COTTON is a unicellular, natural fiber
composed of almost pure cellulose.
As taken from plants, the fiber is
found in lengths of 3/8 to 2 inches.
cotton is an important cash crop in more than 80
the major producers in the world are:
in 2007 worldwide, 113 million bales (480 lbs/bale)
Light to dark cream.
Colored cottons also
have following shades
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 wax
and pectin materials.and pectin materials.
•Primary WallPrimary Wall
•Secondary WallSecondary Wall
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..
Modern gins place modules in front of
machines called MODULE FEEDERS.
It break the modules apart and “feed”
the seed cotton into the gin.
Some gins use powerful
pipes to suck the cotton
into the gin building.
Once in the cotton gin, the seed cotton
moves through dryers and through
It remove the gin waste such as
Fiber length is described as “The
average length of the longer one-half
of the fibers (upper half mean
Fiber strength is measured in grams per
denier. It is determined as the force
necessary to break the beard of fibers,
clamped in two sets of jaws.
The breaking strength of cotton is about
The breaking elongation is about 8~10%.
Micronaire measurements reflect fiber fineness and
A constant mass (2.34 grams) of cotton fibers is
compressed into a space of known volume and air
permeability measurements of this compressed
sample are taken. These, when converted to
appropriate number, denote Micronaire values.
COTTON RANGECOTTON RANGE MICRONAIRE READINGMICRONAIRE READING
Base RangeBase Range 4.3-4.94.3-4.9
Discount RangeDiscount Range >5.0>5.0
The color of cotton samples is determined from two
Degree of reflectance (Rd)
The color of the fibers is affected by climatic conditions,
impact of insects and fungi, type of soil, storage
There is five recognized groups of color:
Cotton swells in a HIGH HUMIDITY
environment, in WATER and in
concentrated solutions of certain ACIDS,
SALTS and BASES. The swelling effect is
usually attributed to the sorption of highly
hydrated ions. 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%
ATTACK OF ACIDS AND BASES
Cotton is attacked by HOT DILUTE or
COLD CONCENTRATED ACID solutions.
Acid hydrolysis of cellulose produces
hydro-celluloses. Cold weak acids do not
The fibers show excellent RESISTANCE
There are a few other SOLVENTS that will
DISSOLVE COTTON completely.
identification of cotton
microscopic identification of cotton is relatively easy—
convolutions are easily seen along the fiber
burn tests verify cellulose
fiber length helps identify content
cotton is soluble is sulfuric acid
properties of cotton—care
cotton can be washed with strong detergents and
requires no special care during washing and drying
white cottons can be washed in hot water—dyed
cottons retain their color better if washed in warm water
cotton releases most soils readily but soil-resistant finishes
are desirable for some interior & apparel uses
excessive bleaching weakens cellulosic fibers
cotton fabrics respond best to steam pressing or ironing
while damp—can be ironed safely at high temperatures
properties of cotton—care
cotton draperies should be dry-cleaned
cotton upholstery may be steam-cleaned with caution
cottons should be stored clean and dry
cotton is harmed by acids—fruit & fruit juice stains
should be treated promptly
cotton oxidizes in sunlight which causes yellowing and
degradation—some dyes are especially sensitive
Wide range of wearing