Cotton:WHAT IS COTTON.DO U KNOW ?

8/9/2019 Cotton:WHAT IS COTTON.DO U KNOW ?

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COTTON is a unicellular, natural fibercomposed of almost pure cellulose.As taken from plants, the fiber is

found in lengths of 3/8 to 2 inches.


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No one knows exactly how old cotton is.Scientists searching caves in Mexico foundbits of cotton bolls and pieces of cotton cloth

that proved to be at least 7,000 years old.The earliest evidence of using cotton is from

India and the date assigned to this fabric is3000 B.C.

There were also excavations of cotton fabricsof comparable age in Southern America.Cotton cultivation first spread from India toEgypt, China and the South Pacific


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Light to dark cream.

SHADESColored cottons alsohave following shades

Tan Greens Blue

Rust


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Each cotton fiber is composed of concentricEach cotton fiber is composed of concentric

layers. The cuticle layer on the fiber itself islayers. The cuticle layer on the fiber itself is

separable from the fiber and consists of waxseparable from the fiber and consists of waxand pectin materials.and pectin materials.

Primary WallPrimary Wall

Secondary WallSecondary WallLumenLumen


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The most peripheral layer of the fiberComposed of cellulosic crystalline fibrils


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Consists of three distinct layers All three layers of the secondary wall

include closely packed parallel fibrils with

spiral winding of 25-35

o

. Represent the majority of cellulose withinthe fiber


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The innermost part of cotton fiber Composed of the remains of the cell

contents Before boll opening, the lumen is filled with

liquid containing the cell nucleus andprotoplasm. The twists and convolutions ofthe dried fiber are due to the removal ofthis liquid. The cross section of the fiber is

bean-shaped, swelling almost round whenmoisture absorption takes place.


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COTTON

Cellulose 80-90%

Water 6-8%

Waxes and fats 0.5 - 1%

Proteins 0 - 1.5%

Hemicelluloses 4 - 6%

Ash 1 - 1.8%


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Comfortable Soft handGood absorbencyColor retention

Prints wellMachine-washableDry-cleanableGood strength

Drapes wellEasy to handle and sew


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PROCESS GINNING

CULTIVATE

WEAVE SPIN

END

USE


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LTIV

ATION

RE

QUIRE

ME

NTS

A long growing seasonA long growing season

Plenty of sunshinePlenty of sunshine

Water during the period of growthWater during the period of growth

Dry weather for harvestDry weather for harvest

In general, these conditions are metIn general, these conditions are met

within tropical and warm subtropicalwithin tropical and warm subtropical

latitudes in the northern andlatitudes in the northern and

southern hemispheressouthern hemispheres..


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Planting time varies from the beginning ofFebruary to the beginning of June in thedifferent regions of world.

A number of methods, chemical and

mechanical, have been used to controlWEEDS and GRASS, including intensiveSPRAYING of herbicide before and afterplanting.

The cultivator, rotary hoe, and flamecultivator are also used to destroy weeds.


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Now harvested MECHANICALLY with spindle-type pickers or strippers.

PICKERS are used extensively in irrigatedlands. The picker has vertical drumsequipped with wire spindles that engageand pull the cotton from open bolls.

All cotton is stored in modules, which look

like giant loaves of bread.


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Modern gins place modules in front ofmachines called MODULE FEEDERS.

It break the modules apart and feed theseed cotton into the gin.

Some gins use powerful

pipes to suck the cotton

into the gin building.


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Once in the cotton gin, the seed cottonmoves through dryers and through cleaningmachines.

It remove the gin waste such as BursDirt

Stems

Leaf Material.


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Then it goes to the GIN STAND wherecircular SAWS with small, sharp teeth pluckthe fiber from the seed.

From the gin, fiber and seed go differentways.

The ginned fiber, now called LINT.


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FIBER LENGTH

LENGTH UNIFORMITY

FIBER STRENGTH

MICRONAIRECOLOR


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Fiber length is described as The averagelength of the longer one-half of the fibers(upper half mean length). This measure istaken by scanning a "beard " of parallelfibers through a sensing region.


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Length uniformity or uniformity ratio isdetermined as A ratio between the meanlength and the upper half mean length ofthe fibers and is expressed as a

percentage.

Low uniformity index shows that there might be ahigh content of short fibers, which lowers the quality

of the future textile product


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Fiber strength is measured in grams perdenier. It is determined as the forcenecessary to break the beard of fibers,clamped in two sets of jaws.

The breaking strength of cotton is about3.0~4.9 g/denier.

The breaking elongation is about 8~10%.


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Micronaire measurements reflect fiber fineness and

maturity. A constant mass (2.34 grams) of cotton fibers is

compressed into a space of known volume and airpermeability measurements of this compressed

sample are taken. These, when converted toappropriate number, denote Micronaire values.

COTTON RANGECOTTON RANGE MICRONAIRE READINGMICRONAIRE READING

PremiumPremium 3.7-4.23.7-4.2

Base RangeBase Range 4.3-4.94.3-4.9

Discount RangeDiscount Range >5.0>5.0


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The color of cotton samples is determined from twoparameters: Degree of reflectance (Rd)Yellowness (+b)

The color of the fibers is affected by climatic

conditions, impact of insects and fungi, type ofsoil, storage conditions etc.

There is five recognized groups of color:

White

GraySpottedTingedYellow stained


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SWELLINGATTACK OF ACIDS & BASES

OXIDATION & HYDROLYSIS


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Cotton swells in a HIGH HUMIDITYenvironment, in WATER and in concentratedsolutions of certain ACIDS, SALTS andBASES. The swelling effect is usually

attributed to the sorption of highly hydratedions. and the moisture absorption is 7~8%

The moisture regain for cotton is about 7.1~8.5%The moisture regain for cotton is about 7.1~8.5%

Moisture absorption for cotton is 7~8%Moisture absorption for cotton is 7~8%


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Cotton is attacked by HOT DILUTE or COLDCONCENTRATED ACID solutions. Acidhydrolysis of cellulose produces hydro-celluloses. Cold weak acids do not affect it.

The fibers show excellent RESISTANCE TOALKALIS. There are a few other SOLVENTS that will

DISSOLVE COTTON completely.

DO U KNOW!DO U KNOW! Copper complex of cupramoniumCopper complex of cupramonium

hydroxide and cupriethylene diamine (Schweitzer'shydroxide and cupriethylene diamine (Schweitzer's

reagent) dissolve cotton completely.reagent) dissolve cotton completely.


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Cotton DEGRADATION is usually attributedto oxidation, hydrolysis or both. Oxidation ofcellulose can lead to two types of so-calledoxy-cellulose, depending on the

environment, in which the oxidation takesplace.

OXIDATION & HYDROLYSISOXIDATION & HYDROLYSIS


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Cotton fibers show DOUBLE REFRACTIONwhen observed in polarized light. Eventhough various effects can be observed.

Second orderYELLOW and second orderBLUE is characteristic colors of cellulosicfibers. A typical birefringence value asshown in the table of physical properties, is

0.047.

OPTICAL PROPERTYOPTICAL PROPERTY

A typicalA typical Birefringence valueBirefringence value as shown in the table ofas shown in the table of

physical properties, isphysical properties, is 0.0470.047..


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Shirts

Dresses Children wear Active wear Blouses Separates Swimwear

Suits

Jackets Skirts Pants Sweaters Hosiery Neckwear


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Curtains Draperies Bedspreads Comforters

Throws SheetsTowelsTable Cloths

Table Mats Napkins


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Swabs Puffs Wipes Filters Weddings

Personal care products Diapers Feminine Hygiene

products

Semi-durable Segments Bedding Household furnishing Pillow fillers


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0

1

2

3

4

5

6

US

INDI

A

PAKISTA

N

CHIN

A

PRODUCTION IN

MILLION TONS

CONSUMPTION IN

MILLION TONS


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New instrumentation to measure cotton

contamination. Cotton linters to replace the traditional 100%wood pulp fibers for producing absorbentcores for disposable diapers and famine pads.

New quality measurements of small sample

cotton are being developed. Cotton is being blended with kenaf fibers to

improve the softness and hand. Buckeye Technologies has developed 100%

natural cotton for tampon manufacture. Clustering analysis is developed for cotton

trash classification. New method to improve the dyeability of

cotton with reactive dyes.


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Cotton:WHAT IS COTTON.DO U KNOW ?