THE A-Z OF DENIM

The A-Z Of Denim
A complete A-Z glossary of denim terms from finishes, detail and weaves to mills, branding and history ...
A
ABRASION
Process of making garments look worn and aged by scraping or rubbing the surface of the fabric causing abrasion. Pumice stones are most frequently used by industrial laundries.
ACID WASH
(Marble/ Moon Wash/ Snow Wash)- This finish gives indigo jeans sharp contrasts. The process is achieved by soaking pumice stones in chlorine and letting these stones create contrast. The process was created in Italy and patented in 1986.
AGED
A kind of wet processing that gives the garment an artificial worn look and a softer feel through prolonged abrasion.
ANTI-TWIST
A step in the finishing process, before sanforization, that corrects denim’s natural tendency to twist in the direction of the diagonal twill weave. Also known as skewing.
AMOSKEAG
A New Hampshire factory town which was the first major source of denim in the US. The Amoskeag Manufacturing Company opened in 1838 and by 1900 claimed to be the world’s biggest textile producer; it later declined due to industrial unrest and competition from southern mills. On Christmas Eve, 1935 the Amoskeag Manufacturing Company closed abruptly closed its doors and filed for bankruptcy and a flood soon after crushed any hope of reopening. Denim from Amoskeag was prolific and hugely influential in the success of the fabric, being used exclusively for Levi’s® 501 until 1915.
ARCUATE
Distinctive double stitching used on the back pocket of the very first Levi’s® jeans, now acknowledged as the world’s oldest clothing trademark. The shape became synonymous with Levi’s® jeans by 1900, although it’s conceivable that other early work wear might have used the device before them. LS&Co. trademarked the stitching in 1943.
ATARIA
Japanese term describing the selective fading of the ridges of creases. The most common areas for ‘Atari’ are along side seams, on the front and back of the knees, the upper thigh, along the hem, on belt loops and along pocket seams.
AUTHENTIC
A jeanswear term used to describe both original jeans qualities and stone and enzyme wash optics. It became a marketing buzzword in the early 90’s, when the quest for original denim swept the European market. Among the characteristics of authentic jeans are traditional fabric weaves and styling details.
B
BACK CINCH
Also known as martingale, the back cinch with a back buckle was used to tighten the waist on jeans before widespread use of belts; hence the term ‘buckle back’. Most jeans makers abandoned them by 1942; with renewed interest in vintage-style looks, cinch backs have returned on modern jeans including Evisu, Atelier La Durance and Levi’s®.
BACK POCKET FLASHER
A paper or cardboard flap attached to the right back pocket of jeans and used to communicate differences in denims, washes, styles and size.
BARTACK
A sewing procedure that reinforces stress points on jeans- usually found near zippers and pocket openings.
BELL BOTTOMS
A jeans style born in the late ‘60s and popularized in the 70’s by brands such as Landlubber Jeans. This style was tight at the waist and thighs and the trousers flare out from the knee down. The name ‘bell bottoms’ presumably originates in the fact that the legs of these jeans take on the shape of a bell or trumpet when viewed from the side.
BELT LOOPS
Belt loops were first added to the waistband of the Levi’s 501 jean in 1922 to allow a belt to be worn without slipping. Both suspender buttons and the cinch back still remained on these first styles. A classic pair of jeans usually has 5 belt loops – 2 in front above the front pockets, 2 more at each side and one at the back.
BIG EA
term used to describe Levi’s® clothing made before 1971, at which time the all uppercase logo on the red tab was redesigned with a lower case ‘e’. Levi’s® jeans with a big ‘E’ are considered vintage and more valuable than later little e’s.
BLACK-BLACK DENIIM
Denim where the warp yarn is black instead of blue and which is also dyed black after weaving. this makes the jeans truly black rather than gray.
BLEACH
A chemical used to make denim fade. Liquid bleach is usually an aqueous solution of sodium hypochlorite, and dry powdered bleaches contain chloride of lime (calcium hypochlorite).
BOOT LEG
A popular jeans style cut wide enough in the leg to accommodate a pair of cowboy boots underneath.
BROKEN TWILL
A denim weave first used by Wrangler in 1964 as style 13MWZ. The diagonal weave of the twill is intentionally reversed at every two warp ends to form a random design. This type of weave reduces the natural torque characteristic of regular twill weaves, and has the effect of eliminating leg twist.]
BUDDY LEE
This cherub-cheeked ceramic doll, clad in Lee overalls, was introduced in 1920 as H.D.Lee’s first promotion. As popularity grew, the doll gained a larger wardrobe including cowboy duds and railroad uniforms. Production stopped in 1962 and today the dolls are favourites with collectors.
BULL DENIM
A heavyweight denim weave (14oz. plus) with a typical 3x1 twill construction. An ecru fabric, bull denim is later printed or garment dyed.
BUTTON
The traditional jeans button is made of two parts: a short ‘nail’ fixed on the fabric and the visible part pressed on the nail. It is typically made of a metal alloy- copper, brass or aluminium- and bears the brand’s logo, symbol or initial on its face. Some jeans buttons, composed of three parts, have a moveable head for better flexibility in fastening.
C
CASTE
A term that describes shading. Depending on the method and type of dye used, indigo denim can have a black, brown, gray, green, red, or yellow caste to it.
CELLULOSE ENZYME WASH
Enzymes which are like yeast , are used to physically eat away the cellulose in cotton. Since the colour in denim fabric is actually on the outside of the yard, when the denim is washed in a cellulose enzyme bath the indigo is removed along with the fiber. When the desired colour has been achieved, either changing the alkalinity of the bath or heating the water stops the enzymes from reacting. A rinsing and softening cycle follows. This process is more environmentally friendly than stone washing because strip-mined pumice stones are not used.
CHAIN STITCHING
A series of looped stitches that form a chain-like pattern. Chainstitching pulls the denim at slightly different tensions on either side, causing the distinctive ‘roping’ that really shows the beauty of worn indigo-dyed denim.
COIN POCKET
The fifth pocket, also called watch pocket. Strictly functional, it sits inside the right front pocket and justifies the term five-pocket jeans. Also known as match or watch pocket.
CONE MILLS
Cone Mills started producing denim in 1895 in Greensboro, North Carolina. The company started supplying denim for Levi’s® jeans in 1910, becoming the exclusive supplier for the 501 in 1922. Cone is still one of the world’s biggest denim manufacturers.
CROSSHATCH
A unique type of denim that shows a square grid-like pattern in the weave. It is created by mixing uneven yarns in both the weft and warp directions.
D
DENIM
A sturdy cotton twill fabric characterised by a 3x1 warp-faced weave in which the weft passes under two or more warp fibres producing the familiar diagonal ribbing, identifiable on the reverse of the reverse of the fabric. Traditionally denim is made with indigo-dyed yarn for the warp and natural yarn for the weft.Originally called Serge De Nimes for the French city where it was produced, denim is now manufactured in specialized mills around the world.Denim is an indigo-dyed cotton twill fabric, woven with a dyed warp yarn and a natural fill yarn. The term derives from Serge De Nimes; but denim and Serge De Nimes are in fact different fabrics.
DESIZING
An amylase enzyme rinse (desize) used to soften denim. A type of size such as cornstarch is added to the warp yarns prior to weaving in a process called slashing, which adds stiffness to the yarns. During the desizing step, the amylase enzyme attacks the starch and removes it from the fabric. Although this process reduces colour slightly, it is primarily used to give a softness and drapability to denim.
DIPS
Used to describe fabric or yarn when they are immersed in dye. Indigo yarns are usually dipped in an indigo bath six times.
DUAL RING-SPUN
Also called “ring X ring”. Signifies a denim weave in which both the warp and the weft threads are made of ring-spun yarn. Creates a much softer and textured hand than both open-end and regular (single) ring-spun denim. Due to the additional labour required to produce dual ring-spun denim, it is usually only used by higher end, premium denim labels.
E
ENZYMES
Enzymes, which are proteins present in all living cells, speed up chemical processes that would run very slowly if at all. They are non-toxic and readily broken down. Enzymes are used in textile processing, mainly in the finishing of fabrics and garments.
ENZYME WASH
Considered a more efficient and environmentally sound way to stone wash jeans. Rather than using pumice stones, organic enzymes (proteins) are used that eat away at the indigo. Jeans finished using enzymes tend to be stronger than those broken down by traditional stone washing, as the fabric is not subjected to the same level of abuse.
F
FINISHING
The techniques or processes performed on a garment, which give it it’s unique look.
FIVE POCKET JEANS
One of the most common styles of jeans; they have two back pockets, two front pockets and a coin pocket inside the right front pocket.
G
GARMENT DYE
A dyeing process performed on finished garments, as opposed to a yarn dye, which takes place prior to the weaving of yarn. If you see pocket linings or labels that look the same colour as the self-fabric, the garment was likely garment dyed.
H
HAND
A description of the way a fabric feels. A subjective judgement of the feel or handle of a fabric used to help decide if a fabric is suitable for a specific end use. The hand can be described as crisp, soft, drapable, smooth, springy, stiff, cool, warm, rough, hard, limp, soapy etc. Finishing and garment wash will affect the final hand of a fabric.
HANK DYEING
This is a very special dyeing process that very few people use. The yarns are loosely arranged in skeins or hanks. These are then hung over a rung and immersed in a dye bath being dipped in and out and left to oxidize in the air between each dip giving the yarns a natural irregularity of patina and caste. In this method, the colour penetration is the best and the yarns retain a softer, loftier feel.
I
INDIGO
The dye used for denim, initially taken from the indigofera tinctoria plant. It was synthesized 14 years after it’s chemical structure was identified by Adolf Bayer in 1897. Indigo’s inherent features are good colour fastness to water and light, a continual fading and it’s inability to penetrate fibers completely. This allows the blue colour in jeans made dyed with indigo to always look irregular and individual. Pre-1920’s jeans were generally dyed with natural indigo and were- as far as one can tell by comparing vintage examples- paler in colour, with a green cast. Later jeans were a darker blue, particularly used in combination with sulphur dyes. The majority of indigo used today is synthetically made. Natural indigo has a slightly red cast.
IRO-OCHI
Japanese term referring to the fading of indigo dye in denim. The term specifically relates to fading in exposed areas and not across the entire garment.
J
JEAN
The term is possibly derived from the French word ‘genes’. It was originally used to describe the type of pants worn by sailors from Genoa. While the historical definition implied that all jeans were made of denim, the term jeans today can sometimes refer to a garment that has five pockets and be made from fabrics such as corduroy, twill or bull denim.
K
KHAKI
Chinos, combat pants, military styles in khaki and olive- these became a popular replacement for jeans amongst the youth of the 90’s.
L
LAUNDRY
In the ‘Denim Industry’, a Laundry is a manufacturing company that takes unwashed jeans and processes them. This processing includes washing, stone washing, sandblasting, garment dyeing , finishing, use of ‘Tonello’ machine with abrasive bristles, applying enzymes to simulate a ‘whisker’ effect and sandpapering by hand. Laundries today are critical in making jeans look commercial and wash development has become as important as fabric development in the denim industry. The best Laundries and wash developments come from the U.S, Japan and Italy.
LEFT-HAND TWILL
Also known as an ‘S Twill’, this is 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 plied yarns in the warp. The denim brand Lee has always used left-hand twill denim as it’s basic denim. Left-hand twills will often have a softer hand feel to them after washing than right hand twills.
LEG TWIST
Many vintage jeans suffer from leg-twist. This is simply a natural adjustment of the fabric, which tends to follow the direction of the weave. Stefano Aldighieri, Director of Fabric & Finishing at LS&Co. explains it thus: “Levi’s® denim were mostly right hand twills; the twill line rises to the right. During the weaving process you basically ‘force’ the fabric to be straight, perpendicular to the selvage, but at the same time you give it this direction in the construction. You lay and cut the fabric; in the early days LS&Co. patterns were cut straight along the selvage. When you wash the garments, the fabric will try to follow the direction of the weave and will pull in that direction... hence the twisted legs, the result of the movement of fabric. Because Lee started to use left hand weave denims, their legs would twist the other way.” Leg twist was eliminated in the 1970s by skewing (which contorts denim to its after-wash shape)- and later revived with Levi’s® Red and Engineered jeans.
LOOP DYED
One of the three major industrial methods of dyeing indigo yarns. In the loop dyeing process, the yarn is dyed in a single bath instead of several. The desired depth of colour is attained by passing the yarn through the vat several times. Subsequently as part of the same process, the yarn is sized.
M
MERCERIZATION
An industrial process used on yarn or fabrics to increase it’s lustre and dye affinity. For fabrics used in the denim industry, mercerization can be used for keeping dye on the surface of the yarns or fabrics and to prevent dyes from fully penetrating the fibres.
MICROSANDING
In this fabric treatment process, a series of cylindrical rolls in a horizontal arrangement, either wrapped with an abrasive paper or chemically coated with an abrasive , are used to create a soft, sueded hand. The denim is pulled over the face of the sand rollers creating a raised surface finishinig. Some colour reduction is experienced.
N
NATURAL DYE
Up to to the middle of the 19th century there were only natural dyes and most of these these were vegetable origin. Natural indigo being one of the more important dyes. Natural dyes usually have no affinity for textile fibres until the fibres are treated with aluminum, iron, or tin compounds to receive the dye (mordanting). This is a problematic process and the dyes in any case have poor fastness to sun or abrasion.
NATURAL FIBRES
Any hairlike raw material directly obtainable from an vegetable, animal, or mineral source that can be converted, after spinning, into yarns and then into woven cloth.
O
OPEN END DENIM
Open End or OE spinning was introduced in the 1970s, reducing costs by omitting several elements of the traditional spinning process. The cotton fibres are ‘mock twisted’ by blowing them together. Open End denim is bulkier, coarser and darker, because it absorbs more dye, and wears less well than Ring Spun denim. Although cheaper to produce it has been used on many designer jeans, including Calvin Klein and Tommy Hilfiger.
OVERDYE
A fabric dyeing process in which additional colour is applied to the fabric or garment to create a different shade or cast. ‘Dirty Denim’ is often created by applying a yellow overdye to denim. By localising the application of the tint, you can create specific areas that look dirtier than the surrounding areas.
OXIDATION
Occurs when oxygen and another substance chemically join. This occurs when indigo yarn comes out of the bath between dips.
P
PIGMENT DYES
Dyes that do not have an affinity for fibre and must therefore be held to the fabric with resins. They are available in almost any colour and are used extensively in the denim industry by fabric dyers who want to create fabrics that fade more easily.
PLY
All yarns are single ply unless twisted with another yarn. Plied yarns are used to make yarns stronger. In the denim industry, it has become important to ply yarns stronger. In the denim industry, it has become important to ply yarns in piece dyed fabrics that are intended to endure a long stone wash cycle. The method of twisting and length of each yarn is a major determinant in the ultimate look and feel of the finished fabric.
POLYCORE DENIM
Often found in replica jeans, offers the best mix of strength (polyester core) and vintage aesthetic (cotton top thread layer).
PUMICE STONES
Volcanic stone used for stone washing garments. Pumice is popular because of it’s strength and light weight. Before the use of pumice, rocks, plastic, shoes and just about every other material was used to wear down and soften denim during the laundry process.
Q
QUALITY CONTROL
Each pair oj jeans is subjected to a series of quality checks. The first random samples are examined during pre-sewing. Then after the pieces are assembled, every single pair of jeans is individually examined, and again after washing.
R
RIGHT-HAND TWILL
Most denim is right-hand twill, a weave which produces a diagonal, or twill, line which rises from left to right. This was standard practice in weaving; single yarn warps were woven right-hand, double yarn warps were woven left hand. Most Levi’s® jeans are right-hand twill whereas most Lee jeans are left-hand twill.
RING DYEING
Describes a characteristic unique to indigo dye in which only the outer ring of the fibres in the yarn is dyed while the inner core remains white.
RING-SPUN DENIM
Ring spun yarns were traditionally used in denim up until the late 1970s, but were later supplanted by cheaper Open End yarns. This is a spinning process in which the individual fibers are fed onto the end of the yarn while it is in the ‘twisting’ stage. The process consists of a ring, a ring traveller and a bobbin that rotates at high speed. The ring-spun yarn produced by this method creates unique surface characteristics in the fabric, including unevenness, which gives jeans an irregular authentic vintage look. Ring-spun yarns add strength, softness and character to denim fabric.
RING-RING DENIM
Ring/Ring, or double ring-spun denim uses ring-spun yarn for both warp and weft. This is the traditional way to produce denim. It’s possible to combine a ring-spun warp fabric with an Open End weft, to get much of the strength and look of the traditional ring/ring denim at lower cost.
RIVER WASHING
A washing process using a combination of pumice stones and cellulose enzymes to give denim a vintage, worn hand. The washer is loaded only with stones and fabric for the first cycle. Enzymes are introduced for the second stage in combination with the stones and they are tumbled until a naturally aged look is produced.
RIVET
A metal accessory that is used for reinforcement of stress points as well as for non-functional ornamentation.
ROPE DYEING
Considered the best possible method to dye indigo yarns. The threads of denim yarn are twisted into a rope, which is then fed through sequence of being dipped into a bath of indigo dye, followed by exposure to air, multiple times. The frequency determines the ultimate shade of blue.
S
SANDBLASTING
A laundry process performed before washing in which jeans are shot with guns of sand in order to abrade them and cause a worn appearance. While originally done by hand this process is now automated at most large laundry houses.
SANDING/EMERSING
A fabric finishing process where fabrics are sanded with real sandpaper to make the surface soft without hair. It can be performed before or after dying.
SANFORIZATION
A pre-shrinking fabric process that limits residual fabric shrinkage to under 1%. The process includes the stretching and manipulation of the denim cloth before it is washed. Raw, un-sanforized jeans will shrink 7-10% after the first wash, and continue to shrink slightly up to the third wash. Developed in the late 1920s by the Sanforize Co. and patented in 1928, the process was reportedly first used by Erwin Mills in 1936 to make denim for overalls marketed under JC Penney’s Big Mac label. Lee jeans were made from Sanforized fabric soon afterwards, Lady Levi’s® introduced around 1935 were also Sanforized although most other Levi’s® jeans remained shrink-to-fit for another three decades.
SELVAGE
Also referred to as ‘Redline’ or ‘Aka-Mimi’. Originally called ‘self-edge’, the selvage is the narrow tightly woven band on either edge of the denim fabric, parallel to the warp. A selvage end prevents the edge of the denim from unravelling. Old 28 to 30 inch shuttle looms produce denim where selvages are closed, whereas on larger modern weaving machines, the weft yarn is cut on every pick, creating what is called a ‘fringe’ selvage. Coloured thread was used by Cone Mills to identify the particular fabric used by it’s major manufacturers. Vintage Levi’s® jeans began with an all white strip and later had a single red strip along both selvages, Lee’s had a blue or green strip along one end and Wrangler’s was yellow.
SHADE BATCHING
The process of selecting batches of fabric into homogeneous shade lots to obtain consistent colour continuity in garment making.
SHADE BLANKET
Fabric is cut from each roll of fabric and sewn together with roll numbers on the back of each roll. This is an important tool in cutting apparel made from denim to ensure that garments from the same shade group are cut.
SHRINKAGE
Traditionally before denim is woven, the threads it’s made of are treated with wax or resin to stiffen them and make them easier to weave (although with most repro denim starch is used instead.) When dry/raw/unwashed denim is washed for the first time the fibres constrict and the denim shrinks. Raw denim can be sanforized (treated with a sanforizing process that lessens shrinkage) but all raw denim will shrink to some degree upon immersion in water, up until it’s third wash.
SHED
During the weaving process, this is the opening formed by raising and lowering the warp yarns on a loom. The shed opening is what the weft yarns are passed through to complete the weaving interlace.
SHUTTLE
The device that carries the weft yarn across the loom in vintage shuttle looms. Selvage denim can only be woven using a shuttle loom.
SILHOUETTE
Refers to the shape of a garment (i’e bootleg, relaxed, low rise, slim, carpenter, etc...)
SIZING
Starch, gelatine glue or wax that is added to fabrics in the finishing stage to improve touch or weight and to help fabric laying in the cutting phase. Denim fabrics, for example can have almost one ounce of sizing.
SKEWING
Refers to the occurrence of twisting that happens when the fabric shrinks more perpendicular to the twill line than along the twill line. Without compensating for this occurrence, the twill line will cause the right angles that the fabric is woven in to torque approximately 5° after washing. To compensate for this, denim is skewed about 5° in the same direction as the twill line tom prevent the side seam from twisting to the front of the jean. You will often find authentic vintage jeans with one or both of the side seams twisted towards the front of the jean.
SLASHER DYEING
One of three main methods of dyeing indigo yarn.
SLIVER
In the yarn manufacturing process, a sliver refers to the loose, soft, untwisted rope of cotton fibers that is produced using the carding machine.
SLUB
Refers to thick or heavy places in the yarn. Slubs and other inconsistencies are common in denim produced on vintage shuttle looms. Modern yarn spinning technology is able to engineer these vintage looking textures into yarn in a predefined manner.
STONEWASHING
A process that physically removes colour and adds contrast. A 20 yard roll of fabric, generally 62 inches in width, is put into a 250-pound washing machine along with pumice stones. The fabric and stones are rotated together for a set period of time. The washing time dictates the final colour of the fabric- the longer the denim and stones are rotated the lighter the colour becomes and more contrast is achieved. The denim is then rinsed, softened and tumble dried. Both Marithe & Francois Girbau from France and the Japanese ‘Edwin’ claim to have pioneered this finishing technique.
SULPHER BOTTOM
Many manufacturers apply a sulphur dye before the customary indigo dye; this is known as Sulpher Bottom dyeing. This can be used to create a grey or yellow ‘vintage’ cast.
SUSPENDER BUTTONS
Attached to the waist bands of jeans to attach suspenders and braces these became less common from the late 30s when suspender buttons were removed to make getting dressed easier for the modern belt-wearing man. However many retailers stocked and fitted ‘Press On’ buttons for customers who preferred suspenders to a belt.
T
TATE-OCHI
Japanese term referring to occurrences of ‘Iro-ochi’ forming in vertical lines in vintage denim. As the thread width is not uniform in vintage denim, the colour fades the most where the thread is the thickest. This creates a white or severely faded thread of several centimetres along a single vertical indigo thread.
TOP STITCH
A commonly used straight simple stitch.
TWILL
The diagonal lines formed by the weave.
U
UNWASHED
Exactly what the word says- jeans that have been left unwashed, a characteristic that goes back to pre-sanforized days, when manufacturers sold their garments dark, stiff and not pre-shrunk. Some brands offer jeans this way for purists who want to break in their own jeans on their own bodies to recapture the original magic of denim’s good old days.
USED WASH
Term referring to a type of placed abrasive effect or sandblasting, made individually on each garment in special areas like the knees, pockets, thighs bottom etc...
V
VENETO
A Northern Italian region considered the cradle for some of the most successful names of the International jeans industry. Denim brands such as Diesel, Replay, Gas and Seal Kay were all born and raised here as were famous laundries such as Martelli.
VINTAGE
From the past; old or secondhand. Vintage jeans can either be previously worn or never worn and sorted in their original state
W
WAIST OVERALLS
The original term for what we know as jeans- Levi’s® continued to use this term up until the 1960s to distinguish their jeans from bib overalls.
WARP
This is the lengthways vertical yarns woven into the weft yarn. They usually have more twist and are stronger than weft yarns. In denim it runs parallel to the selvage and is dyed indigo.
WEAVE
The combination of warp and weft yarns woven into the weft yarns to produce different weave designs. The warp face designs used in the denim are called out by the number of weft yarns that the warp ends pass over followed by the number of weft yarns they pass under. Some of the most common denim weaves are 3x1 and 2x1 can be made in left or right-hand twill directions. 3x1 right-hand twill is the most common design.
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 Levi’s® were 9oz denim, increasing to 10oz in 1927; Lee 101 Cowboy Pants were introduced in the much heavier 13oz weight; most modern jeans are around 14oz.
WHISKERING
A fading of the ridges increases in the crotch area and back of the knees, which gives the appearance of aged denim. It can also be inverse- dark creased in faded denim.
X
XX
The name used originally to reference a particular model of Levi’s® jeans built prior to 1890. The XX has been present ever since and is used as both a lot or ordering number and to signify Levi’s® highest quality denim, ‘501 XX’, woven by Cone Denim.
Y
YARN DYE
Refers to fabric in which the individual yarns are dyed prior to weaving- denim is a yarn dyed fabric.
YOKE
V-shaped section at the back of jeans, also known as a ‘riser’, which gives curve to the seat. The deeper the V of the yoke, the greater the curve. Cowboy jeans often feature a deep yoke whereas workwear or dungaree jeans might have a shallower yoke- or no yoke at all.
Z
ZIP
The alternative to the button fly, first used for jeans by H.D. Lee in 1926. Wrangler was the first to do a centre zip fly for women in its Jeanie line, which debuted in 1950. The innovation was considered hazardous at first, but eventually became a huge success.
ZIPPER
A popular jeans closure. Also sometimes used as a design detail on back pockets or on tapered pants legs. The zipper was invented in 1893 by American W. Litcomb Judson as a system of small hooks and eyelets; it was improved by Swedish Gideon Sundback in 1913, when it became a system of small metallic teeth intertwined with a movable clasp.

Sulphur Black Dyeing

                         Sulphur Black Dyeing in cotton and polyester
                 cotton blend quality in different Dyeing machine

Sulphur dyeing is used for dyeing of cotton and in market it is available in powder and liquid form also. In exhaust dyeing maximum powder form is used in dyeing of cotton material. In sulphur black dye main advantages it can cover immature cotton available in fabric portion and get lot of fashion shade. Even in Fabric
Dyeing general fashion is there if shade wise any major problem is there convert it sulphur black shade. Here in this article we are going to show the sulphur dye used in different machinery.

Drumming machine:

For garment micro garment quality was used (50% polyester and 50% cotton blend quality) one trail was observed in 50 kg lot.

Quality:-micro garment quality (50% polyester and 50% cotton blend quality)
Quantity:-50 kg M; L:-1/15
M/c used:-Drumming m/c Order:-For local quality.

Process used:

I) Desizing agent (Enzyme) =200 gram Lubricant =500 gram OT =200 gram (Run at 55 degree Celsius, 20 minute holding time.)--------Washing---------

II) Lubricant = 500 gram Sulphur Black =4.500 kg Sodium Sulphide=4.500 kg Common Salt =10 kg Soda ash =700 gram (65-70 degree Celsius, holding time 30 minute)----Washing----

III) Hydrogen peroxide=700 gram Acetic Acid=400 gram (10 minute holding, cold) IV) Bio-polishing:- Bio-SL (Enzyme) =400 gram Lubricant=500 gram Acetic Acid=800 gram (Holding time 30 minute, at 50 degree Celsius)----Washing---washing----unloading for finishing section.

Note: Acetic Acid quantity was taken more because water PH is alkaline coming range 8.0-8.5. From above it was observed three processes was involved .

Desize----sulphur dyeing---oxidation---bio-polishing—washing---washing .

The above lot within 2 hours was taken out. Result was satisfactory for local quality within short time getting result.

Continuous Dyeing machine:

For Cotton Twill quality (Drill quality) Order:-Export Quality.

I) Sulphur Black dye=95 gpl Crypto-anionic wetting agent=2 gpl Antimigrating agent=10 gpl Padding----drying-----Chemical padding

II) Chemical Padding:- Soda ash=20 gpl Sodium Sulphide=95 gpl Padding—steaming—cold wash-oxidation

III) Oxidation:- Potassium dichromate=5 gpl Acetic acid=2 gpl (50-55 Degree Celsius)

IV) Soaping;- Soap=0.5 gpl Soda ash=0.5 gpl (85-90 Degree Celsius)--------hot wash—hot wash—cold wash—drying.

Final process:-

Dye Padding—drying in hot flue drier---chemical padding---steaming—cold wash—oxidation—soaping—hot wash-hot wash –cold wash—drying and batching for finishing.

(For Fabric neutral PH if required slight acetic acid can be taken in last washing tank)

Jigger Dyeing machine:-

For Drill cotton Quality (For 100 kg lot). Order:-Local Quality

I) Sulphur Black dye (Powder) =6-8% Sodium Sulphide=1.5 part of dye quantity. Common salt=10 kg Soda ash=2 kg First Dye-2 Turn (Room Temp) Sodium sulphide=2Turn (Room Temp) +4Turn (Boil) + Common salt=4Turn (Boil) (Salt Addition in two installment) + Soda ash=4Turn (Boil) (Soda Addition in two installment)

II) Oxidation:- Hydrogen Peroxide=2 gpl Acetic acid=1 gpl (50-55 degree Celsius, 4Turn running drain)

III) Soaping:- Soap:-0.5 gpl Soda ash=0.5 gpl (80-85 degree Celsius, 4turn running drain) Hot wash—2Turn---Hot wash=2Turn (Fresh water) ---cold wash—unloaded.

Final process: -

Dye drain---cold wash---oxidation---soaping—hot wash—hot wash—cold wash—Unload.

Soft Flow Machine sulphur black recipe:-

For Knitting Single Jersey Cotton Fabric (GSM=100):- For 150 Kg lot

I) Dyeing Recipe:- Sulphur Dye=14.700 kg Sodium Sulphide=14.700 kg Common salt=7.5 kg Soda ash=1.5 Kg (Dyeing at boil)

II) Oxidation Recipe:- Hydrogen Perioxide:-1 liter Acetic acid:-2.5 Kg (55-60 Degree Celsius)

III) Soaping Soap =0.5 gpl Soda ash=0.5 gpl (Boil)

IV) Hot wash—hot wash—cold wash—hydro exacter—drying.

Final Process:-

Dyeing---cold wash---oxidation—soaping---hot wash---hot wash—cold wash—hydro exactor---drying. (Washing can be increased if color bleeding is observed)

First lab trail has to taken then go for bulk trail. This article has been written in good faith just sharing our experience in production area in different machinery section.

New trends in garment dyeing

Abstract

The garment industry today plays a vital role in meeting the quick challenging demands on the fashion market. The production of short run repeat orders relatively low skill input , low reject rates ,Many complex design, unique wash, value addition etc.,The most garment dyeing enable to be carried out using simple relatively inexpensive equipment with modest space requirement with out effluent production.

However, we are exploring new garment finishing system that can be used in conjunction with garment dyeing. A wide variety of dyes may be used to create unique look on garment. Garments are dyed with direct, reactive, sulphur, pigments.Sulphur and pigments are mainly used for getting ‘worn out looks’. Smart colorants are those which respond to different in environmental condition. This paper focuses on garment dyeing ,washing produces special effects like flat look denim, quick wash denim, tinted denim, grainy look denim, sand blasting. New development like laser technology, toneless stone wash effect, ion wash, mud wash, ozone fading, water jet fading etc., which are all the topics discussed in this paper

Introduction

As the fashion trends keep on changing, no one can predict quite in advance what sort of colors will run as far as garment sale is concerned. In order to be able to sense the market trend and to cut down the delivery time, the general trend is to defer the finishing after the garment is made. In such a situation, it is possible that the color in demand can be used for garment dyeing and subsequently the garments could be finished to have required resistance to wrinkles and dimensional stability. The dyeing of cotton in garment form is increasing in importance.

Smart colorants for garments:

Smart colorants are those, which respond to differences temperature or light and environmental conditions. They are called smart because they sense conditions in their environment and respond to those conditions. Initially, smart colorants were developed for specialized applications but now have become available for application on textiles / Garments. Smart colorants can be classified into three categories.

Photo chromic color:

Fabric color changes when exposed to sunlight or other source of UV radiation.

Thermo chromic color:

Fabric color changes with temperature

Glow – in – the dark color:

Fabric color glows in dark.

Uses

• On garment to create novel products and promotional items like T-Shirts
• On fabric/garment to print company logo/brand name to prevent duplication
• On garment for party wear, night clubs etc.
• Thermometers and temperature indicators.
• Security printing. • Food industry to indicate temperature of packaged food.

Photo chromic color:

Photo chromic color changes from clear when indoors to color when taken out-doors. The phenomenon produced in Photo chromic materials is called photochromism, where the change in color is due to incident light. Specifically, they exhibit color in response to exposure to sunlight or other source of UV radiation. UV light changes the chemical structure of the photo chromic material and makes it absorb color like a dye. It then reverts to a clear state when the UV source is removed.
However, to date, photochromism is most important for optical switching data and imaging systems, rather than in textile applications.

Application of photo chromic colors on garment:

Americos photo chromic colors are plastisol based ready to use off-white liquid. When exposed to UV radiation, color appears. These colors are available various hues. Photo chromic colors can be applied on garment by three methods:

• Spray
• Brush
• Screen Print

In all the above methods, photo chromic colors are directly applied on garment and cured at 1500C for 30-90 seconds.

Thermochromic colors:

Color changing inks were introduced during the 1970s with novelty items such as cups that change color when not liquids such as coffee or tea are poured in to them. Color changes of thermo chromic pigments are induced by a temperature change. When temperature rises to a specific temperature, the color changes. The color starts fading back to the original color as the pigment is cooled down.

Application of thermo chromic color on garment:

There are fifteen thermo chromic colors like Americos Red, Magenta, Vermilion, Orange, Yellow, Yellow Green, Charm Green, Sky Blue, Turq Blue, Dark Blue, Violet, and Black.

The temperature interval available from 0OC to 70OC. Specific demand can be set up for different temperature intervals from 2OC to 10OC. By using the above colors another color can be obtained but use different colors of thermo chromic pigments with the same temperature range to create more colors. Regular pigments can also be mixed with thermo chromic pigment so that the color can be changed from one to another. At lower temperature, the color reveals matched shade. When the temperature is increased, the thermo chromic pigments start fading to colorless. It only shows color of the regular pigments. By mixing the thermo chromic pigments with different temperature ranges, the color can be varied for more than two colors like temperature ranges for 3 – color variation.

Thermo chromic colors can be applied on garment by three methods.

• Spray
• Brush
• Screen Printing.

In all the above methods, thermo chromic color are mixed with suitable binder As desired viscosity needed for application. After application, garment is dried and cured at 1500C for 5 minutes.

Glow –in – the dark color:

Glow in dark is basically phosphorescence, which can be defined as the emission of light by a luminescent pigment after excitation has ceased. Americos glow in dark colors hold it’s after – glow for up to two hours. The after glow effect is dependent on pigment concentration, surface area and the amount of radiant energy absorbed

Application of glow – in – the dark color on garment:

Americos Glow – in – the dark color can be applied on garment by three methods

• Spray
• Brush
• Screen Printing.

In all the above methods, Glow-in-the dark color is directly applied on garment And cured at 1500C for 5 minutes.
Dyeing with Different Dyes:

The growth of garment – dyeing has given rise to demands for increased productivity and efficiency. The machinery manufacturers have responded by developing new machines based on the rotary-drum principle

Exclusive Features:

High temp. Up to 140° C. Working pressure - 4 Kg./cm² Capacity - 200 kg. / 400 kg. Main Vessel & Basket - SS 316 L Motor - 10 HP., With A.C. Drive Planetary Gear Box Also can druming without bags / with bags.


Following are there dyes used for cotton garment dyeing:

a) Direct dyes.

(for low colour fastness) –for ‘fashion’ merchandise for boutique outlets. Which carries a ‘hand wash separately’ care label.

b) Reactive dyes-

(for low colour fastness) – best suitable for cotton garment dyeing. Due to good level dyeing properties and high migration, diffusion properties, both cold brand and hot brand HE and HEXL dyes can be used.

c) Vat dyes –

limited use in garment dyeing. Economical for jade green shades.

d) Sulphur dyes –

used for navies and blacks.

e) Pigment dyeing –

In conventional exhaust pigment dyeing mainly there are three steps i.e., cationisation of the garment, pigmentation and treatment with binder. The above conventional process requires plenty of water and it is also time consuming which indirectly affects production. To counter this, Zytex India Ltd, Mumbai has developed a new system in pigment dyeing called OBOS one bath one step). Following are the advantages of this system.

1) Complete dyeing is carried out in single bath.

2) Intervals between addition of chemicals is only 5 minutes.

3) Water saving, equivalent to 3 drains.

4) Dyeing time is only 80 minutes.

5) 40% time is saved.

Excellent fastness and good reproductively. The process is as follows.

a) Desizing, / Scouring

b) Hot wash

c) Cationic pre-processing.

d) Garment pH should be neutral and good absorbency.

e) Then add the following chemicals: anticreasing agent, dispersing cum leveling agent, polymeric cationising agent for cotton (Zycat PD) – runfor 20-30 mins. At 60-70 deg c.

f) Then add a range of pigment colors specially developed for exhaust pigment dyeing.(ZYpigment). Run for 30 mins. At 70 deg c to 100 deg c.

g) Add polymer based binding cum fixing agent for pigments. (Zyfix PF) then run for 30-40 mins at 30 deg c to 60 deg c.

h) Rinse, unload

i) Drying / curing for binder fixation at 90 deg c to 130 deg c for 10 mins. One advantage of garment dyeing cotton is that there will be no problem with shrinkage for the customer.

Al the above process is conveniently carried out in the new generation of rotary – dyeing machines. They are of two types.

a) Divided b) Open-drum

Accordingly the type of mechanical agitation can be selected, and fitted with a microprocessor controller and a dosing pump; they can be programmed to run through the full dyeing procedure automatically.
Among the most important chemicals for the garment dyeing sector are lubricants for preventing marking by creases formed during running or lying, bleaching and scouring streaks and chafe marks, which are some of the most common quality impairing problems of garment dyers and jean washers.

Different Color Depth Fabric:

To cut processing time, effluent load, and minimum damage to fabric and; minimum use of chemical, there are different depth of indigo in 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 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/ over dyed look on garment, garment processor is using an additional process of tinting/over dyeing, 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.

Recent Developments in Garment Processing:

It was considered impossible to obtain wrinkle free finish on white garments in wet processing. It was rather difficult to achieve wrinkle free performance with minimal yellowing and strength loss, and good handle. Achieving any of these attributes implied compromising on the other two. Now, thanks to recent product developments, it is possible to strike a good balance between these features, with the help of a wrinkle-free system containing an inbuilt catalyst and softener.

Also, microencapsulated fragrance finishes are becoming important value-adds in garment processing. When these finishes are applied on to the garments, in the same way as perfumes, the active ingredients get gradually released on to the skin.

Laser-based processing is another emerging versatile technology in denim finishing, which permits application of laser-based photographic effects, abrasion effects and new laser-based stone washes.
Recent developments have also made it possible to use antimicrobial finishes, water and oil-repellent finishes, flame-retardant finishes, antiozonate finishes, UV absorber finishes and coatings individually, and in combinations of two or three.

Avoiding the Environmental Hazards of Garment Processing:

Textile processing uses vast amounts of water, chemicals and energy, and therefore, has considerable effects on the environment in the textile manufacturing regions. The effluents from wet processing of garments cause similar environmental hazards as fabric processing. Moreover, the garment processing sector is highly unorganized; effluents are released in to municipal drains causing environmental problems.

Apart from investing heavily in effluent treatment, pollution loads can also be reduced by 30-50%, by using pollution prevention techniques. Here’s list of wheat can be done.

1) Reduce wastewater volume by:

• Good housekeeping

• Counter flow processing

• Re-using process water,

• Automating machinery,

• Processing alternatives

i.e., green cleaning over conventional dry cleaning where perchloroethylene is replaced by CO2 in liquid state, or by organic hydrocarbons, ozonated water and ultrasonic cleaning.

2) Reduce the amount of dyes and chemicals used by:

• Good housekeeping

• Process optimization,

• Recovery and re-use of process chemicals,

• Automation of machinery,

• Replacement of conventional chemicals with eco-friendly chemicals.

The dyestuffs, pigments and chemical products ‘saved’ by these methods mean less effluent in the system. Textile processors have begun focusing on pollution reduction, on a process-by-process basis. But we need to think about his holistically, so that, at each step of the processing cycle, we make decisions that impact down stream process, beginning with product design and ultimately involving the consumer.

Global needs cannot be met by concentrating only on the product design and products effects on downstream processing. We should also examine the manufacturing process, in terms of containers, machine parts, drums, mix tanks, etc, to reduce solvent loss and quality. Such thinking should extend even to the consumer’s use of products, in terms of after-market treatments, cleaning solvents, use conditions, installation and maintenance and so on.

onclusion

Garment dyeing brings with it a plethora of possibilities, which can help the textile industry earn immense benefits. However, lack of vision and a few temporary hurdles are preventing it from playing its rightful role in textile processing. We need to take proactive measures and adopt a holistic approach to tackle the shortcomings, after which garment-dyeing will be all set to contribute a lion’s share to the success of the Pakistan textile Industry.

INDIGO: THE MYSTERIOUS DYE

Introduction Indigo dye is an important dyestuff with a unique shade of blue color. The natural dye comes from several species of plant .The dye gives a brilliant and eye-catching blue color to the fabric. This color partially penetrates the fabric but then also imparts surface blue color to the fabric. The word indigo is derived from the Latin Indicum and the Greek indikon meaning 'blue dye from India' or being more specific-'Indian substance'. Natural Indigo is the oldest known dye to mankind. When the synthetic substitute of the dye was not invented, all blue textiles were used to be dyed with indigo. These included the blue serge uniforms worn by the British police force and hospital staff, as well as military personnel and workman's clothes worn by millions of people, inspiring the term 'blue-collar worker'. The natural production of indigo is extracted from the leaves from a variety of plant species including indigo, woad, and polygonum. Only the leaves are used since they contain the greatest concentration of the dye molecules. Structure Indigo is a dark blue crystalline powder that melts at 390°–392°C. It is soluble in chloroform, nitrobenzene, or concentrated sulfuric acid, but not soluble in water, alcohol and ether. The chemical structure/formula of indigo is C16H10N2O2. Indican is colorless and soluble in water which is a by-product of indigo. Indican is hydrolyzed to glucose and indoxyl .Indigo is converted to indoxyl by mild oxidation. When indigo is decomposed simple compounds like aniline and picric acid are produced . Reduction of urea to indigo white is of great importance The indigo white after it is applied to the fabric is reoxidized to indigo. History Indigo is one of the oldest dyes that was used for textile dyeing and printing. Asian countries like India, China and Japan had used indigo as a dye for centuries. The ancient civilizations in Mesopotamia, Egypt, Greece, Rome, Britain, Peru, Iran, and Africa had the knowledge about the dye. Since Neolithic times in Europe this dye is being used It was highly prized for its colour and light fastness .Until the end of the 19th century; the sole source was from plants, woad (Isatis tinctoria) and Dyer's Knotweed (Polygonum tinctorum) in temperate climates and Indigofera species in the tropics. Woad was widely grown in Europe, making some regions, especially Toulouse (France) and Erfurt (Germany) making them economically very prosperous. It was used to make a woad vat for dyeing with indigo from India after that period It belongs to the legume family and its three hundred plus species have been identified. In ancient times, indigo was considered a precious commodity because plant leaves contain only about small amount of the dye (about 2-4%). Indigo remained a rare commodity in Europe throughout the Middle Ages; woad, a dye derived from a related plant species, was used instead. Indigofera tinctoria was originally domesticated in India; it is mentioned in manuscripts dating from the 4th century BC about its origin in India. The blue serge uniforms worn by the British police force and hospital staff, as well as military personnel and workman's clothes worn by millions of people were dyed by indigo dye, the term blue collar worker has been inspired from this aspect .It was a luxury item imported to the Mediterranean from India by Arab merchants. The Portuguese explorer Vasco da Gama in late 15th century discovered a sea route to India. This led to the establishment of direct trade with India, the Spice Islands, China, and Japan .It resulted in avoidance of the heavy duties imposed by Persian, Levantine, and Greek middlemen on the importers and also the lengthy and dangerous land routes which had previously been used for transportation . As a result, the importation and use of indigo in Europe rose significantly. In the 19th century, the British obtained much indigo from India .When the synthetic substitute of indigo was invented the demand for natural indigo dropped, as a consequence for many indigo farmers the raising of indigo became loss making business. Cultivation Since synthetic indigo dye is being used ,use of natural indigo dye has almost became extinct , but in recent years, the demand for natural dyes has been increasing in many countries again, because of health and pollution effects and a revival of interest in the relationship between dyes and culture. In present time, indigo is still cultivated for dye on a small scale basis in India (particularly in the northern part of Karnataka) and in some parts of Africa and Central America. It is frequently grown as a secondary crop. Dissemination is usually by seeds which are sown at first in seed beds or directly into the field. Germination takes about 4 to 5 days. When the plants are about 4 to 5 months old and starts flowering then the branches are harvested. At 3 to 4 months intervals three times a year the plants could be continued to be harvested. The total life span of the plants could range from time period 2 to 3 years. Processing A. For Natural Indigo Dye • The leaves of indigo go through a process of fermentation and then oxidized to yield the blue dye. Traditionally fermentation was carried out by bacteria. The harvested plants first of all, packed into tanks and is covered with water. After a few hours of soaking the plants in water, the leaves become saturated and fermentation begins. A thick layer of bubbles and foam forms at the top of the tank. The process can be so vigorous that planks are placed on top of the tub to keep the plants in. This process can take up to a day and a half to complete, but the timing has to be perfect .The indigo makers will smell and taste the fluid to check whether the dye is ready or not. Even if an hour is taken extra it could ruin it. As soon as the liquid tastes sweet and is a dark blue colour, it is drained off into another vessel at a lower level, leaving the plants behind. The liquid now formed contains indoxyl. • To stimulate oxidation of the indoxyl the liquid is stirred continously for many hours for it requires oxygen for oxidation. On alternative basis people will get into the vats to tread up and down to stir it up. After sometime the liquid turns a yellow-brown colour with floating dark blue patches. The solution is left to rest and the insoluble indigo settles to the bottom of the tank as a bluish sludge. To remove impurities and to stop the enzyme reaction which made the indigo the water is drained and filtered. The sludge is then dried to produce indigo 'cake' which is cut into cubes or made into balls. • The Japanese used another method of extracting indigo from the polygonum plant, the plant is mixed with wheat husk powder, limestone powder, lye ash, and sake in this method of extracting indigo. The mixture is allowed to ferment for about one week to form A dye pigment which is called sukumo is formed from the fermented mixture. • The indigo was used to be dissolved in stale urine in Europe as a pre-industrial process for dyeing in earlier times .The water-insoluble indigo is converted to soluble substance known as indigo white or leucoindigo by urine, which produces a yellow-green solution. After the indigo white oxidizes the fabric turns into blue color fabric. • Another preindustrial method, used in Japan, was to dissolve the indigo in a heated tub in which a culture of thermophilic, anaerobic bacteria was maintained .Insoluble indigo could be converted into soluble indigo white by certain specific species of bacteria when they generate hydrogen as a metabolic product. Cloth dyed in such a vat was decorated with the techniques of shibori (tie-dye), kasuri, katazome, and tsutsugaki. B. For Synthetic Production of Indigo Dye • The synthesis reactions are conducted in large stainless steel or glass reaction containers.These containers hold jackets to permit steam or cold water to flow around the batch, as the reactions progress. On account of complication of these chemical processes, the dye is usually made in batch quantities. The Germans have invented methods for continuous process manufacturing. • The first commercial method of producing indigo was based on Heumann's work. In this process, Nphenylglycine is treated with alkali to produce indoxyl, which could be then converted to indigotin by contact with air. But the amount of dye produced by this process is very less. More competent method, synthesis utilizes anthranilic acid. A alternate of this method (which is widely used) involves the reaction of aniline, formaldehyde, and hydrogen cyanide to form phenylglycinonitrile. This material is thereafter hydrolyzed to yield phenylglycine which is then converted to indigotin. Currently a method which uses sodamide with alkali to convert phenylglycine to indoxyl is used. Sodamide reacts with excess water, thus lowering the overall reaction temperature from almost 570°F (300°C) to 392°F (200°C). Efficient reaction process is achieved through it. • After completion of the chemical reaction processes, the finished dye has to be washed to remove impurities and then dried. The dried powder then can be packed in drums or reconstituted with water to form a 20% solution and filled in containers. Usage • Indigo blue is the primary color of blue jeans in the west, its importance as result is increased in present time. In the United States indigo is primarily used to dye cotton clothes and blue jeans .Over one billion pairs of jeans around the world are dyed blue with indigo. Deep navy blue colors on wool are produced by indigo dye. • The Romans in earlier times, used indigo as a pigment for painting and for medicinal and cosmetic purposes. It was a luxury item for Arabs which was imported to the Mediterranean from India by Arab merchants. • Indigotinesulfonate is used as a dye in renal function testing and as a reagent for the detection of nitrates and chlorates .It is also used in the testing of milk. • Indigo is also used as a food coloring under the name FD&C Blue No. 2. • It was the original dye of the "Levi's" blue jeans, a trademark color for durability. It is the only natural blue dye that is permanent in nature. • On many instances from Europe to the Arab world, historical use of blue to stain skin for war, religious and social rites were found. • Indigo in combination with resist techniques create decorative wooden items. • In certain cultures indigo dye is also used for craft purpose such as on paper, leather and on silk. The Future Scientists all over the world are carrying out research programmes on inventing a method of producing indigo dye which is less hazardous to health .Using biocatalysts in the dye reaction process might work out for producing environment friendly dye. By making through a biological route, indigo dye would become one of the first high-volume chemicals by the biological route. Genencor International, of Rochester New York, is experimenting on a process to produce indigo using biotechnology. However, at this stage the technology is expensive and production costs might be prohibitive. The natural dye comes from several species of plant, but nearly all indigo produced today is synthetic in nature.

COME, ENTER THE WORLD OF DENIM JEANS

Come, Enter the World of Denim Jeans

‘Denim’ has been synonymous with ‘jeans’ for time immemorial. It is not possible to separate one meaning from the other. Somehow, when you say denim, people automatically assume that you’re talking about denim jeans, although there are plenty of other types of denim-wear out there. Denim jeans are just the most commonly worn denim garments. As such, they have reached an iconic level.

Denim jeans are particularly important to young people of today. They are a symbol of youth, vibrancy, and utility. As such, denim jeans can be found at just about every retail store and discount mart on the market. Denim jeans have become ingrained in American culture. However, denim jeans did not get their start in America. In fact, nobody really knows just where denim jeans come from. Rumors have them originating in France, while others tout England or Italy as the birthplace of the denim jeans. What we do know is that denim jeans were originally designed for the laborer, who needed trousers that were sturdy and comfortable.

Did you know that the word ‘denim’ actually refers to a color and not a type of fabric? The color indigo is mixed with a host of other colors such as blue, gray, white, or black to give you the myriad of colors that you find denim jeans available in today. These are special hues that are found only with the denim jeans; hence, the ‘denim’ came to mean jeans.

Denim jeans use about half of the total global cotton output production, which by any standard is a huge figure. This would indicate easily how famous, popular and in demand this particular garment is to society. Initially, denim jeans were only used as casual wear; however things are changing and now denim jeans are entering the boardrooms of large corporations in the form of ‘casual-formals,’ Casual-formals are specifically designed for those people to whom comfort and elegance mean the same thing.

Answering to the ever-growing demand for denim jeans, there is a mushrooming effect on the growth of denim industries all over the world as well as in designer collections. The popularity of denim jeans being what it is today, designers have gone crazy with their denim lines. Denim jeans with a designer label demand exorbitant prices. After all, unlike other garments, denim jeans can fit in anywhere.

The denim jeans’ popularity has had a ripple effect with other items that complement their use, such as denim handbags, shirts (both for men and women), skirts, shorts, shoes and sandals, the list could go on. It seems that wherever you turn you can find something to wear or use that is made of denim. However, far from suffering from over-exposure, the popularity of denim jeans is growing at a phenomenal rate.

Bio-cotton has Colours for the Future

Bio-cotton has Colours for the Future Why bio-cotton? Various interest groups are strengthening the trend towards environmentally friendly production methods. Among these are farmers, consumer organisations and companies which are suffering from increasing competition and environmental regulations. For all of these, the effects of intensive cotton cultivation cannot be ignored. The growing interest of consumers in ecologically produced foodstuffs is currently spreading to other areas of ecological farming, amongst which is the ecological production of cotton fibers.

In cotton cultivation, controlled biological growing is still relatively new. Bio-cotton was first cultivated at the end of the eighties in Turkey. Meanwhile, cotton is cultivated in a controlled biological environment in 22 countries, among which are Egypt, Benin, Burkina Faso, Mali, India, Peru, Tansania, China and the USA.

What is bio-cotton?

Cotton in controlled biological agricultural systems is cultivated according to previously defined standards. This system forbids the use of toxic and persistent non-bio-degradable chemical-synthetic pesticides and fertilisers. This way the soil and the groundwater are not further contaminated. The use of genetically modified organisms is also forbidden. The production of bio-cotton has many advantages:

# As no chemical-synthetic fertilisers and sprays may be used, there is practically no more contamination of the groundwater and the farmers have fewer health problems. # Thanks to biological cultivation, the soil fertility is maintained and the crops remain stable over many years. # Thanks to subsidies and bio-premium, small farmers can also manage to live without requiring credit. # The purchase guarantee gives the farmers a feeling of self-worth and ensures them a regular income.

Cultivation and processing of biocotton during cultivation, no chemical-synthetic fertilisers and pesticides are used and genetically modified seeds are forbidden. Bio-cotton is cultivated alternately with other field crops and fertilised with dung and compost, and this maintains soil fertility.

Due to its natural characteristics, cotton became the most-processed and most-used textile fibre. It can be processed at will and is easy to dye and print on. Cotton materials can therefore always be manufactured in any desired fashion colour and colour shades and with practically any desired colour fastness. Wearing and care characteristics can be improved by using wash-resistant, fixable finishes or by chemical modification of the cellulose.

Nowaday cotton clothing can be wrinkle resistant, sanforized, low maintenance, dirt and water-resistant and have permanent leg-line creases. There is flame-resistant protective clothing or curtains made of cotton materials, which, in extreme conditions, are resistant to decay and mildew.

Finishing increases value and quality During these processes, the look and the serviceability of textile are improved, providing added value. Without finishing, cotton wrinkles because cellulose fibres are non-elastic. SANFOR is the best-known trademark for shrink proof finishing. It prevents from shrinking and guarantees form stability during washing.

# Mercerizing : By the treating the cotton with caustic soda and stretching it at the same time, section becomes round. The result is a long-lasting shine and softness despite washing and dry-cleaning.

# Calendering is a special method of pressing which more or less shine, smoothness and density.

# Water Repellent Finishing, such as a impregnating : By soaking in suitable chemicals such as silicon, cotton textiles become water-repellent. But it is necessary to repeat this process after washing.

# Easy-care characterstics obtain by using high-grade finishing (artificial resin or cross-linking): labeled as non-iron, minimum-iron, mini-care, wash & wear. Cotton textiles finished in this way are easy-to-wash, hardly shrink, dry quickly, need little or no ironing and are wrinkle-resistant.

Bleaching make it possible to dye and to print textiles with light, mellow and bright colours chemically decomposing the natural colour dye of the fibre. Finishing improves the feel and makes the material soft and pliant, such as for towelling, baby clothing and daywear. Other finishes give a full, firm feel, for instance for tablecloths or napkins. Dyeing and printing is possible with bright colours as cotton easily absorbs dyestuffs.

For the embroidery machine, there are few points to be taken into consideration. Optimal pre-requisites for fabrics are strength, elasticity, yarn twist S/Z, number of twists, storage temperature, processing temperature of approx. 22°C and a high degree of humidity of 6S to 80%.

ANTI BACK STAINING METHOD FOR DENIM

A Novel Anti Back Staining Method for Denim

Garments: A Cost-effectiveProcess

Abstract:

Denim and its various items like pants, shirts, jackets, belts, caps, etc, are the most preferred clothing for today’s youth. This study discusses compositions and methods of reducing or preventing back staining of indigo dyes on the weft yarn and pocket of denim garments. The dye, as it is removed from the denim material, post treatment with cellulase or by a conventional washing process may cause ‘back staining’ or ‘re-deposition’ on the denim material; e.g.: re-colouration of blue threads and blue colouration of white threads, resulting in less contrast between the blue and white threads.

Introduction:

Denim garments are looked at as a major trend setter by our youth. The spread of denim culture all over the world brought with it a trend of fast changing fashions. One after another several washes were introduced such as stone wash, acid wash, moon wash, etc. Over the last decade, India has probably seen the most dramatic and exciting changes in the washing of denim garments. As per the denim garment export market, this high quality garment has superior aesthetics and great value for price. In terms of the quality aspect, back staining plays a vital role in improving the appearance of the denim garment. Back staining: Back staining implies soiling of the weft thread and the pocket lining by detached indigo or its reduced leuco form. Back staining mainly occurs during desizing or stone washing or enzyme stone washing.

Chemistry of Back Staining:

During stone washing or enzyme washing, cellulose is degraded and indigo dye is released. For instance, the cellulase enzymes are temporarily bound to the cellulose by means of an anchor. This gets split in terms of 1,4-β glycoside composition. After this process it is made available for further hydrolysis reaction.

Enzyme-catalyzed hydrolytic dissociation of cellulose

This reaction is much more complicated in detail, as the customary cellulase consists of several components. Below you can see the dissociation of cellulose in detail:

Hydrolysis of Cellulose: • Endo Gluconases: By means of the endo gluconases the cellulose is dissociated in a statistically distributed sequence. • Exo Gluconases: The exo gluconases dissociate the cellulose chains into glucose molecules from the unreduced end. • Cellobiohydrolasis: Separation of cellobiose (double bond glucose molecule) from the unreduced end of the cellulose. • β- Glucosidasis: Dissociation of the cellobiose into glucose molecules.

As seen from the picture, the cellulase is degraded hydrolytically by cellulases partially until it becomes glucose. The glucose is partially able to reduce the indigo, both on the fibre and in the treatment liquor. This reduced form has low affinity to cellulose fibre and thus soils the weft thread and the pocket lining. This is also assisted by alkaline conditions and the temperature of the wash bath.

The acid cellulase enzymes have a strong effect on cellulase hydrolysis and create more glucose formation, resulting in increased back staining of the denim garment. Neutral cellulase has its optimum pH at 6-8 at temperatures of 50 – 60°C. Compared to acid cellulase they have a less negative effect on the tensile strength; hence there is less back staining.

As a whole, obtaining a good contrast between the blue and white yarns is often described as minimised back staining. The contrast is the difference between the blueness of the blue yarns and the whiteness of the white yarns. But this is difficult to quantify. Therefore, back staining can be quantified by measuring the re-deposition of indigo on white denim.

Anti Back Staining:

In order to avoid such back staining, which will reduce the garment’s value in the world market, some anti back staining agents are used in the wash bath. These agents are added in the bath along with other chemicals associated with the respective washes. These agents are the ones capable of prohibiting the action wherein the removed dyes re-deposit themselves on the garment.

Compositions and Chemistry of the Anti Back Staining Agents:

Anti back staining agents mostly comprise of three substances - dispersing agents, chelating agents, and emulsifying agents. All these must be of a particular concentration in order to inhibit the adherence of indigo dyes on the white portions of denim garments. Most of these anti back staining agents are highly efficient in soft water, but in hard water they might be less effective and so the dyes will re-deposit. This is so because hard water contains salts, called the electrolytes (exhausting agents), which help indigo dyes to soil faster. Nowadays, anti back staining agents contain sequestering agents as well, so that they can be used in hard water. Acid liberating agents are also used along with anti back staining agents to reduce the alkaline conditions and enhance the enzyme activity.

As a latest innovation we have anti back staining agents made from polyglycol ether derivatives and polymer phosphates. This is an inbuilt sequestering agent, which can be used more effectively in hard water.

One of the safest modes of anti back staining is the enzymatical way, where some enzymes, like the cutinase enzymase and other lipolytic enzymes are also used as anti back staining agents. All these efficiently reduce back staining, but are costlier too. Some anti back staining agents are used as afterwashing agents, which have very high emulsification power.

Another way of avoiding back staining is by using oxidizing agents. According to the chemistry of back staining, it is caused by the formation of glucose during stone or enzyme washing of the denim garment. This glucose is the reducing agent and it helps the indigo dye to exist on the white part of the denim, thus reducing the contrast of the garment. Now these oxidizing agents will act on the glucose and decrease its reducing power and enable zero back staining. These are the bleaching agents such as hypo chlorites, permanganates, peroxides, etc. There are some mild oxidizing agents also, which are called Resist Salts.

These oxidizing agents will be added to the enzyme bath or the stone wash bath and will inhibit the reducing action of glucose during processing. As far as this study is concerned, some denim trials have been taken in which we found hydrogen peroxide to be a good substitute as an anti back staining agent. It has to be used in low concentrations to avoid imparting a more bleaching effect on the garment. All these tests were taken during the enzymatic processing techniques as they are mostly used in all garment industries. All these trials have been done on both the sample machines and a bulk trial has also been taken and the report of the same has been given. The results of the trials are as follows:

Results and Discussion:

Some of the trials have been taken to prove the efficiency of oxidizing agents as anti back staining agents, along with their recipe proposal and trial result. The bulk trial was also taken to check the effectiveness of the same in a mass quantity and whether it stays effective in larger baths also.

Discussion:

On analysing the oxidising agents used in this study we found that hydrogen peroxide proves to be the safest anti back staining agent than the rest. The hypochlorite imparts some yellowness after being kept for a long time and is also toxic in nature. The potassium permanganate also imparts a slightly yellower tone. But peroxide gives a brighter look and gives better results at very low concentrations. The working of the peroxide as an anti back staining agent is very simple. Say, when the denim garments are in the bath its pH will be slightly alkaline. So this helps the peroxide to start liberating nascent oxygen thereby helping in anti back staining activities. So, this way the denim garments are imparted with a good salt and pepper effect than with other anti back staining agents.

Epilogue:

The project results, samples and the photographs indicate that usage of oxidising agents like otassium permanganate, sodium hypochlorite, hydrogen peroxide in the enzyme bath provide good anti back staining properties. It was found that hydrogen peroxide was performing well as an anti back staining agent with dosage between 0.5 to 1.0%. This also proves to be the most cost-effective anti back staining agent. In both dosages it has imparted good anti back staining results. The results were compared with normal biofading enzymes treated with and without anti back staining agents. The dosage has to be worked out for different denim substrates depending upon the shade and customer requirements.