 2. Indirect or Sectional Warping 3. Ball Warping 4. Draw Warping DIRECT WARPING In direct warping, the yarns are withdrawn from the single-end yarn packages on the creel and directly wound on a beam. Direct warping is used in two ways: a) It can be used to directly produce the weaver’s beam in a single operation. This is suitable for strong yarns that do not require sizing and when the number of warps on the warp beam is relatively small. This is also called direct beaming. b) It can also be used to make smaller, intermediate beams called warper’s beams. These smaller beams are combined later at the slashing stage to produce the weaver’s beam. This process is called beaming.
INDIRECT OR SECTIONAL WARPING In Indirect warping, a section beam is produce first. It is also called band warping or drum warping. The section beam is tapered at one end. Warp yarn is wound on the beam in sections, starting with the tapered end of the beam. Each section has multiple ends that are traversed together slowly during winding along the length of the section to form the angle. Due to the geometry of the yarn sections, the last section on the beam will have a tapered end that will make the whole yarn on the beam stable. It is important that each layer on the beam contain the same number of yarns. The same length of yarn is wound on each section.
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After all the sections on the beam are wound completely, then the yarn on the beam is wound on to a regular beam with flanges, before slashing. This process is called rebeaming.
BALL WARPING Ball Warping is mainly used in manufacturing of denim fabrics. The warp yarns are wound on a ball beam in the form of a tow for indigo dyeing. After the dyeing process, the tow is separated and wound on a beam. This stage is also called long chain beaming or re-beaming.
DRAW WARPING Draw Warping is combining the drawing of filament yarns with heat setting and warping processes to achieve uniform stretching and heating for improved dye uniformity, end to end. It is used for weaving of thermoplastic yarns.
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WARPING IN US DENIM: In US Denim ball warping is used. There are three creel machines of GRIFFIN. Two creels have capacity of 420 cones each weather one creel has a capacity of 540 cones. The department is connected with dyeing section directly and working 24 hrs. R &D department inspects the cones which is converted in beams of required length and forwarded to dyeing section.
COMPONENTS OF MACHINE • • • • • •
CREEL LEASING STAND TURN-AROUND ROLL TURN-AROUND STAND BALL WARPER Dual MOTOR DRIVE
CREEL:
Custom designed to meet package dimensions, end count requirements and available space. Electromagnetic Tension Control with individual post adjustment, 0-75 GPE tension range, with individual post-post calibration. Integrated Motion Sensor with 25 19
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millisecond response time, end break indicator, end count confirmation, and recurring break indication for same package. LEASING STAND: Semi-Automatic lease insertion at programmable intervals with ertical oscillation to reduce wear.
TURN-AROUND ROLL: Provides additional length to the yarn path (in sheet form) to allow for recovery of lost or broken ends and reduces rolling in the trumpet at the end of the traverse stroke. TURN-AROUND STAND: Constructed of heavy duty steel with an aluminum flanged 300mm diameter x 125mm wide guide wheel. The guide wheel has a pneumatic disk brake for controlled stops. BALL WARPER: The Ball Warper is capable of producing a 1220mm width ball with diameters up to 1524mm (60”) and safe operating speeds up to 500 mpm. DUAL MOTOR DRIVE: utilizes the latest drive technologies, including AC vector drive/motors, high strength polyurethane timing belts and heavy duty beveled gearboxes. The trumpet carrier; which has no bearings, is machined from thermoplastic to reduce weight and improve durability thus eliminating routine maintenance. Drive Rolls are rubber covered for maximum durability and are coupled to Dual Caliper Disc Brakes for quick stopping. The hold down arms provide programmable hold down pressure and are used in loading and doffing the beam. The Griffin Director is a PC based drive and control system that completely automates the operation of the machine. Operator interface is by 380mm Touchscreen. Customer support is provided through modem communication 24/7 by Griffin technicians. OPTIONAL EQUIPMENT: Automatic Traveling Cleaner, Inside loading/outside running creel design, Manual Post/Disc Tensions, Drop Wire Stopmotion System, Sheet Vacuum System (SVS).
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COMPARISON OF H AND V CREEL H-CREEL Parallel warping is used for sectional warping as well as for direct warping.
V-CREEL V-creel is used for only in direct warping.
Suitable for comparatively low speed warping.
Suitable for high speed yarn warping.
Needs proper yarn guides.
No need of yarn guide
Provide low tension on whole beam.
Provide uniform yarn tension across the whole beam. Free yarn run from creel to the warping machine.
No free yarn from creel to the warping machine because proper yarn guides are required. More time consumable because of low speed. More space is consumed.
Less time consumable.
In indirect warping, a constant speed drive is generally required to provide approximately uniform yarn speed on the surface of the beam. H-creel has a wide range of package change system. Example: with reversible package, with unrolling draw off, with fixed package frames, with package trucks, with swiveling package frames.
Surface friction drive and variable speed drive is commonly used to attain the uniform yarn speed.
Less space is consumed.
V-creel has a low range of package change. Example: reversible frames, reversible frames with automatic knotter, and with traveling package.
PROCEDURE OF WARPING: The creel stand has maximum capacity of five cones per stand. The yarn from the cones is unwounded and passes from rod by cross wound, holed by a catcher guided to the tensioning zone when cone rotates anticlockwise. There are three types of tension in warping i.e. catcher tension, rod tension, and sacker tension. Magnetic tensioner is used for yarn tension. Then the yarn comes to the winding zone or headstock. Combs straighten the yarns towards pressure drum, which supports beam, and yarns in an alignment so that each and every yarn end can wound separately. Static charges due to friction of yarns on metal surface cause static charges, which are removed through an anti static device. Then the yarn is wounded on beam in this way for a required length if beam is changed after one filling of beam then knotting of yarns is made. Similarly if cones are finished on one frame side then trolley system of cone changing is used in this way chains rotates the whole frame of empty side and new filled side of frame is forwarded again knotting is done between the new cones yarn and already winded yarn. Extra yarn is then removed through cutting. Sensors sense any type of yarn breakage and in case of yarn breakage knotting is done. 21
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WARPING PLAN The warper gets the required no of ends and the number of beams from the weaving department and then he made the warping plan that how to complete that task whether on one creel or on more no. of creels. Some examples are given below to show the concept of warping plans using one creel and two creels. For example; If, No. of ends = 1080 No. of beam = 4 Count = 10/s No. of cones in one bag = 16 No. of warper's beams with no. of ends on each = ? Length per beam = ? No. of Bags of 100 lbs = ? Plan for one Creel Then, The total no. of ends on the weavers beam = 1080 x 4 = 4320 ends Cone wt. = bag wt. / no. of cones in bag Cone wt = 100 / 16 = 6.25 lbs Length of yarn on one cone = cone wt. In lbs x count x 768.1 Length of yarn on one cone = 6.25 x 10 x 768.1 = 48006 m lessen the length up to 1 % because of variation in yarn length among different cones length of yarn on one cone = 47600 m no. of ends x no. of beams = total no. of ends 617 x 6 = 3702 618 x 1 = 618 4320 ends so, 7 warper's beams i.e. 6 beams of 617 ends and 1 beam of 618 ends Length / Beam = length of yarn on one cone / no. of beams Length / Beam = 47600 / 7 = 6800 m / beam
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Bags required = No. of ends on warper beam / no. of cones in one bag Bags required = 618 / 16 = 39 bags approx. For example; If, No. of ends = 1140 No. of beams = 4 Count = 10/s No. of cones in one bag = 24 No. of warper's beams with no. of ends on each = ? Length per beam = ? No. of Bags of 100 lbs = ? Plan for two Creel The total no. of ends on the weavers beam = 1140 x 4 = 4560 ends Cone wt. = bag wt. / no. of cones in bag Cone wt = 100 / 24 = 4.16 lbs Length of yarn on one cone = cone wt. In lbs x count x 768.1 Length of yarn on one cone = 4.16x 10 x 768.1 = 31952 m lessen the length up to 1 % because of variation in yarn length among different cones length of yarn on one cone = 51600 m no. of ends x no. of beams = total no. of ends 570 x 8 = 4560 ends so, 8 warper’s beams 0f 570 ends each No. of beams per creel = no. of warper’s beam / no. of creels No. of beams per creel = 8 / 2 = 4 Length / Beam = length of yarn on one cone / no. of beams per creel Length / Beam = 31600 / 4 = 7950 m / beam Bags required = No. of ends on warper beam X no. of creels / no. of cones in one bag Bags required = 570 X 2 / 24 = 48 bags approx.
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R O P E D Y E I N G
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DYEING Dyeing is a process in which we impart colour to the fabric. All commercial textile dyeing processes take place by the application of a solution or a dispersion of the dyes to the textile material followed by some type of fixation process. The dye solution or dispersion is almost always in an aqueous medium. A major objective of the fixation step is normally to ensure that the coloured textile exhibits satisfactory fastness to subsequent treatment in aqueous wash liquors. Dyeing is mainly depends on the type of fabric, structure of fabric and the properties of dyes. Dyes use for Denim • Sulphur Dyes • Vat Dyes SULPHUR DYES: Sulphur dyes are widely used on cotton mainly because they are economical to use. They have good to excellent wash fastness and good light fastness in dark shades. Light fastness of pale shades is poor. Sulphur dyes are usually dull in shade since the molecular structures are complex. As a class, the sulphur dyes are not resistant to chlorine containing bleaches. Chemical nature of sulphur dyes
Partial chemical structures involved in dyeing with sulphur dyes
Dyeing with sulphur dyes of various types
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CHARACTERISTICS OF SULPHUR AND LEUCO SULPHUR DYES ON COTTON: Sulphur dyes have the dullest range of colours of all dye classes but are relatively inexpensive. They are used to dye medium to deep, dull shades on cellulosic materials. There are several excellent blacks giving dyeings with good wet fastness properties. In fact, when black, and deep brown, blue and dull olive green shades are needed, with good washing and satisfactory light fastness at reasonable cost, sulphur dyes are irreplaceable. There are few green sulphur dyes and no true reds. There are, however, an abundance of blacks, blues, yellows and browns. On a world basis, sulphur dyes constitute one of the major dye classes. Sulphur dyes are used in cotton dyeing for woven goods using jig dyeing machines and also in continuous dyeing. They are commonly used for the continuous dyeing of corduroy. They are now being used more widely in jet machines. Sulphur dyes are also used for dyeing denim olive, brown and maroon, rather than the traditional Indigo blue, as well as to ‘bottom’ or ‘top’ Indigo dyed cotton warps. To ‘bottom’ or ‘top’ means that a sulphur dye is applied either before or after the Indigo. The fastness to wet processes and to crocking can be varied almost as required to satisfy the demand for the faded look so popular for denim. This is achieved by allowing premature oxidation of the leuco dye during dyeing, by using short dyeing times so that there is inadequate time for dye penetration into the fibres, and by poor rinsing and soaping after dyeing. The dyeings can then be subsequently treated to produce the faded worn look by removing the surface colour. Although cellulosic goods dyed with sulphur dyes usually have good washing fastness, it can be further improved by resin finishing. The light fastness varies from moderate to good in heavy shades. A major characteristic of sulphur dyes is the poor fastness to chlorine, which distinguishes them from most quinone vat dyes. Dyeings with sulphur dyes cannot be bleached with hypochlorite. In fact, these dyes are readily distinguished from other cotton dyes by their dark, dull colours and the bleaching that occurs when a dyeing is spotted with hypochlorite and allowed to dry. Cotton dyed with some sulphur blacks becomes tendered on storing under warm humid conditions. This is a consequence of the formation of sulphuric acid from oxidation of the sulphur dye in the fibres. It can be minimised by thorough washing after dyeing before the oxidation of the leuco dye, by a final alkaline rinsing with soda ash solution, and by resin finishing. Such tendering is avoided by dichromate oxidation of the leuco dye. DYEING METHOD: Initially the goods are wet out in the bath. Since the dyeing liquor contains appreciable amounts of sulphide, copper fittings must be avoided. If wetting or penetrating agents are used these should be of the anionic type since non-ionic surfactants form stable, nonsubstantive complexes with the leuco thiols. An anionic product such as phosphated 2ethylhexanol is suitable. The bath may then be set at 40 °C with some sodium polysulphide . Polysulphides in the leuco dyebath prevent premature oxidation of the dye and reduce the tendency to bronziness of deep dyeings of blues, navies and blacks. An addition of a sequestrant such as EDTA avoids precipitation of the leuco thiolate by calcium and magnesium ions. The leuco dye is then added slowly and, since the leuco dyes only have low to moderate substantivity for cellulose, some salt may be added initially, or in portions during dyeing, to promote exhaustion. After dyeing the goods are rinsed, the leuco dye oxidised and the dyeing is soaped as for a conventional vat dye.
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Sulphur dyes usually have acceptable substantivity, particularly in the presence of salts, so that stripping in a fresh reducing bath is not easy. Dyeing is often conducted at the boil but this decreases the degree of exhaustion. Sulphur dyes require less salt than reactive dyes and usually have reasonable exhaustion. Low sulphide leuco dyes require more salt and no polysulphide. They do not give good exhaustion in heavy shades and the use of a low liquor ratio is recommended. For popular shades such as black, it has long been common practice to use a standing bath. This is a dye bath that is re-used for subsequent dyeings after addition of more reduced dye. Any free sulphur that tends to accumulate is dissolved by addition of sodium sulphite to give thiosulphate. This prevents it sticking to the goods. The actual dyeing temperature can vary. At higher temperatures around the boil, the bath exhaustion is less but penetration of the leuco dye into the fibres is better than at lower temperatures. POST-DYEING TREATMENTS: After dyeing, good rinsing before oxidation helps reduce bronziness and poor rubbing fastness by removing loosely adhering surface leuco dye solution before oxidation precipitates the insoluble pigment. Once the rinsing is completed, the leuco dye in the fibres is oxidised to the insoluble pigment. Some leuco dyes can be oxidised in air, others need chemical oxidation. Sodium dichromate, hydrogen peroxide, or sodium percarbonate or perborate are used in warm, weakly alkaline solution. The peroxy compounds used for vat dyes can be used for sulphur dyes, but some leuco dyes (redbrowns) are not oxidised by these agents. Some blues are over-oxidised, probably by oxidation of the disulphide links between the heteroaromatic units to form ionic sulphinate and sulphonate groups. This increases the water solubility, decreases the wet fastness and results in staining of other goods during washing. Even sulphur blacks oxidised with peroxides tend to be bluer, lighter and somewhat less fast to washing. The best washing fastness is obtained by oxidation of the leuco dye with sodium dichromate and acetic acid. Sodium bromate (NaBrO3) is now more widely used as an oxidant, particularly in North America. It requires a small amount of metavanadate ion (VO3 –) as catalyst. Some dyeings are treated with copper sulphate, or with this and sodium dichromate, to improve the light fastness, and in some cases the wet fastness. Fabrics for use inside rubber articles should not be copper treated. Some yellowbrown dyes are treated with copper sulphate to improve light fastness but theeffect is lost on washing. The use of chromium salts is now declining because of their adverse environmental impact. Because of their dull colours, dyeings with sulphur dyes are often topped with the much brighter basic dyes. The sulphur dye pigment acts as a mordant for the cationic dyes. Dyeings with sulphur dyes may also be shaded with some sulphide stable direct dyes, but this tends to lower the washing fastness. DYEING WITH SOLUBLE SULPHUR DYES: Large amounts of such dyes are sold in liquid form. They are of two types –1. Watersoluble reduced leuco dyes, and-2. solubilised sulphur dyes – the former being far more important. The water soluble leuco dyes are completely in solution and contain far less insoluble matter than a sulphur dye powder. This is beneficial in package dyeing. They often still require a small addition of sodium sulphide or another reducing agent. These liquids contain the stabilised leuco dye, sodium sulphoxyate-formaldehyde or sulphide and sodium carbonate. The solubilised sulphur dyes are thiosulphate esters prepared from the leuco thiols with sodium sulphite . They usually have low substantivity for 27
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
cellulose and are useful for package, padding and pad–jig applications. Reduction is necessary before or during dyeing and the usual aftertreatments are needed. CONTINUOUS DYEING WITH SULPHUR DYES: Sulphur dyes are used for continuous dyeing of cotton goods using a pad–steam– wash process, with three groups of wash boxes for rinsing, oxidising and soaping. Padding may take place at up to 80 °C to reduce the substantivity of the leuco dye for the cotton fibres. This reduces the problems of selective absorption and the resulting initial colour tailing that it causes. As for other vat dyes, steaming is carried out in air-free saturated steam. Then the dyeing is rinsed at 40–60 °C and oxidised with sodium bromate plus metavanadate catalyst at pH 4 in the presence of acetic acid. In the remaining wash boxes, the best possible soaping and rinsing is done. For black dyes tending to produce sulphuric acid by oxidation on storage, a final soda ash rinse may be added. In some instances better appearances result using a two-pad method. This involves padding with the sulphur dye suspension or solution, followed by intermediate drying, padding with sodium sulphide solution, steaming, and the usual aftertreatment sequence. EXAMPLES OF IMPORTANT COMMERCIAL SULPHUR DYES
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VAT DYES: Vat dyes are mainly applied on cellulosic fibres, but some can be applied to protein fibres. They usually have outstanding colour-fastness properties. Vat dyes are more expensive and difficult to apply than other classes for cellulose such as directs, sulphurs, and reactive. Indigo is a special case in the vat dye class. Indigo is attractive for its pleasing blue colour and for the unique fading characteristics of garment dyed with it. Vat dyes are characterized by the presence of a keto group. Vat dyes in keto form are water insoluble pigments. CHEMICAL CONSTITUTION OF QUINONE VAT DYES
CI Vat Red 42 (1); leuco compound formed by reduction (2); vat acid formed by protonation of the anionic leuco derivative (3); CI Vat Blue 4 (4)
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Reducing vat dyes with hydros
THE SUBSTANTIVITY AND DYEING CHARACTERISTICS OF VAT DYES FOR CELLULOSIC FIBRES BASIC STEPS IN THE DYEING PROCESS: The dyeing of cellulosic materials with quinone vat dyes follows a four-step sequence: (1) Preparation of the vat containing the leuco forms of the dyes; (2) Dyeing of the material, in which the fibres absorb the water-soluble leuco compound; (3) Oxidation of the absorbed leuco compound back to the parent pigment inside the fibres; (4) Soaping of the dyed material to remove pigment loosely adhering to the fibre surfaces and to develop the true shade and fastness properties. DYEING WITH INDIGO AND INDIGOID VAT DYES: Natural Indigo was rapidly displaced from the market once the synthetic product became available. The quality of natural Indigo was quite variable because of the presence of other coloured impurities. The fastness properties of Indigo dyeings are not up to the standards expected from the vat dye class as a whole. It is, however, the appearance of faded Indigo in denim that is so fashionable today. After dyeing, various wet processes, such as stone washing, deliberately enhance this faded effect. Indigo builds up primarily on the cotton fibre surface. This is one reason for the somewhat inferior fastness properties of Indigo compared to quinone vat dyes. APPLICATION OF INDIGO TO COTTON: Dyeing cotton yarn for blue jeans is an important use of Indigo. In a typical batch operation, concentrated reduced Indigo is added to a dyebath from which oxygen has been removed with little alkaline hydros. The goods are entered and fully immersed to avoid oxidation. After about 15 min at 20–25 °C, the goods are removed and well squeezed before air oxidation. Indigo does not exhaust well because of its limited substantivity for cotton, not surprising considering its small molecular size . Deep shades must be built up by repeated dipping in the dyebath after each oxidation. The use of too concentrated a dyebath is not effective for deep shades as it results in poor rubbing fastness. Some salt may be added to aid exhaustion. After dyeing, the goods are well soaped. The final dyed material may be aftertreated to produce a faded, worn look. Continuous methods are used for dyeing ball warps, warp beams and piece goods with Indigo. This is usually carried out in a series of 4–6 wash boxes with upper and lower rollers and nips at the exits. The goods are threaded through each box and may be skyed at the mid-point. The first box is used to wet out the material. In subsequent boxes, the goods are immersed in the leuco Indigo solution for 10–30 s at a linear speed of about 25 m min–1, squeezed and skyed for 2 min to oxidize the leuco dye to Indigo. The boxes are 31
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fed with a stock vat of leuco Indigo and the liquor in the boxes is circulated to maintain constant dyeing conditions. This process of several dips and oxidations is then repeated in a second series of boxes, and so on. Several rinsing and washing boxes complete the process. INDIGOID VAT DYES: Besides Indigo itself, there are a number of other important indigo and thioindigo derivatives used for dyeing cellulosic fibres. These include chlorinated and brominated indigo and thioindigo dyes in which the nitrogen atoms of Indigo are partially or totally replaced by sulphur atoms. Compared to the anthraquinone type vat dyes, Indigoid vat dyes give much paler yellow to brown leuco compound solutions. The vatting process is also slower and requires less alkali.
SOLUBILISED VAT DYES: The solubilised vat dyes provided a means of avoiding the difficult vatting process required for quinone and indigoid vat dyes. The preparation of a solution of a leuco vat dye requires care and time, and protection of the solution from excessive exposure to air. The solubilised vat dyes avoid these problems. These dyes are preprepared sulphate esters of the leuco vat acid. The first product of this type was that derived from Indigo . Later solubilised leuco dyes derived from quinone vat dyes were marketed.
Cotton absorbs these dyes directly from a neutral or slightly alkaline solution but they are not very substantive even in the presence of added salt. Although a leuco sulphate ester has the same negative charge as the normal leuco dye, its charge is localised in the sulphate groups whereas that of the phenolate ion is delocalised. Cotton therefore repels a leuco sulphate ester molecule more strongly than the normal leuco compound. Because of their limited substantivity, solubilised vat dyes are generally only suitable for pale shades. After dyeing, the goods are rinsed or hydroextracted to remove superficial dye solution, and the vat dye pigment is developed in the fibre by oxidation with sodium persulphate or acidified sodium nitrite solution. After neutralising with dilute soda ash solution, the goods are soaped as in the case of normal vat dyeing. The dyeing has the same fastness properties as one prepared from the original vatted pigment. The low substantivity of the leuco sulphate esters avoids the problems of the high strike of leuco vat dyes. Since they can be used in solutions close to neutrality, they can also be used for wool dyeing. Unfortunately, the dyeing and oxidation conditions for each dye vary so it is important to follow the supplier’s instructions. The use of these dyes was never widespread and has declined in recent times. They are not particularly competitive because of their high cost. 32
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DENIM DYEING:The classical jeans was produced out of indigo-dyed Denim fabric. The special character of this fabric – only the warp thread is dyed – makes it necessary to carry out dyeing in yarn form. The yarns applied for Denim were exclusively produced on ring spinning machines in former times. The development of OE(open end) yarns – by applying smaller rotors with a spinning speed of up to 200 m/min – has led to the application of OE rotor yarns both for warp and weft. The yarns applied for weaving must be of high quality: a high fiber for strength, regularity as well as a small part of shortstapled cotton fibers belong to the basic features of the denim yarn. For regular jeans qualities the warp yarns are spun in a fineness of 50 to 90 tex, for the weft yarn the fineness ranges are mainly 75 to 120 tex. If Denim is made out of Tencel or Modal especially for jeans shirts the finenesses are up to 25 tex. Indigo, sulphur and indanthrene are mainly used in the dyeing process. Two methods are applicable for continuous dyeing with indanthrene dyes: rapid dyeing and vat dyeing. While processing the basic colored denim, reactive dyes are used and fixed with hot caustic soda solution. The dyeing process is mainly influenced by the dyestuff characteristics, dyeing temperature and necessary chemicals used in the process. Indigo dye is the most popular choice as it has good depth of shade and suitable rubbing and washing fastness. When cotton yarn is dyed with indigo, it leaves a ring-dyeing effect, because of which the outer layer of warp yarn is coated with indigo, and the core of the yarn remains undyed. This gives the denim garment a unique ‘faded look’ and a rich blue shade after repeated use and wash. Originally, the warp yarns or ends were put through the dye bath side by side to form a sheet of yarn, which passed continuously through several dye baths, squeeze rollers or airing sequences. However, if there were breaks in the yarn (and there would be, as each yarn had to take the tension of being pulled through these processes virtually on its own), the dyeing process had to be stopped. The yarns would be then mended, or else it would lead to very bad tangling. These stoppages would in turn cause large shade variations, and the yarn breaks would show up as bad faults in the fabric. Now, an infinitely more efficient system has been introduced. Special attention shall be paid here to Indigo, the „king of dyestuffs“since it plays an important role in obtaining the jeans effect. Indigo belongs to the category of waterinsoluble dyestuffs. It was first mentioned in a book 13 BC; at that time the name Indian blue indicated the country the color came from. It is said to have been used for dyeing in India and China 2000 years BC already.
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The Indigo plant is used for preparing Indigo
(Indigo tinctoria L.) This plant came to Europe in the 16th century via India and gradually replaced the woad which was one of the most important dyeing plants up to this time. Only the leaves were used for good qualities whereas the leaves together with the stalks were applied for normal qualities. In a vat filled with water and partially with human fermented urine as alkali donor stems and leaves were exposed to a putrefactive process. During this putrefactive process hydrogen was created by means of micro-organisms which, as a reduction agent, transformed the dyestuff contained in the Indigo plant into a watersoluble form. When this process was over the whole mass was filled into a liquid where the fermented mass was stirred with poles. The reason for doing so was to transform the Indigo into its water insoluble form again by air oxidation. In a last step the water-insoluble dyestuff particles could then deposit on the bottom of a stationary vat. Then the liquid standing above was drained and what was left was a thin mash which was dried in the open air and was put on the market in pressed or in powder form
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As shown in figure trading form of Indigo at that time, approx. 9 cm length of edges and 163 g in weight. When looking at these methods one can easily imagine that the reduction of Indigo was considered to be an evil-smelling trade. In 1880 Adolf von Baeyer succeeded in carrying out the first synthetic production of Indigo. In the year 1897 the “Badische Anilin- und Sodafabrik“in Ludwigshafen -hich is nowadays called BASF - was able to carry out an industrial-scale production of the Indigo dyestuff for the first time. A few years later this synthetic dyestuff replaced the indigo coming from British-India almost completely. As was already mentioned Indigo is a dyestuff insoluble in water. In order to be able to apply it on cotton it must be transformed into a water-soluble form. Similar to the former production of Indigo this is done by reducing the dyestuff (ill. 4). In practice this is nowadays carried out with sodium dithionite or hydroxiacetone in the alkaline range.
INDIGO REDUCTION C16H10O2N2 + Na2S2O4 + 4NaOH . C16H10O2N2Na2 + 2Na2SO3 + 2H2O OXIDATION REACTION Na2S2O4 + O2 + 2NaOH . Na2SO4 + Na2SO3 + H2O + C16H10O2N2Na2 + ½ O2 + H2O + Sodium Hydrosulfide C16H10O2N2 + 2NaOH
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Fiber cross-section of a yarn dyed with Indigo This is Fiber cross-section of a yarn dyed with Indigo simplified description of the reduction/oxidation of Indigo In former times dyeing with Indigo was carried out in wood or metal vats, normally in rope form.
Indigo sample dyer as very clearly visible on the above picture, at the bottom side of the rope the water-soluble Leuco form of the indigo is yellowish and on the side of the rope oxidized with air the indigo blue can be seen again. Nowadays, yarn dyeing with indigo is done continuously. Here the various dyeing processes with different concentrations of chemicals as well as the subsequent yarn sizing exert an influence on the quality and the appearance of the ready fabric.
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HOW TO MAKE INDIGO SOLUTION In a tank of 1000 liters: a. take 400 litres of water (soft) b. add setamol ws--> 4 g/l (stirring) ( dispersing solution) c. Add 100 kg of Indigo ( at 1.8 % shade -see the indigo calculations- stirring) d. add caustic soda --> stirring ( for solubilising and pH) e. allow to cool it for 2/3 hours f. Add hydrosulphide ( As reducing agent) g. Make the solution to 1000 l by adding water. If pH is fluctuating, if it is > 11.7 then hydro is added (2-3 kg), if ( 1.8 kg of Indigo 5000 kg of yarn needs --> 90 kg of dye at 100 gpl 100 gms of dye = 1 lit of solution 90 kg of dye = 900 litres 900 litres should be completed in 583.3 min 1 litre would be completed in = 583.3/900= 38.8 seconds so flow rate will be 38.8 seconds / litre Similarly flow rate of caustic and hydro can be determined Hydro is taken around 100 gpl caustic is taken around 90 to 100 gpl
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There are three processes in the practice for continuous dyeing: 1) Rope Dyeing 2) Slasher Or Sheet Dyeing 3) Loop Dyeing
ROPE DYEING: Indigo Rope Dyeing When dyeing according to the rope dyeing or cable dyeing method.350 - 400 warp threads are bound on the ball warper to very thick cables of 10000 - 15 000 m length. On the continuous dyeing installation, 12 to 36 cables are led side by side, wetted, dyed and dried after the dyeing process on cylinders and put into cans. Then the cables are dissolved to warps on the long chain beamer. The warps are added to the sizing machine, sized and then led together to warp depending on the total numbers of threads. In practice, this method has proven to be very good through obtaining an optimum indigo dyeing. However it is important that the cables have a constant tension in order to avoid warp stripes. The disadvantage compared to other methods is that yarn breakages do occur more often. Size of the dyeing unit is between 60 - 80 m. normally, 6 dyeing vats are in use. There are nevertheless variations with 3 to 8 dyeing vats. The dyeing methods described here do not allow a total penetration of the dyestuff during the short dyeing time and give the desired and necessary ring dyeing important for the jeans effect. The sizing process follows the dyeing process of the yarn; this is already visible by the machine sequences and is necessary to stabilize the warp thread against the high mechanical stress while the weft thread is being fed. For sizing the warp, PVA, CMC and acrylate sizes are used besides starch-containing products. ENTERING
FEEDING
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DYEING
AIR TIMING
DRYING
DELIVERY
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PROCESS CONTROL OF ROPE DYEING FOR DENIM 1. Concentration of Hydrosulphite It is measured by vatometer. It should be from 1.5 gpl to 2.5gpl , or by redox potential of dye bath which should be from -730 mV to -860 mV. 2. Caustic Soda or pH value Should be from 11.5-12.5 3. Dye concentration in Dye bath it is measured by spectrophotometer. It should be in g/l Guidelines High Indigo Concentration --> Shade is greener and lighter Low Indigo Concentration --> Shade is dull and Red. High pH or Caustic Concentration --> Redder and lighter Low pH or caustic concentration --> greener and darker Dipping Time Longer the dipping time, better will be the penetration and lesser will be the ring dyeing effect. It varies from 15-22 seconds. Squeeze Pressure High pressure will lead to lower wet pick up and result in lesser color and better penetration. At rope dyeing, squeeze pressure is 5-10 tonnes, ie. wet pick up is as low as 60%. Hardness of squeeze roller is about 70-75 deg. shores. It sqeeze rolls are too hard then there are chances of slippage and uneven yarn tension.. If squeeze rollers are too soft then shading will occur. Surface of the squeeze rolls should be ground twice a year.
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Airing Time it should be 60-75 seconds. Longer airing time results in high tension on the yarn and subsequent processes will become difficult. Drying Insufficient or unevenly dried yarns will result in poor rebeaming Calculation of Replenishing Dye feed/min Conc. of stock vat is g/l= 90 range speed in yards/min=25 count = 7s totoal ends = 4100 Wt of yarn dyed /min= (4100*25*1000)/(7*840*202)= 7924 gms shade desired = 2% Amount of dye to be replenished/min= 158.5 gms Effect of pH At pH of 10.5 to 11.5, there will be formation of more monophenolate ions, which lead to higher color yield, as strike rate of the dye to the yarn bundle is very high, and wash down activities will be very good. At pH higher than this, dye penetration will be less and wash down characteristics are also poor. Testing 1. Alkalanity in Dye Bath Liquor Pipet 10.0 ml of vat liquor into 100ml of distilled water in a 150 ml beaker. place under continuous agitation and insert the electrodes of a pH meter caliberated at pH 7.0 with standard buffer solution. Titrate with tenth normal HCl ( 0.1 HCl) to pH 7.0 (ml = A) calculate g/l of NaOH = A *0.40 2. Hydro in Dye bath Liquor Add 2 ml of 37% HCHO to 150 ml beaker. Add 2 ml of dye range liquor . Add 6 ml of 41
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
25% glacial acetic acid solution prepared by diluting 1 part acid with 3 parts water. Add 2 ml of starch/KI indicator. Add ml of water. Titrate with 0.046 N ( prepared by diluting 460 ml of 0.1 N Iodine to one liter ) solution until the color changes from emarald green to bluish purple. G/l of hydro= mo fo 0.046N of Iodine Importance of High Concentration of Free Hydrosulphite The clearest shades with minimum reddish streaks are observed at by relatively high conc. of hydrosulphite. On the other side, with lack of hydrosulphite, the leuco indigo is less dissolved and thereby adheres to a greater extent to the fibres. With lack of hydrosulphite furthermore, the amount of unreduced dyestuff by oxidation at the upper level of the liquor and through activiation of unfixed dyestuff, gets separated from the fibrous material would constantly rise as the reducing agent for creating leucoform would be missing. Under these circumstances a reddish bronze like shade results due to dispersion of not reduced dyestuff in the yarn. The min. proportion of hydrosulphite should be around 1.3 to 1.5 gpl in case of rope dyeing and 3-4 gpl in case of sheet dyeing. Also to avoid the lack of hydrosulphite or Indigo at certain places in the immersion, vat, the whole quantity of the liquor should be circulated 2-3 times every hour. Reaction Time At very short reaction time, an adequate liquor exchange ( i.e. the amount of chemicals consumed and replaced by fresh addition of reduced indigo) is not assured. This has a negative influence on dyeing and depth of dye penetration. In addition to this the time available for diffusion of dyestuff until oxidation commences is too short. To ensure an even and good depth of dye penetration by dyeing in several passages, the reaction time should be 20-30 sec. for each vat (eg. at a speed of 20m/min for a reaciton time of 10 seconds, the immersion path should be maximum 3.3 meters). A reaction time exceeding 60 seconds should be avoided as the amount of dyestuff again get reduced and released may again supersede that of additionally take up dye stuff, resulting in higher shades. Softening Agent: 8 g/lit Drying: Rest humidity should be 30% and then sized. Addition of chemicals 1. Red Tinge: reduce addition of NaOH, increase slightly Na2S2O3 2. Darkish Red: increase Hydro 3. Light Greenish: decrease Hydro 4. Dark Green: Increase Caustic
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
PROCESS OF DYEING OF SULPHUR COLOR: 1st Wash tank: mercerisation by taking 22% NaOH ie. 250 gpl 2nd Wash Tank: Hot Wash 3rd Wash Tank: Cold Wash In 1st and 2nd dye bath take sulphur color 6-8% on the weight of the yarn sheet. Temperature 90 deg. cel. The solution contains the following: 1. solubalised sulphur color: 150 gpl 2. Na2S--> reducing agent: It is added to increase its reducing power 3. Caustinc Soda --> 10 gpl--> reducing agent 4. Wetting agent--> 2gpl 5. Antioxident Sulphide ( Glucose paste--> 5gpl). This is added to prevent the oxidation of of Sulphide solution. It will always remain in reduced form ( Alos if the shade is slightly greyish, one can add tiny tinge of sulpher blue--> 20gpl) in III, IV and V dye bath--> cold wash in 6th dye bath. We take H2O2(30%)+Acetic Acid(2:1 by weight). H2O2 acts as an oxidising agent. But as it acts on neutral pH (=7) and after cold bath the solution is slightly alkaline, to make it neutral wil add acetic acid. Acs in alkaline pH, oxidising action of H2O2 will be similar to the bleaching action, which may cause tendering in the fabric. 7th and 8th Dye Bath: Cold Wash Wash Box Number 4: Here washing is done with detergent and soda ash at 60-70 deg.c 5th and 6th Wash Box: Hot Wash 7th wash Box: Here softner is added at 25 gpl. It is cationic softener with pH 4.5 to 6.5. As during oxidation of sulphur, strength is reduced by 10%. On a yarn sulphur is of two types : 1. Free Sulphur 2. Reacted Sulphur. The free sulphur will react with moisture in the atmosphere to form: H2O + S --> H2SO4 Which tenders the yarn. Now at acidic pH reaction is much faster. So we add only a small amount of softener (25 gpl) as against that in indigo which is 100gpl. 3rd Point Over all during sulphur dyeing and storing, the yarn strength is reduced by 15% as compared to Indigo. 4th point If ball formation takes place of sulphur dyed warp at loom shed, then we can taken in 4th dye bath little Na2S+Caustic to reduce the free sulphur.
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
DIFFERERENCE BETWEEN SLASHER AND ROPE DYEING ROPE DYEING SLASHER Warp yarns are assembled on the ball Warp yarns are directly wound on a beam warper to form a rope. in the form of a sheet. Ropes are drawn through dyeing range Dyeing is done in sheet form side by side. After dyeing they are dried on a drum drier and deposited in cans. The ends are spread out on long chain beamer Or on a rebeamer, and the yarn sheet is wound onto warp beams. These beams are then taken to sizing. After sizing they are dried and assembled on the weaving beam. Good depth of shade is achieved In rope dyeing we have very high productivity but the limitation is that it is very expensive for short lots. It can only run for coarse yarn as the tension on rope breaks the yarn Time consuming processes are rebeaming and then sizing As the dye bath is less exposed to air so dye is affected less. The oxidation time is greater for fixation The wetting time is greater and so dye is applied uniformly The rope dyeing machine is much expensive than Slasher. Rope opening is avoided
After dyeing the warp sheet is dried on the same machine in continuous process by drying cylinders and then sizing is done on the same machine and after drying it is wound on a weaver beam Depth of shade is not good In Slasher dyeing productivity is less but it is feasible for short lots. It can run for fine yarns too Rebeaming is not required and sizing is done after dyeing. Setting up or stabilization of the dye baths is affected faster. The immersion and oxidation times are much shorter Owing to the paralleled warp threads, the wetting process is shorter and a wetting trough may be adequate. The sheet dyeing machine is smaller than a rope dyeing machine, which means that the prime costs are lower Warp sheet entanglement is a danger
DYEING IN US DENIM: The Rope Dyeing section is equipped with Morrison's Rope Dyeing Range. Morrison has more than 200 Rope Dyeing systems installed the world over, making it the globally recognized "first quality" method of indigo dyeing is the world. Dyed Lots are inspected at US Denim's in-house Dyeing Lab to ensure the fabric shade as per customer requirements. The Inspected Lots are then transferred to the ReBeaming section for further processing. Dyeing department is present on first floor. There are two working shifts in the department each of 12 hours a day. 44
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
MORRISON'S ROPE DYEING RANGE Features: Custom designed Indigo Rope Range for maximum flexibility with minimum waste Dyes multiple yarn weights with multiple dye classes Runs short or long production lots with light or heavy depths of shade Pretreatment consists of counter flow scour / wash boxes Mercerizing adds improved dye affinity, luster, strength & fashion effects Multiple dips of indigo & oxidation time in the skier section for shade depths Multiple wash boxes for rinsing & chemical application Coilers lay ropes into drums in a pattern that facilitates Re-beaming operation
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
RE-BEAMING After rope dyeing, dyed yarn is rebeamed. This is also called warper beam. Features
Heavyweight [66 tax (G 75's)] to lightweight [2.25 tax (1800's)] yarn processing capabilities High energy efficiency by utilizing AC generated power Tension-controlled motors in creel to drive the size box & head end motors Greater yarn stability through fluted rolls Precise tension control Individual beam tension control in the creel via load cell tension rolls & AC tension controlled motors Machine Layout
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
SIZING Although the quality and characteristics of the warp yarns coming out of the winding, warping and dyeing processes are quite good, they are still not good enough for the weaving process for most of the yarns. The weaving process requires the warp yarns to be strong, smooth and elastic or extensible to certain degree. To achieve these properties on the warp yarns, a protective coating of polymeric film forming agent (size) is applied to the warp yarns prior to weaving; this process is called slashing or sizing. The main purposes of slashing are as follows:
To increase the strength of the yarns To reduce the yarn hairiness that would cause problems in weaving process To increase the abrasion resistance of the yarn against other yarns and various machine elements To reduce fluff and fly during the weaving process for high speed weaving machines.
DRYING ZONE:After the size box the yarns go through the dryer section. The wet yarns are dried by using cylinder drying. Cylinder drying is done using steam heated hot rolls called the drying cylinders. The cylinders are coated with Teflon to prevent sticking of the yarns on the cylinders. SIZING MACHINE
Brand
Features
Make
Germany
Quantity
01
Modern control systems for reproducible quality and efficient handling Individual drives & precise measuring systems Pre-wetting technology significantly reduces size & increases weaving efficiency Precise sizing control Perfect beams for better weaving results Reproducible size preparation - manual or fully automatic
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
WEAVER’S BEAM:The yarns are wound on to weaver’s beam at the headstock. A pressing roller is pressing the warp yarn for uniform tension winding. A guide roller guides the yarns to the weaver’s beam. A pressing roller is pressing the warp yarn for uniform tension winding.
TRANSPORTATION OF BEAMS:After the winding of dyed warp beams the form the head stock the samples of the yarn are taken to laboratory for testing and then it is transported to the weaving department.
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W E A V I N G
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
WEAVING The process of producing a fabric by interlacing warp and weft threads is known as weaving. The machine used for weaving is known as weaving machine or loom. Weaving is an art that has been practiced for thousands of years. The earliest application of weaving dates back to the Egyptian civilization. Over the years, both the process as well as the machine has undergone phenomenal changes. As of today, there is a wide range of looms being used, right from the simplest handloom to the most sophisticated loom. BASIC WEAVE DESIGNS There are three basic weaves: 1) Plain weave
2) Twill weave
3) Satin Weave
Most of the other weaves are derived from these three basic weaves. The immediate derivatives of these three structures are warp rib, filling rib, and basket weave. 50
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
Classification of Weaving Machines: Weaving machines are classified according to their filling insertion mechanism. The classification is as follows:
LOOM
SHATTLE
SHATTLE-LESS Air-Jet Rapier Projectile Water-Jet
AIR-JET WEAVING: Air-jet weaving is a type of weaving in which the filling yarn is inserted into the warp shed with compressed air. Air-jet system utilizes a multiple nozzle systems and a profiled reed. Yarn is drawn from a filing supply package by the filing feeder and each pick is measured for the filling insertion by means of a stopper. Upon release of the filling yarn by the stopper, the filling is fed into the reed tunnel via tandem and main nozzles, which provide the initial acceleration. The relay nozzles provide the high air velocity across the weave shed. Profiled reed provides guidance for the air and separates the filling yarn from the warp yarn.
Here are some of the common fabric defects and their troubleshooting as observed on Denim weaving Airjet looms. I have included the damages observed on Tsudakoma looms, but I am sure the principles can be applied on other airjet looms also:
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
a. BENT PICK 1. Check catch cord drawing in and its position 2. Air pressure of all nozzles 3. Heald Frame height and shed crossing 4. Check stretch nozzle timing and position 5. Reed dent gap opposite to stretch nozzle. 6. Check condition and position of weft rubber stopper. 7. H1 Feeler head condition to check for any damage etc. 8. Heald frame side play to check 9. Binding of Leno Yarn b. WEFT PATTI 1. Check pressure of AGS 2. Check AGS piston 3. Check beam gear and beam drive pinion 4. Check beam bearing bush, clamper condition and beam bearing 5. Check ELO timing 7. Check tension lever rod freeness and shock absorber position 8. Check take up gear and take up belt condition 9. Check press roll spring tension 10. The machine should not be stopped for long duration c. WEFT FLOAT 1. Check Air pressure 2. Check leakage of air pipes 3. Check nozzle jet timing 4. Check catch cord end drawing in position 5. Check stretch nozzle position against reed dent gap. 6. Check heald frame height and shed crossing timing 7. Check fringe length 8. Check LHS cutter timing 9. Check position and condition of rubber stopper 10. Check proper winding of weft turn on FDP 11. Check individual subnozzles for blowing 12. Check all warp ends are tight enough 13. RH/LH selvedge should run on last ring of the temple. d. MISSING END / CHIRA 1. Check all serrated bars are not in loose contact at the clamp 2. Serrated bars should be thoroughly cleaned with petrol/thinner 3. Dropper sensitivity to be checked 4. Electric connection at the cable with clamp should be checked. 5. Remove fluff from the serrated bars 6. Ensure that each warp end is attached with one drop pin.
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
e. TORN OR HOLE AT THE TEMPLE 1. Check that temple cover is face to face with temple bracket 2. Ensure that temple bracket are fitted firmly on temple bar 3. Check heald frame height and shed crossing timing. 4. Check warp tension 5. Check bottom guide bar setting 6. Check press roll spring tension f. ABRASION MARK 1. Check position of warp stop motion separator 2. check cross ends 3. Check freeness of heald wires. 4. Check emery roll for any cuts etc. 5. Check freeness of temple rings 6. Check smoothness of temple covers 7. Bottom guide bar position and condition to be checked 8. Check reed-dent spacing g. NOZZLE MARK 1. check sub nozzle angle and height 2. Check scratches at tip of sub nozzle 3. Sub nozzles should be parallel 4. Check Reed dents h. JIRKY/ MISSING PICK 1. Check working of H1/ H2 feeler 2. Check feeler timing in I-board 3. Check setting of FU-203 (sensitivity of H1 and H2 feelers) 4. Clean H1 and H2 Feeler head i. TIGHT ENDS 1. Check that ends should be parallel 2. Remove entanglement of warp ends 3. Check that sticky ends of selvedge should not run in the body. j. OIL DAGHI 1. Check that no oily fluff is stuck to the warp sheet 2. Check that no oily fluff is stuck to the emery roll or pressure roll. k. BAD SELVEDGE 1. Check leno stop motion 2. check proper RH cutter setting 3. Check continuous working of batching winder
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
WEAVING IN US DENIM In US DENIM weaving is carried out through air Jet looms. Like some other departments weaving department is running 24 hours a day and meeting the sales requirements. Weaving department is playing a leading role in denim manufacturing at of denim at US DENIM. Air jet weaving is a type of weaving in which the filling yarn is inserted into the warp shed with compressed air. Air jet weaving utilizing a multiple nozzles system and profile reed. Yarn is drawn from a filling supply package by the filling feeder and each pick is measured for the filling insertion by means of a stopper. Upon release of the filling yarn by the stopper, the filling is fed into the reed tunnel via tandem and main nozzles. The tandem and the main nozzle combination provide the initial acceleration, where the relay nozzles provide the high air velocity across the weave shed. Profile reed provides guidance for the air and separates the filling yarn from the warp. A cutter is used to cut the yarn when the insertion is completed. Air jet machine has an extremely high insertion rate .Due to its exceptional performance, air jet machines are used primarily for the economical production of standard fabrics, covering a wide range of styles. Meanwhile, more and more special fabric segments are covered: heavy cotton fabrics such as denim, terry fabrics, glass fabrics, etc. The advantages of air jet weaving machines are: • High productivity. • Low initial outlay. • High filling insertion rates. • Simple operation and reduced hazard because of few moving parts. • Reduced space requirements. • Low noise and vibration levels • Low spare parts requirement. • Reliability and minimum maintenance. After the tandem and main nozzles are turned on, yarn is released from the clamp (stopper).When all the coils of the particular pick have been pulled off the feeder, the stopper closes the yarn decelerates and then will be beaten into the fabric. Thereafter, the air is turned off and the pick is cut to complete the cycle.
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
WEAVING MACHINE:
Features
Brand
PICANOL
Make
Belgium
Total looms
86 looms
Fast, simple width changes & symmetrical width reduction Modular feature equipped to fit a superstructure Newly designed relay nozzles & valves for highest performance Split frame for style change in less than 30 minutes Optimized insertion preparation for up to eight colors or yarn types Standard design for cam, dobby and jacquard motions Warp beam and cloth roll can be changed quickly without tools
TRANSPORTATION FROM WEAVING A doff of required length according to Let off of the loom and quality of the fabric is removed from the loom and transported to the finishing department 55
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
F I N I S H I N G
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FINISHING OF DENIM “A process done to fibers, yarns and fabric causing them to change in appearance, texture and performance.” The term finishing covers all those treatments that serve to impart to the textile the desired end-use properties. These can include properties relating to visual effect, handle and special characteristics such as waterproofing and nonflammability. Finishing treatment is done to achieve the ultimate customer requirements. These are mostly value added processes. Finishing may involve • Mechanical Finish • Chemical Finish MECHANICAL FINISHING: Mechanical Finishing is defined as any operation performed to improve fabric appearance or function by physical manipulation. Steam or water may accompany the physical manipulation; however, chemicals other than lubricants are seldom used. Fabric luster, smoothness, softness, residual shrinkage and hand are examples of the properties that can be altered by mechanical finishing. • Compacting (Shrink-proofing) • Calendaring • Raising (Napping, Sueding) • Shearing • Polishing • Corduroy Cutting CHEMICAL FINISHING: Among chemical treatments one can further distinguish between treatments that involve a chemical reaction of the finishing agent with the fiber and the chemical treatments where this is not necessary (e.g. softening treatment). Some finishing treatments are more typical for certain types of fibers like easy care finishes for cotton antistatic treatment for synthetic fibers and mothproofing and anti-felt treatments for wool. In case of fabric the finishing treatment often take place as a separate operation after dyeing. In more than 80% of cases the finishing liquor, in the form of an aqueous solution/dispersion, is applied by means of padding techniques. The dry fabric is passed through the finishing bath containing all the required ingredients, and is then passed between rollers to squeeze out as much as possible of the treating solutions before being dried and finally cured. Washing as final step, tends to be avoided unless absolutely necessary. Following are some of the Finishes: • Flat finish (singeing – mercerizing- padding- sanforizing) • Regular finish (singeing –padding- sanforizing) • Coating 57
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
FINISHING IN US DENIM US DENIM finishing department is a well-established modern section with a suitable range of the finishing processes required for denim. WORKING IN FININSHING DEPARTMENT OF US DENIM: It is divided in to following main sections:
Batcher formation Singeing Mercerizing (chemical treatment) Stenter Sanforizing
Finishing is done according to the customer` s requirement and as per profit of the organization. Singeing, skewing, washing and sanforizing are done according to end use of fabric. Parameters of the finishing are set by testing under the supervision of the finishing department. DENIM FINISHING: The finishing of denim fabric is accomplished for several purposes. The fabric is brushed to remove the loose lint, singed to burn off the hair-like fibers. The denim must be preshrunk to prevent the finished garment from shrinking after washing. The fabric is often chemical treated with size, wetting agent and lubricants. Washing a piece of unfinished fabric and measuring the normal shrinkage that occurs determine the amount of shrinking needed. During finishing the fabric is skewed to prevent the garments from skewing after fabrication. The basic denim compressive shrinking range is used in the factory that has most denim finishing in a separate denim finishing range. The machine consists of entry end, shrinking machine, drying, folding or batching.
SINGEING Singeing means burning off loose fibers sticking out of textile goods. REASONS FOR SINGEING: Common reasons for singeing include: 1. Textiles are first and foremost singed in order to improve their wear and end use properties. 2. The burning-off of protruding fiber ends which are not firmly bound into the yarns results in clean surface which allows the structure of fabric to be clearly seen. 3. Fabrics which have not been singed soil more easily than singed fabrics. 4. The risk of pilling, especially with synthetic fibers, is extremely low in case of singed fabric. 5. A closely singed fabric is essential for printing fine intricate patterns. 6. The risk of skitter dyeing with singed piece dyed articles in dark shades is considerably reduced as randomly protruding fibres cause a diffuse reflection of light. 7. Singeing process facilitates and speeds up desizing. This effect, however, is achieved only if the fabric is impregnated with desizing liquor immediately after singeing. 58
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
FABRIC BEFORE AND AFTER SINGEING
Before singeing
After singeing
TYPES OF SINGEING Singeing can be classified into two types: 1. Direct singeing 2. Indirect singeing DIRECT SINGEING is the most popular procedure. The fabric passes either glowing metal with contact (mainly for pile fabric) or a direct gas flame. Important for both techniques: when the machine stops, the fabric is moved from the metal and the flame stops, too. The indirect singeing works with highly heated ceramic modules. Infrared beams are burning the loose fibers; speed controls the singeing effect. GAS SINGEING; It is a type of direct singeing in which fabric is exposed to direct flame in such a way that it only burns the protruding fibers at the surface not the fabric. Gas singeing machine along with burner also equipped with cooling rollers to cool down the fabric and brushing zone in front and after singer. SEQUENCE OF SINGEING The singeing process contains three steps: 1. One cleaning step in front of the singer, 2. The singeing itself and 3. The cleaning step afterwards. 1. Pre-cleaning: Well prepared and cleaned fabric is a pre-condition for good singeing. The first cleaning should contain brushing and beating units to achieve the best output. Fabric heavily vibrates due to the beating bars. Dust, fibres and other residues get loosened and are extracted; fibers sticking to the surface get lifted by the brush segments presenting it in such a way that they easily can be singed-off.
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
2. Singeing: It is of utmost importance since if proper control is done here it leads to very severe damage to the fabric. The heart of any singeing machine are the burners, together with the supply and control units for the gas-air mixture. The essential conditions to prevent fabric damage and singeing faults are: a) A high energy flame (mechanical and thermal) to burn polyester with any residue b) A uniformly hot and hard flame to prevent singeing marks c) Machine design that minimizes flame/fabric contact time and keeps thermal energy away from the ground as much as possible to avoid thermal effects. Burner should be such that it gives oxidizing flame so that there are no soot marks on fabric. Oxidizing flame or blue flame is only possible if there is proper mixing of the fuels [Normally it is mixture of air and oxygen (3:1) 3. Post cleaning: A second cleaning after the singeing unit ensures that ashes and other products resulting from singeing are separated from the system. Cleaning after singeing is as well of importance, impregnating liquor remains cleaner and reduced amount of dust in the following process steps. SINGEING PARAMETERS: Fabric speed (m/min) Flame intensity (mbar) Fabric temperature (C) Singeing positions Burner fabric distance (mm) SINGEING FAULTS Common singeing faults are as follows: Uneven singeing effect across the fabric width along the fabric length in the form of horizontal and/ or vertical steps Thermal damage of the fabric or individual fibre types within the fabrics e.g., formation of beads of molten material in polyester.
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
SINGEING MACHINE IN US DENIM: In US Denim one Singeing machine of OSTHOFF is installed. Manufacturer: Osthoff Singeing - Goller Desizing Year 1997-98 Fabric Width 103" / 2600mm Roller Width 108" / 2800mm Rotation Stations: Hydraulic Rotation Station Motorized Rotary Total 14 points Machine Configuration Batcher / Plaited Stack Singeing Compartment, 2 Burners, 15 mbar Pressure both side adjustment Desizing Compartment, 5/6 Top and Bottom Roller, approx 22m cloth content Batcher at exit
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MERCIRIZATION It is the process by which natural twist / convolutions are open by the help of concentrated alkali under tension conditions. It is a treatment which makes the cellulose start to swell at a certain alkali concentration. Advantages of Mercerization: improves dye uptake up to 40% permanent luster is obtained improves tensile strength dimensional stability dead cotton coverage less pilling effect The advantages of mercerization are considerable. The increase in the dye uptake capacity results in deep shades and expensive dyes savings can be achieved. Furthermore as a rule, the color fastness and uniform appearance of goods are also improved.
Concentration of NaOH is very important 29-30° Bome of NaOH Cold water is used i.e. 15-18°C is ideal temperature for mercerization or maximum room temperature. pH should be in alkaline range
Since mercerization affects the dyeing properties, any irregularities have a direct effect on the dyeing or print. The result of inadequate mercerizing are: unleveled dyeing reduced color fastness properties ending or cross shading varying dimensional stability inadequate coverage of dead or immature cotton alkali marks SEMI-MERCERIZATION: Sometimes when we are in need of light shades than mercerization is done on a small scale by applying less caustic to the warp sheet. PRE-WASHING: After mercerization pre-washing of the warp sheet is done. Once the sheet is washed by hot water and then cold water. Pre washing is done in order to remove the excess pretreatment chemical from the warp sheet. If they remain inside the sheet than it will cause the fibers to loose and also dyeing will not occur uniformly. Squeezing rollers are provided at the end of each bath to remove the excess liquor from the sheet. These rollers also drive the warp sheet. Pressure on these rollers is adjusted according to the tensile strength of the warp sheet with the help of load cells. Clod washing is done after hot washing in order to reduce the temperature of the warp sheet. 62
PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
MERCERIZING MACHINE IN U S DENIM Manufacturer: Goller Year 1997-1998 Refurbished in 2004 Fabric Width 70" / 1800mm Roller Width 79" / 2000mm Dwell Time in the mercerizing section 35 second Speed 45 m/min Mercerizing Section 18 pairs of rollers, cloth content in mercerizing machine 30-35m, Stabilizing Section 18 pair of rollers, cloth content in stabilizing machine 30- 35m No of Washing Compartment 5 Cloth Content 22 x 5 = 110 meters Can Dryers 12 Machine Configuration > Batcher / Plaited Stack > Scray > Wet on Wet Mercerizing Arrangement (trough and padder) > Mercerizing Section (Chiller option included) > Stabilizing Section > 1 Modified Turbo Washing Compartment with 2 suction sloth, 22m cloth > 4 Normal Goller Washing Compartment 22 meter cloth > Drying Cans > Scray > Batcher
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
STENTER:The stenter is a gas fired oven, with the fabric passing through on a chain drive, held in place by either clips or pins. Air is circulated above and below the fabric, before being exhausted to atmosphere. As well as for drying processes, the stenter is used for pulling fabric to width, chemical finishing and heat setting and curing. It is a very versatile piece of equipment. Modern stenters are designed with improved air circulation, which helps to improve drying performance, and with integrated heat recovery and environmental abatement systems. Infra-red drying is used for both curing and drying. It is used as either a stand alone piece of equipment or as a pre-dryer to increase drying rates and hence fabric speed through a stenter.
Stenter ALKAN Year 2001 Location Turkey w/width 2400mm, Horizontal.pins clips chain ( Combi) 6 chambers, diathermic oil heating, Squising padder with 2 cylinders with impregnation tank, Corino electronic weftstraightener, collector at the entrance, air cooling at the exit, entrance and exit on big roll or folder.
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
SANFORIZING OBJECTIVE OF SANFORIZING The sole objective of sanforizing is to control the length wise shrinkage of fabric. The maximum percentage of shrinkage depends on fabric construction and quality but controlled according to the customer specifications. CONTROLLED COMPRESSIVE SHRINKAGE PROCESS The internationally well-known and most important shrinking process today dates back more than 70 years. Though the correct expression for this process is Controlled Compressive Shrinkage, the average person knows it as SANFORIZED. The process is a purely mechanical treatment without any addition of chemicals. The Sanforized label means dimensional stability for garments made up of Sanforized labelled fabrics. The purpose of the process is to shrink fabrics in such a way that textiles made up of these fabrics do not shrink during washing. The amount of potential wash shrinkage must be determined prior to shrinking. A full width sample is wash-tested according to the test method. After the lengthwise and widthwise shrinkage has been determined, the compressive shrinkage machine can be adjusted accordingly.
Monforts Sanforizing Range Manufacturer: Monforts Year 1997-98 Fabric Width 1800mm Roller Width 2000mm Shrinking Cylinder 640 mm Moisturizing Unit Monforts Palmer Unit 2 meter Rollin Rubber Belt
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
MACHINE CONFIGURATION > Batcher / Plaited Stack > Scray > Moisturizing Unit from Monforts and Steaming Can > Shrinking Unit Rollin Belts > Palmer Unit > Scray > Batcher
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
I N S P E C T I O N D E P A R T M E N T
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PROJECT REPORT_______________________________________________________________________________________________________ PRESTON UNIVERSITY
INSPECTION Quality is ultimate concern; every single yard of the denim goes through inspection department and rated by a point count system to ensure that quality is up to standard before packing. Defective fabric pieces are rejected and sold as seconds and relatively minor defective points are marked clearly using stickers to alert cutters
Defects • Removable defects • Non-Removable defects REMOVABLE DEFECTS Removable defects are those defects which are removed by washing and by cutting. Defects are:
OIL STAINS When fabric gets spots of oil lubrication from any part.
SLUBS It is the collection of the threads at the surface of the fabric. Similarly fibers present in the form of bunch at the fabric are called slubs. This defect is removed by combing.
HOLE When fabric passes through temple it produces holes on the fabric due to its wiry surface.
NON REMOVABLE DEFECTS Those defects which cannot be removed by mending and these are count in fabric grading. These are: JALA In warp and weft direction there is a gap, it looks like that some warps or wefts are missed. CRACKS During weaving when m/c stops and again starts running then there is a gap between the two wefts. It seems like that the beating is not done properly. PATTI It is the dark color or thick weft lines in the fabric.
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DOUBLE PICK The two or more threads are inserted at the same place. It is somewhat emboss and occur at the full length of the fabric. BROKEN PICK If the double or thick yarn is inserted 1/4 or ½ width of the fabric then it is known as cut or broken pick. BROKEN END When the warp end is broken. KNOT It comes due to knotting of broken warp end. FINGER MARK It comes when a person touches the warp ends. CREASE MARK Creases occur due to improper finishing. WRONG DENTING When more yarns are passed through dents. TIGHT END When warp end becomes tight due to tension in dyeing. COARSE END It comes when warp end is coarse. MISS PICK If the weft yarn is missing from any place of fabric then it is known as miss pick. REED MARKS The lines are formed on the fabric due to reed movement and this defect is called reed marks. STARTING MARKS That mark which is due to the beating motion of the loom is called starting mark.
A GRADE FABRIC If 30 points come in meter fabric it is considered as A grade fabric.
B GRADE FABRIC If more than 30 points comes in fabric then it is considered as B grade fabric. 69
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PACKAGING In the packaging section, fully inspected A-Grade fabric is packed as bale or roll according to customer requirements. Shipping marks are also printed on the packaging using computerized ERP labeling software.
P A C K I N G
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FAULTS OF WARPING FAULTS IN MACHINE: • Stop motion does not work on creel and on warping drum as a result broken ends are not traceable for knotting. • Chain breakages • If frictional drum should not be kept in a polished state, then thermal damages occur due to abrasion. • Brake could be inefficient. • Sprockets are jammed. • If comb do not move properly then there is a chance of cutting of comb due to friction with yarn. • Tension supplied if varied it causes breakages or loosening in yarn. • If speed of warper increase than yarn sheet may break FAULTS IN RAW MATREIAL • Neps • Long thick places (in case of non slub yarn) • Short thick places (in case of non slub yarn) • Thin places • Weak places • Count variation • Hairiness FAULTS IN PRODUCT: • Misalignment of yarn sheet if the yarn sheet is not properly adjusted • Uneven package density • Too soft package winding • Package could not be in uniform density
FAULTS OF DYEING FAULTS IN MACHINE: • Leakage of steam in drying cylinders • Wear and tear of rollers if bearing is jammed • Improper working of load cell on squeezing roller. Which causes entanglement of warp sheet as pressure is not properly distributed • Faults in dosing system can cause serious problem of shade variation. • If the accumulator do not work properly than the machine is stopped. • If speed of the machine is kept greater than the yarn‘s bearable strength 71
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FAULTS IN RAW MATERIAL: The main causes of the dye ability variations in yarn are: • Immature fibres • Dead fibres • Vegetable matter or other foreign matter • Wrong twist • Bad splice • Neps • Count variations
SIZING FAULTS • Pressure rolls do not work properly • Squeezing rollers do not work properly
WEAVING FAULTS • Dropper will not fall • Sensors do not work properly • Problem in electrical panel • Problem in electronic card • Wear and tear of temple • If dust comes in nozzles • Improper working of solenoid valves
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US Apparel & Textiles (Pvt.) Ltd. Is the foremost garment manufacturing company of Pakistan with 3 Factories and more than 30 years of experience behind its back. We are fully capacitated to handle any volume orders. Weaving, Cutting, Stitching, Embroidery, Washing /Special effects and Packing are all dealt with in house according to “ISO-9001:2000” and “WRAP” certified standards. For many years major US, European and UK retail stores and mail order companies in Europe have counted on our quality, making US Apparel & Textiles a fully vertical and specialized textile company.
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C U S T O M E R S
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STORAGE:
U S D E N I M
Instead of relying on a single in-house fabric source; US apparel has invested in an impressive warehouse facility stocks up to 1.2 million meters of fabric at all times, plus a host of garments related accessories acquired from the renowned world wide suppliers. U S Apparels stores fabric in latest “fabric storage racks” The total storage capacity is more than one million meters for fabrics alone. In addition to this, the material management store at U S Apparel stocks bulk button, stitching threads and labels; we also keep spare key machines for stand by purposes.
S T O R E R O O M
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CUTTING DEPARTMENT
C U T T I N G
To retain its flexibility U S Apparel has evolved systems to provide optimal services to broad spectrum of multi product based customers. We have also invigorated our cutting department with the addition of the most modern GERBER fully automatic fabric spreader and vacuum tables.
D E P A R T M E N T
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PATTERN MAKING
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Gerber Automatic Cutting Machine
The GERBER S-91 high-ply cutter provides users with benefits of speed, flexibility, and accuracy - in addition to saving fabric and labor. Up to 76 mm (3 inches) of compressed fabric can be consistently and accurately cut, utilizing Gerber's high-efficiency vacuum hold-down system. Cutting precision is assured with features such as automatic knife sharpening and Knife Intelligence, which automatically accommodates for blade deflection and variable knife-speed control. The S-91 is the most reliable cutter for highvolume, high quality cutting, ideal for heavy duty materials such as denim.
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Embroidery Machine
E M B R O I D E R Y
Tajima (Japan) Place of origin: China Model No: TLC-602/612/620/624/902/906/908 Payment Terms: T/T, L/C, D/P Supply Ability: 1,000sets/year
D E P A R T M E N T
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STITCHING DEPARTMENT
S T I T C H I N G
One of the biggest reasons of U S Apparel’s success has been its commitment to invest in the future while not forgetting the tried and tested. Today U S Apparel is a fine blend of traditional yet optimized production techniques, plus the most advance computer aided SMV production management system. U S Apparel is unique in its size and scale in the comparison to other companies considering its multidimensional approach.
D E P A R T M E N T
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STITCHING MACHINE Juki DDL-8700 High-speed Single Needle Straight Lockstitch Industrial Sewing Machine with Table and Motor
Juki DDL-8700 High-speed Single Needle Straight Lockstitch Industrial Sewing Machine with Table and Motor Product Details JUKI DDL8700 is a newly designed unique lockstitch machine, which perfectly matches clothing, plants for creating the 21st century fashion. The optimum-balance and highly rigid machine head were created using the latest 3DCAD design technology. Thanks to its low vibration and low noise feature, the machine head provides the operator with a comfortable work environment. In addition, the distance from the machine arm to the needle on the front of the machine head is sufficiently wide to allow easy handling of the sewing material. The machine inherits the desirable features, such as high-speed stitching performance 5,500rpm, extreme stitching performance, ease of operation, and reliability, from the highly evaluated previous JUKI lockstitch machines. (DDL-87007: 5,000rpm)
Sewing mechanism that demonstrates outstanding responsiveness to materials to be sewn. By thoroughly investigating and modifying the sewing mechanisms in order to achieve low-tension sewing, the machine flexibly responds to various kinds of materials and produces beautiful seams of consistent quality. 81
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Maintainability was improved. Enhanced maintainability is ensured by the improved machine head, such as incorporation of an eccentric pin that is used to adjust the feed dog. In addition, the machine is provided with a mounting seat for attachment to improve workability while replacing the attachment and increasing the durability of the machine bed surface.
The machine has easy-to-operate functions to achieve improved operability. By providing a presser foot with a higher lift (13mm), a light-touch stitch dial, a throat plate with marker grooves that can be used as guide for seam allowance, and other easy-tooperate functions, the burden on the operator is lightened, and productivity is further increased.
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SEWING Good sewing, good pressing, well finished ends and corners, lightness of touch which holds the work without apparently touching it, thus giving to the finished garment a fresh look–all these are important considerations. Plain stitches • • • • • • • •
basting, running, the running and back stitch, half back stitch, back stitch, overhand or whipping stitch, overcast, hemming, and Blind or slip stitch
Ornamental stitches • • • • • • • • • •
outline, chain, cat or herringbone, blanket or loop, feather, coral or briar, hemstitching, French knots, button hole Cross stitch. The satin stitch
Plain stitches (1) Basting proper is used only in the preparation of work to hold the stuff and lining, or any two or more parts of the work together while it is being stitched, none being left in the finished garment. It is also used as a guide for sewing, feather stitching, etc.
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Even Basting 1. Even basting is used for marking purposes and for very particular fastenings, such as important seams. The stitches should be very carefully taken. 2. Always knot the end of the thread; use No. 40 or 50 with a 5 or 6 needle. 3. Begin at the right-hand end of the work, passing the needle through the material or materials from the upper side. Take a stitch underneath the exact length you want all succeeding stitches to be and bring needle up again through the material. For all ordinary purposes make your stitch about one-half inch long. 4. Place the needle again through the material at the same distance from where the thread came through as the stitch underneath is. Take another stitch the same length as the one previous, and continue until the whole length of the material is basted.
Uneven Basting 1. Uneven basting is used for very much the same purpose as even basting, except that it is more often used to hold together temporarily edges of material that are later to be permanently sewed together. It is used most commonly in turning hems.
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2. Begin in the same way as you did for even basting, but instead of taking a long stitch underneath, take a short one of about one-quarter of an inch. 3. Bring the thread out and draw it over about an inch before taking another short stitch. In other words, make a long stitch on top and a short one underneath.
(2) Running is closely related to basting. It is not used for any seams that have to bear great strain, but for joining seams in this material, gathering, tucking, making cords, etc. The stitches are usually of equal length on both sides. Take one stitch in the seam and hold the goods between the thumb and first finger of each hand, as shown in the illustration, with the back of the thimble on the eye of the needle. Then, with as free wrist motion as possible, run or shake the needle through the material. The motion of the hand should come from the elbow joint. Gathering, gauging, casing, etc., are used for drawing up the fullness of skirts, ruffles, flounces, etc., into a given space. The running stitch is used for these. (3) The running and back stitch is made by taking a few running stitches, drawing out the needle and making a back stitch over the last running stitch to strengthen the seam. Care must be taken not to hold the side next the worker too full and not to miss the under material, but to take the stitches even on both sides.
(4) The half-back stitch is made by taking one stitch and placing the needle half way back, then bringing it out twice the length of the stitch and placing the needle half way back each time from where the last stitch ended. The appearance on the right side will be of regular space as in the running stitch. (5) The back stitch is made by placing the needle back to the last stitch, bringing it out once the length of the last stitch, then placing the needle back into the last stitch, and so on, making the stitches follow each other without any space between. This is used in all places that are to bear great strain.
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(6) Overhanding, oversewing, whipping, top sewing are one and the same–small stitches taken over edges, to join folded edges or selvages, for sewing bands on gathers, sewing lace and insertion, and for sewing carpet strips together. The pieces for an overhand seam should be pinned carefully, placing the pins at right angles to the edge. The folded edges or selvages are placed together, the right side of the goods being in. Do not use a knot to begin sewing, but leave the knot end of the thread and sew it in with the first stitches, carrying the thread on top of the seam. To finish off the seam, overhand back over the last few stitches. (7) Overcasting is a slanting stitch used to keep raw edges from ravelling. This stitch, like Oversewing may be worked from right to left or from left to right. (8) The hem stitch and blind or slip stitch will be considered under hems.
ORNAMENTAL STITCHES Never use a knot in any embroidery, but start by running a few stitches along the line which is to be covered. (1) The outline stitch is the simplest of all embroidery stitches. Take a long stitch on the surface, with the needle pointing towards the chest in the line to be covered, and a short back stitch on the under side of the material. The effect of the under or wrong side of the mate-rial is exactly that of an ordinary back stitch. The beauty of this stitch depends upon its regularity and in always keeping the thread on the same side of the needle.
(2) The chain stitch when perfectly done should look like the stitch made by a singlethread machine.
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This stitch is made by taking the thread toward the worker, and before the needle is drawn out of the cloth the thread is held by the thumb under the point of the needle, as in a buttonhole, making a loop. The needle is inserted in the last loop for the next stitch. The chain stitch is used in modern embroidery as an outline and for darning, but in old embroidery, the outline and chain stitches were used for filling as well. They are found in Persian, Indian, and Italian Renaissance work. Like the feather stitch, the chain stitch is worked towards the worker.
(3) The cat stitch or herringbone stitch is an alternate slanting back stitch, the needle being placed first to the right and then to the left. This stitch must be worked evenly to be effective. It is used to finish flannel seams and hems, fasten down linings, opened seams, and canvas facings and featherbone, in millinery– in fact, this stitch is one of the most useful in sewing. The -catch- stitch is a variation of the cat stitch. Instead of pointing the needle towards the chest, the stitch is taken parallel with the chest. It is used for about the same purposes as the cat stitch. As with the outline stitch, the cat stitch is worked -fromthe worker. (4) Blanket or loop stitch, used to ornament the edge of blankets, etc., and for finishing the edge of stockinet or web material, is worked from left to right, the edge of the material being held towards the worker. Start with three or four running stitches along the edge so the line of stitching will cover them. Insert the needle the desired width from the edge, draw it towards you down over the thread, being careful not to draw the thread too tightly over the edge of the flannel. Fasten the thread by taking running stitches under the last blanket stitch on the wrong side.
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(5) Single, double, and triple feather or coral stitches may be made very ornamental and are used in all kinds of sewing and on all materials. They are always made towards the worker, the stitches being taken alternately to the right and left of the line of the design. The thread should always be carried under the needle as in a buttonhole stitch. The design may be varied by taking the stitches diagonally or straight, by making them close or separated, etc. (6) Hemstitching is used for ornament in making hems and tucks. The first step in hemstitching is the drawing of threads. Rubbing the cloth along the line of threads to be drawn will make the drawing easier if the cloth is sized. After the threads are drawn, the hem is turned and basted even with the lowest edge of the drawn space. Insert the needle into the edge of the hem and material, taking up a cluster of threads bring the thread under the needle to form a buttonhole stitch or make a simple stitch in the edge of the fold. The number of threads drawn and the number in a cluster must be determined by the coarseness or fineness of the material, the greater number being drawn and taken in fine material. There are several methods of hemstitching, but the results are about the same. (7) French knots are used in connection with other stitches for borders enclosed in outline and chain stitches, in initials, centers of flowers, and as a filling-in stitch. The simplest method is of taking a small back stitch, bringing the thread from the -eye- of the needle under the point from right to left and drawing the needle perpendicularly from the cloth. Place the needle back of the knot and bring the point out in the place where the next knot is to be made. The size of the thread will determine the size of the knot. (8) The embroidery buttonhole stitch has many possibilities and many variations. It is worked from left to right instead of from right to left as in a buttonhole. The thread from the work is carried under the point of the needle from left to right, just the reverse of the buttonhole. This stitch is used on flannel and in embroidery of all kinds; it may be padded or worked flat and the stitches may be taken a distance apart or near together.
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(9) The cross stitch is worked on linen, scrim, canvas, or any open-meshed material. If done on a flat, smooth surface, it will be necessary to work over canvas, afterwards drawing out the canvas threads. The canvas should be well basted on the material, the warp threads of the canvas lying -perfectly straight- on a line with the warp threads of the material on which the pattern is worked. The stitches should always run the same way. If the first ground stitches are made from left to right, from bottom towards the top, the cross stitches should be made from right to left from the top towards the bottom. All the ground stitches run one way and the cross stitches in the opposite way. This stitch is used for marking table linen, underwear, and embroidery designs. When marking linen and unlined work, make the under side very neat by running the thread under the stitches already made, instead of taking a long stitch when beginning in another part of the letter or design. (10) The satin stitch is an over and over stitch and is used on materials of all kinds for marking linen, etc.
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HEMS A hem is a fold of goods twice folded to protect a raw edge.
Sewing Hems In sewing the hem, the needle should take up only the edge to be hemmed down and just enough to hold on the cloth or lining. In white work the stitches should be fine, showing as little as possible.
I found this fabulously perfect way to hem jeans on the Cavaricci site, which has since been taken down, so here’s the lowdown. This method keeps the original hem in tact and is especially helpful now that all jeans are made to be 34 inches long for mammoth supermodels. Plus, it took less than 30 minutes.
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A couple notes: It’s best to do one leg at a time, so as not to have too much undoing to do in case something goes awry. Also, it’s good to know the length that you want each leg to be. Sometimes, one leg will be a bit shorter or longer than the other before you hem. Step 1: Decide how much length you would like to take off. Divide that number in half. (Hems should fall just below the bottom of your ankle. Also, if you generally wear high heels, or a certain height of heel, you might want your hem a bit longer - it should fall an inch to a half inch above the floor at your heel.)
Step 2: Cuff the jeans. I wanted to take two inches off my hem, so I measured one inch out from the original hem line and pinned. (Do not include the distance from the hem to the end of the jean in your calculations.)
Step 3: Pin around the rest of the cuff, taking care to measure each time you pin.
Mind the seams while you’re pinning. Make sure that the stitching lines up at each seam.
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Step 4: It’s time to stitch. You want to place your needle and continue sewing right next to the original hem. Stitch on the right side of the hem, or the side farthest from the bottom of the jean. Sew all the way around the cuff. Be sure you don’t sew through both front and back sides of the jeans (making it so that the foot hole is sewn shut)!
You can either cut the excess off, leaving about a half inch for fraying, or iron the extra material in.
Turn the leg right side out and press the new seam flat, revealing the old hem.
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WET PROCESSING:
W E T
U S Apparel has one of the most modern garment wet processing facility in the country. The electric mix of Italian, Spanish and Far Eastern equipment allows U S Apparel to provide its customers an almost infinite range of garment washing/dyeing facility. Computerized control over wash process allows U S Apparel to give consistent wash quality in long running or repetitive production requirements. Wet process department performance is further cemented with the support of extensive computerized database and a well equipped laboratory.
P R O C E S S I N G
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WASHING MACHINE Machines suitable for all types of washing processes, such us stone washing, bleaching and other washing treatments on garments of different materials (cotton, linen, viscose, tensel treatment etc). Particularly indicated for the treatment of jeans, they are supplied with baskets provided with special beaters, speeding up the process and guaranteeing at the same time uniformity in the treatment and softness to the denim fabric. They have variable speed and are equipped with an industrial B&R PC and a PLC Mod. PP 200. The software, and in particular the “Wash program”, entirely worked out by Tonello’s engineers, allows to manage and to control all the functions of the machine as well as the process operations. It is possible to store up to 500 recipes (with 200 steps/each).
G1 420 LS EV1 Made in Italy Patented
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Technical Data Cylinder Volume Cylinder Dimensions Variable Speed Installed Power Dimensions Height Width Depth Weight
G1 420 LS EV1 4180 l Ø1890x1490 mm 0/110 rpm 17 kW
2600 mm 2940 mm 3100 mm 4400 kg
Tupesa Tumble Dryer Steam heated dryer
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CHEMICAL SHEET Commonly used chemicals
1 2 3 4
5 6 7
8 9 10 11 12 13 14 15 16 17
18 19 20 21 22 23 24 25 26 27 '18
DESIZER ABS( ECOZ) RAP ENZYME VALUMAX A
DENELITE SILICON ! BLEACH SODIUM > SODA ASH ]j CAUSTIC I HYDROGEN ACETIC ASID ISPS LYOGIN SALT STONE SOFTNER ORANGE 2 GL GOLDEN YELLOW RED REDBA ORANGE RSN BLACK NF BROWN AGL BROWN RBL LEECO DRLMAREN RED CL5B VAVYCL YELLOW CL 2R KMNO4
1
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US APPAREL & TEXTILES (PVT)Ltd. SYSTEM OF WASHING
Process Recipe Sheet Date:
Article no Wash type Color
30/5/2008 Customer Levi, s 550+505 Light Wash Total Qty (pcs): Light Blue
140 PCS Total Weight (kg): 110kg
Process & Standards: SrNo
1
Porcess
Desiring
Chemical Name
Weight gm.kg.
Desizer
1000ml
RAP
1000ml
Ni
400ml
Water Level • Time Itrs Minutes
Temp "C"
800 Llr
10 min
60 C
2
Simple Rinse 1
lOOOLtr
2 min
R.T
3
Simple Rinse2
lOOOLtr
2 min
R.T
4
Enzyming
700 Ltr
70 min
55 C
Enzyme
1500gms
RAP
1500Ltr
5
Simple Rinsel
lOOOLtr
2 min
R.T
6
Simple Rinse2
lOOOLtr
2 min
R.T
7
Soda
1000 Ltr
5 min
50 C
8
Simple rinsel
lOOOLtr
2 min
R.T
9
Simple Rinse2
lOOOLtr
2 min
R.T
10
Bleaching
11
Simple Rinse Neutral
12
Soda Ash
Bleach
Sodium
1 kg
Per/Sample
2.5kg
lOOOLtr 1000 Ltr
2 min
R,T
800 Ltr
5 min
R,T
Simple Rinsel
1000 Ltr
2 min
R.T
14
Simple Rinse2
lOOOLtr
2 min
R.T
15
Softning
700 Ltr
5 min
50 C
2Ltr
Orange LSN
2.2 gms
Brown AGL
2Ltr
L.R
50 C
13
Softner
PH
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CHEMICALS 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 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
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ANTI BACK STAINING AGENT(Kieralon_ F-ALB) Multifunctional, low-foaming wetting agent and detergent with emulsifying and extractive action for mobilising and removing cotton impurities in pretreatment processes. Quantity 4g/l Chemical nature Mixture of sequestering agents and surfactants. Physical form yellowish, clear liquid. Shelf life Keralon F-ALB can be kept in the original sealed containers at temperatures between 0 °C and 35 °C for at least 24 months. Once containers have been opened, the contents should be used up quickly. Containers should be closed tightly after use. PROPERTIES Viscosity Approx. 60 m.Pas at 23 °C (LVT, sp. 1, 50min-1) Freezing point Approx. –5 °C Density Approx. 1.0 g/cm3 at 20°C. pH Approx. 1.5 – 2.5 ( 100 g/l in water) The values given are approximate. Tolerances are given in the product specification. Stability In the concentrations at which it is normally employed, Kieralon F-ALB is stable to hard water, acids, reductive and oxidative bleaching agents, and in caustic soda of up to 250 g/l NaOH 100% at room temperature. Between the range of 90-130 g/l of NaOH 100%, please note the homogeneous gap. Solubility Soluble in cold water. Action Low-foaming wetting agent and detergent with emulsifying and extractive action for mobilising and removing cotton impurities. APPLICATION Washing Extraction of hard-water salts and pectins. Desizing Softening hard water and extracting catalytic substances. Note: no adverse effect on enzyme activity when pH is adjusted to 6-7 Boiling-off Removal of fiber impurities, removal of degraded size. Oxidative desizing Removal of fiber impurities. Bleaching Prevention of precipitation of alkaline earth carbonate. For preventing deposits. Improves the stabilizing action of conventional peroxide stabilizers.
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Cold bleaching Softening hard water, inactivating catalytic substances; improves the stabilizing action of conventional peroxide stabilizer. Scouring Improvement in handle and absorbency with shortened pretreatment methods. Recipes Notes on formulating liquors: Kieralon F-ALB should be stirred into the liquor. Washing 1 -- 3 g/l Kieralon F-ALB 0.25 -- 2 g/l Soda Temperature: 70 – 95 °C Desizing … g/l Luzyme MT 2 -- 3 g/l common salt 2 -- 5 g/l Kieralon F- ALB 1 g/l Leophen® FR-M (pH 6 – 7 ) Impregnation temperature: 60 - 70 °C Liquor pick-up: approx. 100% for Co approx. 70% for PES/Co dwell time: approx. 4 – 5 hours Boiling-off 30 -- 50 g/l NaOH 100% 3 -- 5 g/l Kieralon F- ALB Impregnation temperature: 20 - 80 °C Liquor pick-up: approx. 100% for Co approx. 70% for PES/Co. Steaming temperature: approx. 100 °C Steaming time: 5 – 20 minutes (e.g. combination steamer, U-box) Oxidative desizing/boiling-off 30 – 50 g/l NaOH 100% 2 – 3 g/l Persulphate 3 – 5 g/l Kieralon F-ALB Impregnation temperature: 20 – 40 °C Liquor pick-up: approx. 100% for Co approx. 70% for PES/Co Steaming temperature: approx. 100 °C Steaming time: 5 – 20 min (e.g. combination steamer, U-box)
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Bleaching with Hydrogen peroxide 1. Bleaching of desized and alkaline-pretreated fabrics 20 – 50 ml/l hydrogen peroxide 35% 4 –5 g/l NaOH 100% 8 – 12 ml/l Prestogen® PL 2 –4 ml/l Kieralon F-ALB Impregnation temperature: approx. 20 °C Liquor pick-up: approx. 100% for Co approx. 70% for PES/Co Steaming temperature: approx. 100 °C Steaming time: 15 – 20 min (e.g. combination steamer, U-box) Cold bleaching with Hydrogen peroxide 40 – 50 ml/l hydrogen peroxide 35% 10 – 25 g/l NaOH 100% (7 – 15 g/l sodium silicate 38 ° Bé) 8 – 12 g/l Prestogen PL 3 g/l persulphate 3 – 5 g/l Kieralon F-ALB 1 g/l Leophen FR-M Impregnation temperature: approx. 20 – 40 °C Liquor pick-up: approx. 100% for Co approx. 70% for PES/Co Dwell time: 16 – 24 hours Scouring 2 g/kg Lufibrol® MSD 1 – 2 g/kg Kieralon F-ALB Temperature: 80 – 95 °C
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DISPERSING AGENT(SETAMOL_ BL) All purpose liquid dye dispersing agent. Quantity 2g/l Nature Sodium salt of a condensation product of naphthalenesulphonic acid and formaldehyde, anionic. Physical form Brown, mobile liquid. Storage When stored correctly, in sealed containers, Setamol® BL has a shelf life of upto 24 months. PROPERTIES Density approx. 1.16 g/cm3 at 20 oC pH approx 9-10 (10% solution) Solubility Infinitely soluble in water Boiling point From approx. 100 oC Stability Setamol® BL is stable to acids, alkalis, hard water and electrolytes and retains its high efficiency even under HT dyeing conditions. Compatibility Because it is anionic, Setamol® BL has good compatibility with all anionic and nonionic products. In combination with cationic auxiliaries, e.g. Peregal® P, precipitation may occur in neutral or acid liquors, but not under alkaline conditions. Action Setamol® BL improves the stability of dye dispersions. It prevents agglomeration and improves the solubility of many dyes. Setamol® BL has no wetting action or, detergency and practically no retarding effect on vat and disperse dyes. The product has affinity for animal fibres and polyamide, especially in acid liquors. Application Setamol® BL can be added direct to the dye liquor. Vat dyes Setamol® BL is ued to improve the stability of stock vats and when vatting is carried out in a long liqour. An addition of Setamol® BL is definitely recommended when vatting highly concentrated powder and paste-type dyes, which contain only a small amount of dispersing agent. In the oxidation of vat dyes, Setamol® BL prevents filteringout of the insoluble dye pigment, which if formed in the bath by oxidation of the residual vat dye.
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Amounts used: Stock vat : 5-30 ml/I Long liquor : 5- 6 ml/l In the oxidation bath : 1- 3 ml/I Anthrasol dyes Because of its good dispersing action, even in acid liquors, Setamol BL® prevents the precipitation of loose dye and the consequent risk of stains when dyeing is carried out by the two-bath process. The product is used both in the continuous dyeing procedure and during development in jigs, winches or circulating-liquor machines. One-bath process : 1-3 ml/I Setamol® BL Two bath process : 1.5-5 ml/I Setamol® BL Disperse dyes Setamol® BL is widely used as a dispersing agent in the dyeing of manmade fibres, e.g. acetate, triacetate and polyester, with disperse dyes. It also retains its full efficiency. under HT conditions (120-140 oC). The amounts used are largely dependent on the liqour ratio, e.g.: in winches, soft-stream machines and jets 1-3 ml/l in beam and yarn-dyeing machines 1.5-5 ml/l in jigs 3-6 ml/I Setamol® BL prevents agglomeration of the residual dye particles in the liquor when the dyebath is cooled down, and thus ensures good rubbing fastness. Napthol As dyes 3-6 ml/I Setamol® BL is added to stabilize Naphtol AS padding baths.
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ANTIMICROBIAL FINISHING OF CELLULOSIC FIBER MATERIALS (DENIM) Product description REPUTEX 201 is a product for the durable antimicrobial finishing of cellulosic fiber materials. It contains the active substance PHMB, which very effectively inhibits the growth of odor-causing and pathogenic microorganisms. As with all biologically active substances, special rules must be applied when handling REPUTEX 20 and using it in the textile industry. These concern industrial safety, safe disposal and appropriate treatment of waste water. For Denim Ph 6 to 6.5 Temperature 35°C to 40°C Application on cold conditions Properties Nature 20 % aqueous solution of poly(hexamethylenebiguanide hydrochloride), PHMB Structural formula
with n = 16 (average value) CAS name Poly(hexamethylenbiguanide) hydrochloride, 20 % in water Physical form Slightly hazy, colorless, odorless low-viscosity liquid Storage REPUTEX 20 has a shelf life of approx. 2 years when stored at a pH of 6 – 8 and a temperature of 25 °C. Storing the product at temperatures that differ significantly from 25 °C may reduce the shelf life. The product should be stored in the original sealed containers. It should be protected from temperatures below 0 °C and above 40 °C. The product must not be stored together with strong bases, hypochlorites or strong oxidizing agents. Product specification The values below are approximate. Tolerances are given in the product specification. Viscosity (25 °C) Approx. 5 mPa · s pH (25 °C) Approx. 6 – 8 Density (25 °C) Approx. 1.04 g/cm3 104
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Boiling point Approx. 102 °C Flash point Nonflammable (when heated to boiling point) Dispersibility in aqueous systems Readily dispersible in all proportions Compatibility Not compatible in solution with anionic products, such as some optical brighteners. Not compatible with chlorine bleaching agents. Precipitated by strong alkalis and complex phosphates. Application Can be applied to cellulosic fibers at a pH of approx. 6 to 9. Action PHMB, the active substance in REPUTEX 20, was optimized especially for finishing textiles. It has a very high binding affinity for cellulosic fiber materials, outstanding wash fastness and an extremely low tendency to migrate. This ensures that the antimicrobial effect of REPUTEX 20 is entirely limited to the treated fiber material. Antimicrobial properties Examples of pathogenic microorganisms whose growth can be effectively controlled with REPUTEX 20 (for example, those that cause skin infections associated with body odor) are listed below. Please note that the minimum inhibitory concentrations (MICs) only show the activity spectrum of REPUTEX 20 and are not the actual application concentrations for textiles. They cannot be used to derive recommendations on the use of the product in the medical or public health sectors. Minimum inhibition concentrations Method: microtitration in nutrient solution (MICs) of REPUTEX 20 APPLICATION Application in the textile industry REPUTEX 20 can be used in the textile industry to produce a durable finish on cellulosic textiles such as cotton, cotton blends with a cellulosic component of over 35 %, rayon, and viscose rayon blended fibers. REPUTEX 20 contains high-molecular-weight PHMB, whose positively charged functional groups bind firmly to negatively charged cellulosic molecules*. During finishing, the cationic biocide binds to the fibers where it produces its effect by inhibiting the growth of odor-causing microorganisms, preventing associated quality defects and ensuring that the finished textiles are permanently fresh and hygienic. * REPUTEX 20 therefore does not bond to protein fibers such as wool and silk or synthetic fibers such as nylon, polyester and polypropylene.
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Fields of application Finishing with REPUTEX 20 is suitable for the following textile applications: • Garments • Towels, bed linen • Cloths • Nonwovens • Upholstery cloth • Technical textiles Application REPUTEX 20 is applied after pretreatment, optical brightening (compatibility test required!), printing or dyeing. Before application of the product on bleached cotton, it should first be ensured that any bleach residues present are quantitatively removed from the fabric. REPUTEX 20 can be applied as a dilute aqueous solution by standard finishing processes such as padding and the exhaust method. Application by spraying is also possible but appropriate precautions must be taken and the equipment used must be enclosed to avoid exposure of personnel to spray mist. Subsequent curing at high temperature of largely cellulosic substrates finished with REPUTEX 20 is unnecessary. pH dependence The affinity of REPUTEX 20 for cellulosic fibers is strongly pH dependent. Optimum bonding between the textile substrate and the active substance is achieved in the 6 – 9 pH range. The pH is set with sodium hydroxide. Sodium hydrogen carbonate and sodium carbonate can also be used. To prevent foam formation, the buffer should not be added too quickly. The pH of REPUTEX 20 liquors should be tested with indicator paper or test strips. Glass pH electrodes do not give reliable measurements in the presence of REPUTEX 20. By way of example, the following graph shows the absorbing power of viscose for REPUTEX 20 at various pH values: Spray application The product should be sprayed on only if the methods described above cannot be employed, e. g. in the case of loose cellulosic fibers or certain nonwovens, e. g. viscose and rayon. The equipment used must be closed and appropriately secured to avoid exposure of personnel to REPUTEX 20 spray mist.
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BIO-POLISHING ENZYME FINOZYME AX is specially designed for application in superior BioFinishing Process and Denim washing of all cellulosic fabrics both woven and knits. CHARACTERISTICS: Appearance Amber coloured clear and viscous liquid. Odour Mild fermentation odour pH 4.5 – 4.9 SPECIAL FEATURES: Clean Finish More effectively removes fuzz and cotton pill balls from fabric/ garment compared to most other acid cellulases. The cutting effect is very obvious. Low Colour Bleeding Exhibits low colour bleeding properties when compared to regular acid cellulases. Softness Significantly softens cellulosic fabric/ garment with reduced strength loss. Flexibility in finish Versatile looks and finish can be achieved by varying the dosage and process parameters. Natural Look Yields permanent softness and luster to the fabric / garment and improves the general look FINOZYME AX is active at a broad range of pH (3.5 to 6.5) and temperature (45 to 65 deg.C).
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1. BioFinishing Process: FINOZYME AX hydrolyses the microfibrils of fabric/ garment thereby effectively removing fuzz/ pill ball and imparts a smoother and polished appearance to surface of fabric/ garment. PARAMETERS OPERATIONAL RANGES Temperature 50 – 60 deg.C PH 4.5 – 5.0; best at 4.8 Liquid ratio
to
goods Fabric 8:1 to 15:1 Garment 6:1 to 10:1
FINOZYME AX Time
0.5% - 3% on weight of garment 30 to 60 minutes
For drum washers try to maintain a low garment liquor ratio for best results. In fabric processing follow the minimum F/L ratio recommended by equipment manufacturer. Unlike many BioFinishing Process Cellulases FINOZYME AX can run at 60 deg.C, thereby offering an approximate of 25% saving in dosage or time. 2) Softening : FINOZYME AX effectively softens fabrics/ garments made up of cellulose and its blends imparting a silky soft permanent finish. FINOZYME AX can be applied on any wet processing step in the garment Finishing Process process. Optional: FINOZYME AX can be applied after preparation/ bleaching, either as a separate process or in conjuction with garment Dyeing Process (more suitable with bifunctional reactive dyes). However, with FINOZYME AX bio-Finishing Process , fabrics/ garments may also be processed after Dyeing Process. 3) Fuzz/ Pill Ball Removal : Using the above process parameters 0.5% -2% owg FINOZYME fuzz balls and fuzziness when run for 15 to 20 minutes.
AX
has been found effective in the removal of
4) Denim Washing : Effective desizing is required for efficient denim washing. PARAMETERS Temperature PH FINOZYME AX Time
OPERATIONAL RANGES 50 – 55°C; best at 52°C 4.5 – 5.0; best at 4.8 6.5 : 1 to 10:1 30 to 60 minutes
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FINOZYME AX can also be used with pumice stones. Removal of loose stains: Follow-up enzyme process with a hot (60 – 70 deg.C) detergent wash. Can be optional if followed up by bleaching.
APPLICATION OF RESIN ON GARMENTS There are two methods of resin applications on the garment 1) Dipping method 2) Spray method 1) DIPPING METHOD Recipe: Fixapret F-ECO 125 g/l to 150 g/l Condensol FM 25 g/l to 32 g/l Perapret F-PEB 60 g/l to 70 g/l Softeners: Silicon softener 15 g/l to 20 g/l (depends on finish) Non-ionic softener 15 g/l to 20 g/l
2) SPRAY METHOD Recipe: Perapret PU-New 80 g/l to 100 g/l ( for spray finish)
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EFFECTS: The company is able to offer garments from all kind of exotic washing techniques like Sand Blasting/ Brushing to most basic stone wash.
BASIC WASHES IN DENIM FABRIC 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.
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DENIM WASHES ARE OF TWO TYPES: 1. Mechanical washes - Stone wash - Microsanding 2. Chemical washes - Denim bleaching - Enzyme wash - Acid wash
MECHANICAL WASHES 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.
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Selection of stone Stone should be selected of the proper hardness, shape, and size for the particular end product. It should be noted that large, hard stones last longer and may be suited for heavy weight fabrics only. Smaller, softer stones would be used for light weight fabrics and more delicate items. Stone wt. /fabric wt. = 0.5 to 3 /1 It depends on the degree of abrasion needed to achieve the desired result. Stones can be reused until they completely disintegrate or washed down the drain.
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PROBLEMS CAUSED BY STONES: - Damage to wash machineries and garment due to stone to machine and machine to stone abrasion - Increase in labor to remove dust from finished garments. - Water pollution during disposal of used liquor. - Back staining and re deposition. BACK STAINING OR RE-DEPOSITION: The dye removed from denim material after the treatment with cellulose or by a conventional washing process may cause "back staining” or "redeposition”. Re-coloration of blue threads and blue coloration of white threads, resulting in less contrast between blue and white threads. REMEDY OF BACK STAINING --- Adding dispersion/suspension agent to wash cycle. - Intermediate replacement of wash liquor. - Using alkaline detergent like sodium per borate with optical brightener as after 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
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STONEWASH EFFECT: In traditional washing process, volcanic rocks or pumice stones are added to the garments during washing as abradant. Due to ring dyeing and heavy abrasion fading is more apparent but less uniform. The degree of colour fading depends on the garment to stone ratio, washing time, size of stones, material to liquor ratio and load of garments. Normally after desizing, stone wash process starts with pumice stone addition in rotary drum type garment washer. Process time varies from 60-120 mins. Stone wash effect is one of the oldest but highly demanded washing effects. Stone wash process gives “used” look or “vintage” on the garments, because of varying degree of abrasion in the area such as waistband, pocket, seam and body. There are many limitations and drawbacks associated with stone washing process, which can be overcome by using new enzyme based washing technology. This technology also helps to conserve water, time, energy and environment.
MICROSANDING There are 3 ways for this technique: • Sandblasting • Machine sanding • Hand sanding or hand brushing
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Used in various ways: - Flat surfaces (tables, ironing boards) - On the dummy (inflatable dummies, sometimes standing, sometimes flat, sometimes 'seated') - Various templates can be used to create a 3D effect. 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.
MECHANICAL ABRASION To give worn out effect, abraded look or used look, some mechanical processes have been developed. These are based on mechanical abrasion by which the indigo can be removed. Some of these processes are sueding, raising, emeresing, peaching and brushing.
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Advantages of these processes: - Control on the abrasion - Different look on the garment can be achieved. - All are dry process. - Economical, ecological and environmental friendly.
Other Mechanical washing
Whiskering Shot gun denim Water jet fading Super stone wash Ice wash Thermo denim Laser technology finish
WHISKERING - Also known as ‘Cat's Whiskers’ - Crease lines around the crotch. - Industrially done with laser, sandblasting, machine sanding, hand sanding and abrasive rods. - Also used for 'knee whiskers' (whiskers on the sides of knees) and 'honeycombs' (crease marks on the back of the knee)
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WATERJET FADING - Hydrojet treatment is used for enhancing the surface finish, texture, durability of denim garment. - Hydroject treatment involves exposing one or both surfaces of the garment through hydrojet nozzles. - The degree of colour 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. - As this process is not involved with any chemical, it is pollution free. LASER TECHNOLOGY - It is a computer controlled process for denim fading. - This technique enables patterns to be created such as lines and/or dots, images, text or even pictures. - It is water free fading of denim. - Being an automatic system, chances of human error are slim. - Also called spray painting in denims. - This technique has relatively high cost. SUPER STONEWASH - Prolonged stonewashing, up to six hours or more.
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ICE WASH - Ice washing in denim fabrics is done to remove more than half the dye during washing
THERMO-DENIM 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 − Applies heavy stonewashing or a cellulose enzyme wash, with or without bleach − Gives an old and worn look
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CHEMICAL WASHES 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.
Process cycle:
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Limitations •
• • • •
Process is difficult to control i.e. difficult to reach the same level of bleaching in repeated runs. When desired level of bleaching reached the time span available to stop the bleaching is very narrow. Due to harshness of chemical, it may cause damage to cellulose resulting in severe strength losses and/or breaks or pinholes at the seam, pocket, etc. Harmful to human health and causes corrosion to stainless steel. Required antichlor treatment. Problem of yellowing is very frequent due to residual chlorine. Chlorinated organic substances occur as abundant products in bleaching, and pass into the effluent where they cause severe environmental pollution.
Advantages •
• •
•
New Laccase based bleaching technique only affects the indigo and natural raw white of weft yarn is retained, giving the woven fabric a darker shade, which is not implicitly achieved with hypochlorite bleaching. The product is so specialised on indigo that it does not attack any other dyes. Laccases open up the door to bleach Lycra containing denim without loosing the strength of the fabric. In case of hypochlorite bleaching Lycra containing product affects adversely by loosing the tear and tensile strength. Finally the process is based on enzyme so no risk of environmental pollution and harmful effluent discharge.
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ENZYME WASH •
•
Cellulase enzymes are natural proteins which are used in denim garment processing to get stone wash look on to the denim garments without using stones or by reducing the use of pumice stone. Cellulase attacks primarily on the surface of the cellulose fibre, leaving the interior of the fibre as it is, by removing the indigo present in the surface layer of fibre.
Cellulase enzyme is classified into two classes: • •
Acid Cellulase: It works best in the pH range of 4.5-5.5 and exhibit optimum activity at 50. Neutral cellulase: It works best at pH 6 however its activity is not adversely affected in the range of ph 6-8 and show maximum activity at 55 C.
Advantage of enzyme washing • • • • • • • • • • • • • • • • •
Soft handle and attractive clean appearance is obtained without severe damage to the surface of yarn. Simple process handling and minimum effluent problem. Better feel to touch and increased gloss or luster. Prevents tendency of pilling after relatively short period of wear. Can be applied on cellulose and its blend. Due to mild condition of treatment process is less corrosive. Fancy colour-flenced surface can be obtained without or a partial use of stone. More reproducible effect can be obtained. It allows more loading of the garment into machines. Environmental friendly treatment. Less damage to seam edges and badges. Wear and tear of equipment is minimum due to absence of stone. Use of softener can be avoided or minimised. Easy handling of floor and severs as messy sludge of stones does not interfere. Due to absence of stone, labour intensive operation of stone removal is not required. Homogenous abrasion of the garments. Puckering effect can also be obtained.
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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. Process cycle
Limitations of acid wash: - Acid washed, indigo dyed denim has a tendency to yellow after wet processing. - The major cause is residual manganese due to incomplete neutralization, washing or rinsing. Remedy: - Manganese is effectively removed during laundering with addition of ethelene-diamine-tetraacetic acid as chelating agent. - Acid washing jeans avoided some of problems of stone wash, but came with added dangers, expenses, and pollution.
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Other chemical washes: • Rinse wash • Cellulase wash • Ozone fading • Snow wash • Salt water denim • Flat finish • Over dye • Sun washing • Super dark stone RINSE WASH - Chemically bleaching jeans so that the color fades away - Breaks down the fibers of jeans and creates white streaks or spots on denim - Gives a unique rugged look, also called snow wash - Earlier involved the use of pumice stone - Presently process involves spraying chemical and removing it immediately - Come in colors like blue, black, green, brown, grey etc.
CELLULASE WASH - This is done to achieve a wash down appearance without the use of stones or with reduced quantities of stones. - Cellulase enzymes 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.
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Factors influencing cellulase performance - pH - Temperature - Time - Dose - Mechanical action OZONE FADING: - By using this technique, the garment can be bleached. - Bleaching of denim garment is done in washing machine with ozone dissolved in water. - Denim garments can also be bleached or faded by using ozone gas in closed chamber. - In the presence of UV light, there is an interaction between the hydrocarbons, oxides of nitrogen and oxygen that causes release of ozone. - Indigo dyestuff tends to fade or turn yellow due to ozone reaction.
The advantages associated with this process are: - Color removal is possible without losing strength. - This method is very simple and environmentally friendly because after ozonized water can easily be deozonized by UV radiation.
laundering,
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
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OVERDYE - Dyeing over the fabric or jeans to add another tone of color - Most often used is a 'yellowy' overdye to create a 'dirty' look - Also can be applied with spray gun or paintbrush for local coloring
SUNWASHING - A very light shade by bleaching and stoning - Looks as if the sun faded the fabric SUPER DARK STONE - Commercial term for an extra dark indigo color - Results from a double-dyeing technique
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SNOW WASH DENIM Denim treated with a variation of acid wash that imparts bright white highlights.
QUICK WASH DENIM • Aims at minimizing wash cycle time • Results in more economical washes and solving many other washing problems faced by launderes during fashion wash cycles • The yarns are ring dyed using indigo giving 25 to 30% less fixed dye to obtain a given shade • During wash cycle,indigo dye can be removed quickly,giving washed look
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Advantages of quick wash denim 1. Streaks develop in garments after washing process due to differences in dye concentration of denim fabrics are avoided using a modified alkali-ph controlled system giving uniformity of shade. 2. Amount of indigo dye required is less thus making it an economical process 3. Time required for washing is 20-30% less than that required for conventional denim. 4. Lesser enzymes and oxidising agent used 5. Environment friendly process 6. Back staining is minimised due to less concentration of of indigo dye in the wash liqour.
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SELECTION OF DENIM FABRIC The right selection of fabric can help minimize the cost of treatment and to solve environment related issues. DIFFERENT COLOUR DEPTH FABRIC: To cut processing time, effluent load, minimum damage to fabric and minimum use of chemical, there are different depth of indigo on denim. For example, in case of ice wash where we remove more than half the dye during washing, one can use lighter shade fabric which will help to cut the process time, chemical consumption, effluent load. It will help garment processor to process garment more economically and with minimum faults. FLAT LOOK DENIM: Different chemicals and processes are used to get flatter look on the denim garments. To meet this requirement special denim fabric has been developed which offers flat look after washing. QUICK WASH DENIM: Quick wash denim fabric is dyed with modified technique of dyeing, so that during wash cycle, indigo dye can be removed quickly, giving washed look at shorter washing cycle. This results in more economical washes i.e. low water consumption, less usage of chemicals, less time and retaining fabric strength. TINTED DENIM: With increase in demand of tinted/ overdyed look on garment, garment processor is using an additional process of tinting/ overdyeing, which is time consuming. It consumes large quantity of water and chemicals. It is also associated with the risk of patches and unevenness on garments. Now the denim fabric is also available in tinted form which saves processors time and risk. GRAINY LOOK DENIM: Different chemicals and processes are used to get grain look on the denim garments. To meet this requirement special denim fabric has been developed which gives grainy look after processing of denim garment. SOFT FEEL DENIM: To meet such requirement, different varieties of denim fabric are available, which are having inherent softness. These fabrics require minimum application of softener at the garment stage.
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NEW DEVELOPMENTS TOWARDS ECONOMICAL AND ECOLOGICAL DENIM PROCESSING USE OF LASER TECHNOLOGY It is a computer controlled process for denim fading. This technique enables patterns to be created such as lines and/or dots, images, text or even pictures. In one version of this concept, a mask is used to give the desired shape that is to be applied on the fabric. The laser projects through a lens system, which expands the beam. This beam is passed through the shaped mask that comprises an aperture of the desired shape and is then deflected by a mirror to strike the textile substrate. The duration of exposure determines the final effect on the fabric. The novelty of this system is that • • • • •
It is water free fading of denim. It is an ecological and economical process. It can create local abrasion and fabric breaks, used look effect, moustache with excellent reproducibility and higher productivity. Being an automatic system, chances of human error are slim. The design is electronically translated on the fabric, thus avoiding the need for photolites of serigraphy cleaning.
The machine is very simple and compact, therefore requires very low maintenance and cleaning, extremely safe and reliable. OZONE FADING: By using this technique, the garment can be bleached. Bleaching of denim garment is done in washing machine with ozone dissolved in water. Denim garments can also be bleached or faded by using ozone gas in closed chamber.The advantages associated with this process are: - Colour removal is possible without losing strength. - This method is very simple and environmentally friendly because after laundering, ozonized water can easily be deozonized by UV radiation. WATERJET FADING: Hydrojet treatment has been developed for patterning and/or enhancing the surface finish, texture, durability, and other characteristics of denim garment. Hydroject treatment generally involves exposing one or both surfaces of the garment through hydrojet nozzles.
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The degree of colour 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. Particularly good results are obtained with blue indigo dyed denim. As this process is not involved with any chemical, it is pollution free. By using water recycling system, the technique can be used as economical and environmental friendly denim processing. Color washout of dye in the striped areas produces a faded effect without blurring, loss of fabric strength or durability, or excessive warp shrinkage.
SPRAY TECHNIQUES This technique is based on spraying the chemicals or pigments to get different effect on the garments. This can be done by using robotic spraying gun or by manual spray and followed by curing of the garment.
-
It a water free process therefore zero effluent discharge. - Less time consuming - Different designs are possible - Easy to use - No adverse effect on fabric strength.
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SINGLE BATH STONE WASHING AND TINTING TECHNIQUE Tinting of denim garment is usually done after the stone wash process. In this, garment has been lightly coloured in order to give the final denim appearance a slight shift. This is not true over dyeing but merely gives the impression of a change in overall colour of the fabric. This process consumes large quantity of water and chemical. To make this process economical and ecologically friendly, some novel colour based enzymes have been introduced in the market. By using this new technique, tinting and stone washing effect can be achieved in a single bath. - Less process time to achieve tinted look. - No extra chemical required therefore making process more economical. - Less water consumption. - Less energy consumption. - Less chance of patches or unevenness Alternate of pumice stone To overcome the shortcoming of pumice stones, synthetic stones have been developed. These are made of abrasive material such as silicate, plastic, rubber or Portland cement. The advantages of using such type of products are: - All major problems associated with the use of volcanic grade pumice stone can be overcome. - Durability of such product is much higher and can be used repeatedly from 50-300 cycle depending upon type of synthetic stone. - Reproducibility of washing is manageable. - As stone discharge of the process is very less, therefore making process is economical and ecological. - Less damage of machine and garments. WASTE WATER SOLUTION As the municipal discharge criteria are restrictive and cost of water high, producers will need to reuse the waste water. Many techniques are readily available for a processor to treat waste water. The basic limitation of a garment processor is the higher installation cost associated with such technique.
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TRIMMING: After washing, broken threads are removed by trimming. In U S Apparel manual trimming is carried out which is mostly done by women.
T R I M M I N G
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BUTTONING Pressing is as important as any other process in garment development. To finish the high quality product that has come through all the stages from cutting, sewing and wet process; no expense has been spared to equip this process by using the latest technology available in the international market. We have machines from Pessani (Italy) for laser guided accurate buttoning process.
B U T T O N I N G
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Button Advice •
Choose your buttons before making buttonholes or loops.
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To determine the buttonhole size, wrap a narrow strip of paper or non-stretch string or twill tape around the button at its greatest vertical circumference (thickness). Hold it securely and slip the button out. Flatten the loop. Add 1/16" to the resulting length. That’s the buttonhole size, but make a test buttonhole to confirm. Button sizes included in pattern notion lists are only suggestions, not absolutes. However there may be design elements that restrict the size choice.
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Button sizes included in the pattern notion lists are the base diameters, not the buttonhole size. Sizes included in our button selections are also the base diameters.
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Square buttons are measured on the diagonal and appear smaller than a round button of the same diameter.
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Thick edge highly domed and ball buttons will require much larger buttonholes.
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Make sure the weight of the button and the weight of the fabric are compatible; or think about how to make them work together. Make sure the fabric texture and button texture are compatible; be careful of delicate surface fabric with irregular finish buttons.
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Single or high-contrast buttons call attention to themselves. Think about the placement. Is that where you want to draw attention?
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If your choice is a square button and you don’t want excess buttonhole stitching exposed, sew the button on diagonally.
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Transparent buttons solve color-matching problems, but they also can disappear or look small or insignificant if they have no outer definition. Look for a translucent style that allows the fabric color to influence the button’s final appearance.
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If an especially large buttonhole is required, or if the fabric is not strong enough for the repeated stress of buttoning/unbuttoning, consider sewing the button on top of the buttonhole and using snap or hook fasteners underneath.
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HOW TO SEW BUTTONS ON TO STAY 1. Cut thread 20-24" long. Use buttonhole twist thread for coats and jackets, good quality hand sewing thread for other garments. Wax the thread in both directions. Thread the needle and knot the ends of the thread together. 2. Start stitching with the knot on the surface where the button will be. The knot will end up under the button. Stitch top to bottom to top, through the button, and back to the bottom. 3. Place a smooth, small "lift" between the button and fabric and between the threads. Try using a T-pin, a round toothpick, a size 1 knitting needle, or a finishing nail. (If you are attaching a shank button, use a smaller lift device.) 4. Make 3 to 4 thread passes through the fabric, button and around the "lift", ending with the needle between the fabric and the button. Remove the "lift". 5. Wrap the needle and thread "figure-8" style, 3 or 4 times around the thread strands to create a shank. 6. End by passing the needle and thread through the cross of the "figure-8" and end with a pass over the final thread loop. 7. The resulting thread shank will be firm and resistant to wear by friction. It will allow flexibility and not pull the fabric.
REPLACEMENT BUTTON TIPS (OR SIZE DOES MATTER!) •
When replacing buttons on a completed garment, knowing the size of the buttonhole is more helpful than having the original button.
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Is the buttonhole flexible? Stiff? Fully clipped?
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If the original button is flat or has a thin edge, you will need to look at a smaller diameter if your replacement choice is higher or has a thick edge.
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Unfortunately, inappropriate size buttons are often on ready-to-wear clothing.
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Never force a button through the buttonhole. Repeated stress or pushing a toolarge button through a tight buttonhole is a primary reason for losing buttons.
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PRESSING Automatic topper presses and auto body presses are used with a combination of manual and auto steam irons from MACPI.
P R E S S I N G
BRAND:
(MACPI)
Electropneumatic pressing machine with manual / automatic control, steamheated shapes, movable and steaming head fitted on an arm having a lever mouvement. Fixed buck. Complete with: - adjustable pressing pressure and sponging height - electronic safety head guard device - 555.04 locking of the plate: unstable - 555.05 locking of the plate: stable Feeding: 1+N~50Hz 230 V
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FINISHING US Apparel has one of the most modern garment wet processing facility in the country. The electric mix of Italian, Spanish and Far Eastern equipment allows U S Apparel to provide its customers an almost infinite range of garment washing/dyeing facility.
F I N I S H I N G
Computerized control over wash process allows U S Apparel to give consistent wash quality in long running or repetitive production requirements. Wet process department performance is further cemented with the support of extensive computerized database and a well equipped laboratory. The company is able to offer garments from all kinds of exotic washing techniques like Sand Blasting/Brushing to most basic stone wash.
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PACKING:
P A C K I N G
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GLOSIERY OF DENIM Abrasion The process of making garments look worn and aged by scraping or rubbing the surface of the fabric causing abrasion.
Acid Wash The finish that gives indigo jeans sharp contrasts by soaking pumice stones in chlorine and letting the stones create the contrast.
Bartak Stitching that reinforces places on jeans such as flies and pocket openings. Bleach A chemical used to make denim fade. Carding
The process in which raw cotton is separated and cleaned to make a sliver.
Cotton After blooming, this plant turns from white to purple, providing the well-known textile that withstands high temperatures, accepts dyes well, and increases in strength when wet. The quality of cotton is determined by the length of fibres; the longer the fibres, the higher the quality.
Crocking A term used to describe how dye rubs off fabric on skin or other fabric. Crosshatch Mixing uneven yarns in both the weft and warped directions to create a unique type of denim that shows a square grid-like pattern in the weave.
Defoliant A chemical that causes plants' leaves to drop off earlier, used to speed up the harvesting process of cotton.
Denim The word denim is believed to be a derivative of the French term, serge de Nîmes, a rugged cotton twill textile, in which the weft passes under two or more warp fibers, producing the familiar diagonal ribbing identifiable on the reverse of the fabric distinguishing denim from cotton duck.
Dips What fabric or yarn are called when dipped in dye. Double Needle A common seam on jeans where two stitches run parallel to each other for reinforcement.
Dual Ring Spun The process in which both the warp and weft threads are made of ring-spun yarn. It creates a much softer and textured hand than regular (single) ring-spun denim.
Enzymes Proteins that speed up chemical processes. They are used in textile processing, mainly in the finishing of fabrics and garments. Enzyme Wash A more environmentally sound way to create a stone wash, organic proteins are used to eat away at the indigo.
Finishing The overall processes performed on a garment giving it its unique look. Five Pocket Jeans Most frequent design for denim: two back pockets, two front pockets and a coin pocket inside the right front pocket.
Ginning The process in which seeds are removed from picked cotton. 139
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Hand The term used to describe how denim feels. Indigo A blue dye obtained from indigo plants. The chemical structure was synthetically produced in 1987. Indigo's inherent features are good colorfastness to water and light and a continual fading. This allows the blue color in jeans to always look irregular and individual. Jean Possibly derived from the French work "genes", it was first used to describe the type of pant worn by Genoan sailors.
Laundry A facility that takes unwashed jeans and processes them; i.e. stone wash, sandblasting, finishing, etc. It is essential in creating commercial denim and has become as important as fabric development.
Laser technology, initially used by the military, has developed dramatically in the last few years as a textile treatment with laser finishes. Used with automated Tonello machines, lasers can be directed vertically or horizontally and used to create both specific detailing or a textured all-over effect. The frequency of the laser is set to erode the indigo surface in order to either alter the color or burn through the cloth. Laser treatments are used exclusively in the upper end of the denim market and are considered a more environmentally acceptable process than the traditional methods of finishing.
Left-Hand Twill A weave in which the grain lines run from the top left-hand corner of the fabric towards the bottom right. Usually in piece-dyed fabrics, left-hand twill fabrics are woven from single piled yarns in the warp. They often have a softer hand feel to them after washing.
Loop Dyed One of three major industrial methods of dyeing indigo yarn. Open-End Spinning A spinning process in which individual fibers are fed into a high-speed rotor shaped like a cup where they begin to accumulate. The yarns produced using this method are not as strong as the ring-spun yarns of the same size. Overdye A dying process in which additional color is applied to create a different shade or cast on the garment.
Oxidation In denim manufacturing, when indigo yarn comes out of the dip and joins oxygen, penetrating the fibre. Padazoic A dye used in the late 1960's - early 1970's in place of indigo, which was in short supply and high demand. Pigment Dyes Dye that lack the ability to grab onto the fibers and must be held to the fabric with resins. Pima Cotton Originally grown in the 1900's in Peru, Pima Cotton is known for its long fibres, making it a very high quality, luxurious cotton. Pima Cotton was brought to America and got its name from the Pima Indians, who harvested this particular type of cotton.
Polyurethane Provides a chemical resistance in the washing and dyeing process in order to achieve the desired denim wash/ color. It is the basis of a novel type of elastomeric fiber known generically as spandex. It is a man-made fiber (segmented polyurethane) able to stretch at least 100% and snap back like natural rubber.
Pumice Stone Lightweight and strong, this stone is used in the process of stone-washing apparel. Ring Dyeing Describes a quality unique to indigo dye in which only the outer ring of the fibers in the yarn is dyed while the inner core remains white.
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Ring Spinning The process that creates unique surface characteristics in a garment by feeding individual fibers into the end of the yarn while in its twisting zone producing an irregular authentic vintage look. Ring-spun yarns add strength, softness and character to jeans.
River Washing The process that creates a naturally aged look by combining pumice stones and cellulose enzymes. The washer is first loaded with stones and fabric. The second stage introduces the enzymes and tumbled together to give denim a vintage, worn hand.
Rivet A metal accessory that is used for reinforcement of stress points as well as nonfunctional ornamentation. Sanding Process that makes the surface of a garment soft by rubbing aggressively with paper containing small loose grains of worn rock.
Sanforization: A process which shrinks and stabilizes cloth before it is cut. Sanforization was invented by Sanford L. Cluett and patented in 1928. Most denim companies followed suit, apart from Levi who still produced “shrink to fit” denim for three decades following.
Sea Island Cotton Known for its silky feel and lustre, one of the best cotton fibres. Selvage The edge of a fabric that is woven so that it will not fray or ravel. Old 28 to 30 inch shuttle looms produce denim where selvages are closed, whereas on the larger modern weaving machines the weft yarn is cut on every pick, creating what is called a fringe selvage.
Slasher Dyeing One of the three main methods of dyeing indigo yarn Spinning A process used to create yarn or thread where short fibres are twisted together. These yarns will be used to weave into cloth or used in sewing. Longer fibres like silk are not spun. Spraying & Staining: Spraying color can be added at various stages in the finishing cycle, either by hand or by automated robot. The effect adds to the aged look of a garment by introducting stained areas, color contrast or blotched tints. These appear more “natural” following laundry treatment. Overdyeing and tinting is carried out in giant washing machines, where a dirty or stained effect is achieved via the use of a pigment dye. The more subtle and sophistocated effects are hand-applied to individual areas.
Stone Washing Process that physically removes color and adds contrast using pumice stones. The longer the denim and stones are rotated the lighter the color becomes and more contrast occurs. The denim is then rinsed, softened, and tumble-dried.
Sulphur Bottoms: Many manufacturers apply a sulphur dye before the customary indigo dye. This is known as Sulphur Bottom Dyeing. It can be used to create a grey or yellow “vintage” cast. Warp: Yarn that runs parallel to selvedge. In denim, it’s dyed indigo.
Weft The un-dyed crosswise filling yarns used in denim weave. Weight: Denim is traditionally graded by its weight per yard of fabric at a 29-inch width. Early jeans were nine-ounce Levi’s, increasing to 10-ounce in 1927. Lee Cowboy Pants were introduced in the much heavier 13-ounce weight, and most modern jeans are now 14 ounces.
Whiskering Term used to describe a denim that has a fading of the ridges in creases in the crotch area and back of the knees giving the appearance of aged denim. 141
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