Friday, 15 August 2014

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.

Tencel Biosoft

 Lenzing introduces TENCEL®Biosoft, the first hydrophobic and home-compostable fiber leading to unique benefits for wipes and hygiene applications.
In the wake of the Deepwater Horizon oil disaster in the Gulf of Mexico in April 2010, researchers were looking for new materials for oil clean up. At that time, Lenzing started first trials for producing a new TENCEL® fiber which could be used for oil absorbency while retaining its biodegradability.
Bianca Schachtner, Project Manager New Products Business Unit Nonwoves, summarizes: “During our extensive research work, we realized that the actual benefits of the developed fiber went far beyond the original objective. In addition to having developed the first hydrophobic and sustainable TENCEL® product, the new fiber turned out to be extra soft, smooth and functional making it an ideal base for sensitive nonwovens applications.”
In wipes, TENCEL®Biosoft can be used in a variety of blends which tailor the absorbency and cleaning performance to suit a number of different functions from full oil absorbency through to specific lotion management. In topsheets of hygiene products, excellent liquid strike through times and wet back properties ensure a comfortable dry feeling to the skin. TENCEL®Biosoft meets the performance of commercially available synthetic products and adds a botanic value as Lenzing’s cellulose fibers are made from the renewable raw material wood sourced from responsibly managed forests. Based on natural resources, TENCEL® and TENCEL®Biosoft are biodegradable and meet even the enhanced standards of Vincotte Home compostability. 
TENCEL®Biosoft will be presented at this year’s man-made fiber congress in Dornbirn on 20th September 2012. “As a leader in fiber innovation, we at Lenzing are constantly developing new fiber types paving the way for new end uses for our sustainable fibers. TENCEL®Biosoft revolutionizes nonwoven products along the supply chain,“ says Wolfgang Plasser, Vice President and General Manager Business Unit Nonwovens. “Lenzing is delighted to launch TENCEL®Biosoft in Dornbirn. The botanic fiber makes the difference from the very beginning!”

Sunday, 27 July 2014

Growth and Development of a Cotton Plant


The cotton plant has perhaps the most complex structure of all major field crops.  Its indeterminate growth habit and extreme sensitivity to adverse environmental conditions is unique.  The growth of the cotton plant is very predictable under favorable moisture and temperature conditions.  Growth follows a well-defined and consistent pattern expressed in days.  Another useful and more precise way to assess crop development relies on using daily temperatures during the season to monitor progress (Table 1).  The heat unit concept utilizes accumulated hours above a critical temperature rather than calendar days in describing growth and development.  The growing degree days (DD) concept is based on a developmental threshold above which the crop grows.  Below that temperature is where little or no development occurs.  For cotton, the threshold temperature is 60˚F; therefore, the degree days are referred to as “DD60’s”. The basic formula for calculating heat units involves averaging the maximum and minimum temperatures for each day and subtracting the threshold temperature.  Calculation of the accumulated heat units and knowledge of the heat unit requirement for any particular growth stage can be used to explain and predict the occurrence of events or duration of stages in crop development (Kerby et al., 1987; Landivar and Benedict, 1996; Oosterhuis, 1990).
Table 1. The average number of days and heat units required for various growth stages of cotton in the Mid-South.
Growth Stage
Days
Heat Units – DD60s
Planting to Emergence
4 to 9
50 to 60
Emergence to First Square
27 to 38
425 to 475
Square to Flower
20 to 25
300 to 350
Planting to First Flower
60 to 70
775 to 850
Flower to Open Boll
45 to 65
850 to 950
Planting to Harvest Ready
130 to 160
2200 to 2600
Modified from Oosterhuis, 1990
Stages of Growth
The developmental phases for cotton can be divided into five main growth stages:  (1) germination and emergence (2) seedling establishment (3) leaf area and canopy development (4) flowering and boll development and (5) maturation (Fig. 1).  The transitions between these stages are not always sharp and clear.  Each stage may also have different physiological processes operating within specific requirements.  If producers are aware of these stage-dependent differences in cotton growth and requirements, then many problems in crop management can be avoided, which will result in higher yields and profits.


growth-fig-1
Figure 1. Seasonal development of cotton in the Mid-South with a May 1 planting date, showing typical production patterns of squares, bolls and open bolls (Oosterhuis, 1990, with permission ASA).
Root Development
Under favorable germination conditions, the radicle (root) emerges within two to three days.  The radicle becomes the taproot that grows downward into the soil.  The taproot penetrates the soil rapidly after germination and may reach a depth of up to 10 inches or more by the time the cotyledons unfurl (5 to 7 days, 50 DD60s) (Fig. 2).  Root development during the early vegetative stage may proceed at the rate of 0.5 to 2.0 inches per day, depending on soil temperature and moisture conditions (Huck, 1970; McMichael, 1986). 
growth-fig-2 
Figure 2.  Stages of germination and seedling emergence (Oosterhuis, 1990, with permission ASA).
The roots may be 3 feet deep in some soils when the above ground portion of the plant is only about 14 inches (Fig. 3). The taproot may penetrate the soil from less than 1.5 feet to as much as 9 feet while the lateral roots remain fairly shallow, less than 3 feet (McMichael and Quisenberry, 1993). On deep alluvial and irrigated soils in California, roots reach a depth of 3 to 4 feet when the young plants are only 8 to 10 inches high, with a final depth at maturity of 9 feet (Grimes et al., 1972).  The bulk of the root system is located in the upper 3 feet, but this is dependent upon the soil moisture, soil physical structure and vigor of the individual plant (Taylor and Ratliff, 1969; Pearson et al., 1970; Taylor and Gardner, 1983).  The total root length continues to increase as the plant develops until the maximum plant height is achieved and fruit begins to form.  Total root length begins to decline as older roots die.  Furthermore, root activity begins to decline as the boll load develops and carbohydrates are increasingly directed toward developing the fruit (McMichael, 1986).
growth-fig-3

Figure 3.  Early-season root development of cotton (Oosterhuis, 1990, with permission ASA).
Vegetative Development
Under favorable conditions for germination, cotton seedlings emerge five to ten days after planting or after 50 to 60 DD60s are accumulated.  The fully expanded cotyledons are 1 to 2 inches above the soil surface and are arranged directly opposite the main stem.  The cotton plant has a very prominent main stem, which results from the elongation and development of the terminal bud or apical meristem.  The main stem consists of a series of nodes and internodes and has an indeterminate growth habit (Fig. 4).  Much of the early development of the cotton plant is directed by the development of a substantial root system while growth of the first true leaves is relatively slow.  The number of nodes and the length of the internodes are influenced by genetics and environmental factors such as climate, soil moisture, nutrients, disease and insects.  The appearance of a new node for relatively non-stressed cotton occurs after an additional accumulation of 50 to 60 DD60s (Kerby et al., 1987; Oosterhuis, 1990).
 
growth-fig-4
Figure 4.  The basic structure of a cotton plant includes the main stem, which is made up of a series of nodes and internodes, and two types of branches, vegetative and fruiting branches (NCC, 1996).
The developmental rate of a new node is significantly slower when the plant is water stressed.  Typically this produces shorter stature plants.  Nodes give rise to main stem leaves and branches.  Main stem leaves and branches are spirally arranged on the stem in a three-eighths phyllotaxy above the cotyledonary node.  Two types of branches are produced: monopodial are the vegetative branches and sympodial are the fruiting branches.  Monopodial branches are structurally similar to the main stem.  Growth is from a single terminal bud and tends to grow in an upright position.  Sympodial branches are produced by the main stem and monopodial branches and grow at an acute angle to the main stem.  Every sympodial branch has a main stem leaf associated with the branch. As the branch extends from the main stem, each new fruiting node has an extending leaf and a fruiting structure or square at each node.  Elongation of the internode behind the flower bud and leaf causes them to extend away from the main stem.  The development of this branch terminates in a square, but a second leaf and square develop in the axil of the first leaf and similarly extend away from the first leaf and square by internode elongation.  Repetition of this process produces several squares and leaves resulting in the typical zigzag appearance of the fruiting branch.  The flowers are opposite the leaves on the sympodial branches and develop more rapidly than monopodial branches.
Final plant height is also a function of the extension of main stem nodes. Within cotton varieties, the seasonal total numbers of main stem nodes is strongly influenced by determinacy and growing environment. Cotton breeding and selection for earliness has favored shorter statured, more determinant cotton varieties. However, management factors such as excessive nitrogen fertilizer and excessive square loss from insect feeding can cause even moderate stature plants to grow excessively tall and rank (Siebertet al. 2006).
Reproductive Development
Signs of reproductive growth begin to appear about four to five weeks after planting with the formation of the floral buds or squares in the terminal of the plant (Table 1). Cotton has a distinctive and predictable fruiting pattern. Once fruiting begins, fruiting branches tend to be produced at each successive main-stem node. The first fruiting branch is often produced at the sixth or seventh node on the main stem. Approximately three days elapse between fruit on a given fruiting branch and the same relative position on the next higher branch. The time interval for the development of two successive fruiting forms on the same sympodial branch is approximately six days (Fig. 5). Squaring is followed about three weeks later by flowering and the start of boll development. The time requirement for a square to develop into a white flower is not influenced significantly by external conditions or plant stress. Throughout the remainder of the season, the cotton plant, due to its indeterminate growth habit, will continue adding vegetative growth at the same time as the reproductive development. The occurrence of the first position white flower moves closer to the terminal of the plant as the developing bolls become the major sink for photosynthate, which in turn also results in the slowing of new node or square development (Robertson et al., 2007a).
Table 2. Timing of various events during square development relative to the flowering date of an individual fruiting structure.
Days
Before
Flower
Size of Bud
Comments
40
Microscopic
Square initiation can occur as early as 2nd true leaf expansion.  Hot weather induces four-bract squares, cool weather delays square initiation.
32
Microscopic
Lock numbers determined.  Carbohydrate stress decreases number from 5 to 4.
23
2 mm PHS
Ovule number determined.  Carbohydrate stress decreases potential seed number.
22
2 mm PHS
Pollen cells divide.
19
3 mm MHS
Pollen viability reduced by high nighttime temperatures.
5
13 mm
Squares start expanding rapidly
3
17 mm
Fibers begin to form
0
Flower opens White flower
Pollen sheds and fibers start to elongate.  Extremes of humidity or water disrupts pollen function.

Modified from Stewart, 1986
growth-fig-5
Figure 5. Expected flowering interval in days beyond first flower illustrating the three day age difference in flowering dates of the same fruiting position on the next higher fruiting branch and the six day difference in age between fruiting positions on the same branch (Oosterhuis, 1990, with permission ASA).
The boll develops rapidly after fertilization and reaches its full size within three weeks (Fig. 6).  An additional four to five weeks are required for boll maturation.  Seeds attain their full size about three weeks after fertilization, but do not reach maturity until shortly before the boll opens.  Fibers attain their full length in about 25 days after fertilization with the maximum growth rate occurring during the first 10 to 15 days of this period.  Thickening of the fiber begins at about 16 days after fertilization and continues until the boll is mature.
growth-fig-6
Figure 6. Although bolls are full size 21 days after flowering, fiber and seed development requires an additional 28 to 35 days (NCC, 1996).
Fiber thickening occurs by the daily deposition of consecutive layers of cellulose on the inner wall of the fiber in a spiral fashion.  The degree of thickening and the angle of the spirals affect fiber strength and maturity.  Fiber elongation and maturity can be impacted by numerous factors from fertilization to maturity (Table 3).  Until the boll opens, the fiber is a living cell, but upon opening the fiber is exposed to the air and soon dries out and becomes twisted (Seagull, 2001).  In addition to the long fibers, most commercial cultivars (excluding Gossypium barbadense) have very short white or colored fibers on the seed called linters or fuzz fibers.
Days
After
Flower
Event
Primary Factors Influencing the Event
-2 to 12
Fiber density on seed surfaceTemperature and carbohydrate status
0
Pollen shedTemperature and relative humidity
0 to 3
Rate of fiber initiationTemperature and potassium status
0 to 3
Pollen tube growth and seed fertilizationTemperature and relative humidity
1 to 14
Boll abscissionPlant water and carbohydrate status
3 to 25
Fiber length and seed numberTemperature and potassium status
15 to 45
Fiber cellulose (fiber thickening)Temperature
25 to 50
Protein and oil accumulationTemperature, plant water, nitrogen and potassium status
49 to 50
Boll openingTemperature and relative humidity


Table 3. Timing of various events during boll development relative to flowering and primary factors influencing the event.
Cotton quality is defined by the length, maturity, strength and micronaire of the fiber.  These qualities are determined by the genetic makeup of specific plant varieties, the climatic conditions experienced by the crop, and the management of the crop through production and harvest (Table 4).  For example, bolls maturing late in the season, when temperatures are lower, require a longer period for fiber growth and development and usually produce less lint often of lower quality.
Fiber Quality Parameter
 Genetics
%
 Environment
%
Staple
 82
 18
Micronaire
 41
 59
Color
 21
 79
Strength
 90
 10


Table 4. The degree of variability in fiber quality parameters as influenced by the genetic makeup of the variety and the environment (weather and management) during the growing season (NCC, 1996).
The relative importance of the fruiting positions oriented from the main stem along a sympodial branch varies, i.e., the first, second and third sympodial positions contribute about 60, 30, and 10 percent of the total seed cotton yield, respectively (Bednarz et al., 2000; Jenkins et al., 1990).  The lint quality tends to also decrease away from the main stem.  The likely production problems occurring during the maturation stage include low temperatures and slow upper-canopy boll development, which can increase boll rot, delay harvesting, reduce the efficacy of defoliants and boll openers, and lower quality lint.
The growth and development of the cotton plant follows a typical sigmoid curve with a relatively slow start during emergence and root growth, followed by an exponential increase in growth rate during canopy formation, flowering, boll development and slowing down during the boll maturation phase (Fig. 7).  Both genotype and environment affect this pattern.  Nevertheless, a general and predictable pattern of growth exists for the cotton plant (Hearn, 1994, Jones and Wells, 1997).
growth-fig-7
Figure 7. The growth and development of the cotton plant follows a typical sigmoid curve (NCC, 1996).
Understanding cotton growth and development is critical in order to implement sound management strategies for maximum yields and profits.  Cotton is a perennial plant with an indeterminate growth habit and has a very dynamic growth response to environment and management.  Site-specific management strategies need to be taken into consideration to optimize yields.  Furthermore, management strategies should be flexible to allow for changing environmental conditions.

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