fibers: cotton and jute (morphology, extraction and uses
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Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 1
Fibers: Cotton and Jute
(Morphology, extraction and uses), BOT-A-CC-4-9-TH
INTRODUCTION:
a. Jute is a natural fiber popularly known as
the "Golden Fiber".
b. Jute fiber comes from the stem of an
herbaceous annual plant Jute Plant
―Corchorus".
c. Jute is the second in the world's production
of textile fibers after cotton
d. India, China, Bangladesh are leading
producers of Jute
e. Jute is almost entirely a market oriented crop
f. Bangladesh is the largest cultivator of raw jute
g. The plant has a height of 8 to 12 feet
STRUCTURE OF FIBER:
Commercial jute varies from yellow to brown to greyish in
color.
The bundle of fibers held together by gummy material; lignin
which plays an important role in structure of plant.
By contrast with the regular lumen of flax, that of jute is
irregular; it becomes narrow in places quite suddenly.
Types of jute:
Jute is a bast fibre obtained from the secondary phloem
of two species of the genus Corchorus belonging to the
family Tiliaceae.
Two species of Corchorus are (a) C capsularis L and
(b) C olitorius L Corchorus capsularis and C olitorius are considered to have originated in
Indo-Burma and Africa respectively.
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 2
Corchorus capsularis L-Jute, white jute; pat or tita-pat. It is a lowland species. Plant is an
annual under- reaching up to a height of 3-6 m. Stem branched or unbranched. Leaves
stipulate, glabrous, 5-13 cm x 582 cm, ovate-oblong. Flowers in extra-axillary cymes in
groups of 2-5 or more, smaller (0.3-0.5 cm in length). Sepals 5. coloured or green, petals 5,
yellow or pale yellow; stamens 20-30; ovary rounded, 5-carpelled, ovules Sialy 10 in each
loculus in two rows, styles 2-4 mm, stigmas 2-3 fid, pubescent. Capsule rounded, 1-1.5 cm in
iameter, wrinkled, rarely smooth, muricate, 5-locular, seeds 7-10 in two rows in each loculus,
without transverse cartitions. Seeds oval, small, chocolate brown.
C olitorius L-Jews mallow or Tossa jute; Koshta or mitha-pat. It is an upland species. Plant is
an annual under-shrub growing up to a height of 4.5 m. Stem branched. Leaves stipulate,
stipules larger than capsularis; gatrous, 7-18 cm x 4-8 cm, oblong. Flowers in extra axillary
cymes in groups of 2-5, about 1 cm in length, larger than capsularis. Sepals 5 or 6, coloured
or green; petals 5 or 6, entire or splitted, yellow; stamens 30-60; ovary Bongated, 5 or 6
carpelled, ovules usually 40 in each loculus in one row; styles 3-5 mm; stigma globular,
entire, pubescent. Capsule long cylindrical. 6-10 cm long, 0.3-0.8 cm in diameter, ridged
lengthwise, 5-6 locular; seeds 40 in single row in each loculus with transverse partition
between each seed. Seeds pyramidal in outline, smaller an capsularis, bluish-green to steel-
grey or even black in colour.
Climate-
Generally warm and humid climate with temperature ranging from 24°C to 35°C and 90%
relative nty favour the growth of jute plants. Untimely rain, continued drought, stagnant water
are harmful but the pant can stand flooding to some extent at later stage of growth.
PRODUCTION AND PROCESSING OF FIBER:
Jute is a rainy season crop, sown from March to May according to rainfall and type of land.
Jute requires a warm and humid climate with temperature between 24c to 37°c. The soil of
good depth, containing salts from annual floods, is best for jute. The stalk diameter of plant
is3\4 inches.
STAGES OF PRODUCTION & PROCESSING:
✓ Cultivation ✓Harvesting ✓ Retting ✓Stripping ✓Washing ✓ Drying ✓Bailing &
Packing ✓ Storage
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 3
Cultivation process:
Sowing of jute starts with the showers in March or April and continues till early June.
Phosphorus, Potash & Nitrogen fertilizers are used for
this crop.
Harvesting Process : Jute is harvested any time between
120 days to 150 days when the flowers have been shed,
early harvesting gives good healthy fibers. The harvested
plants are left in the field for 3 days for the leaves to shed
(means leaves got dried up).
Retting Process : Retting is a process in
which fibers get loosened due to
decomposition of hard cell walls by the
action of bacteria. The bundles are steeped
in water at least 60cm to 90cm depth.
Stripping Process (Fiber Extraction):
Stripping is the process of removing the
fibers from the stalk after the completion of retting. Fibers are removed from the stalk by any
one of the following methods:
1. Single plants are taken and their fibers are taken off.
2. Taken off a handful of stalks, breaking it in a to and fro motion in water.
Washing Process: Extracted fibers are washed in clean water. The dark color of fibers can be
removed by dipping them in tamarind water for 15 to 20 minutes and again washed in clean
water.
Drying Process: The fibers are hung on bamboo railings for sun drying for 2-3 days. After
drying, the fibers are ready to be sold in the
market.
Bailing & Packing Process:
The bailing of jute fiber is done according to
grading system. The fiber is graded into Top,
Middle, B, C and X- Bottoms.
Packing into Kutcha bales about 250 pounds
for use in mills or jute market.
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 4
Properties:
1. Fiber Surface & Appearance: Yellow to brown to dirty grey in color and Natural Silky
Lustrous appearance
2. Tensile Strength: Not stronger than flax because of the irregularities in the thickness of
cell wall.
3. Elongation: Elongation at break = 1.7%
4. Elastic Properties: It is a stiff fiber and not tends to return its original length completely
when the tension is relaxed.
5. Specific Gravity: 1.5
6. Length: 1-4 meters (3-12 feet) Properties
7. Effect of Moisture: Moisture Regain = 13.75% Jute can absorb as much as 23% of water
under humid conditions
8. Effect of Age: High content of non-cellulosic matter makes jute sensitive against chemical
and photochemical attack.
9. Effect of Microorganisms: Jute is more resistant to micro- organism due to protective
effect of lignin.
Advantage:
Great antistatic properties
Low thermal conductivity.
100% Biodegradable; so it is environment friendly fiber like Cotton.
Cheap in market.
Can be widely used in Agriculture Sector, Textile Sector, Woven Sector, Nonwoven
Sector.
Jute Fiber can be blended with Natural and Synthetic fibers.
Disadvantages: -
The crease resistance of Jute is very low.
Drape Property is not good enough.
Create Shade effect and becomes yellowish if sunlight is used.
If Jute is wetted it loses its strength.
End Uses: Jute is cheap and reasonably strong and is available in large quantities. Generally
used in:
● Sacks & Packing Cloth
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 5
● Food Storage
● Backing cloth for carpets
● Curtains & Furnishing fabric
● Used in Geotextiles, technical textiles and textile
● composites Mixed with wool, used in cheap clothing
COTTON FIBER
Introduction:
● Cotton referred to as the "King of fibers" is most
important textile fiber in the world.
● Cotton is a vegetable fiber which surrounds the
seeds of the cotton plant.
● Cotton has been cultivated for more than 5000
years.
● Cotton plant belongs to the
family "GOSSYPIUM".
● The cotton fiber is made up of
countless cellulose molecules.
Cotton is removed mechanically
from the seed bolls by the cotton
ginning. The ginned cotton is
then pressed into bales and sent to the factories to be spun into yarns.
Species of Cotton: There are four commercially-grown species of cotton:
1. Gossypium hirsutum – upland cotton, native to Central America, Mexico
2. Gossypium barbadense – known as extra-long staple cotton, native to tropical South
America
3. Gossypium arboreum – native to India and Pakistan
4. Gossypium herbaceum cotton, native to Southern Africa
Four species of cultivated Gossypium are :
(1) Gossypium arboreum L-This species is diploid (2n-26 chromosomes) and forms the desi
cotton of Inda It is also grown in Arabia and Africa. The staple is coarse, vary short (about
10.5 mm-110.05 mm in length) but strong. This cotton was probably the first to be used
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 6
commercially. Plant is a perennial tree. Leaves palmately lobed, lobes mucronate. Flowers
axillary, large, solitary on jome peduncles; bracteoles 3, large, leafy, cordate. Calyx cupular,
truncate or slightly 5-toothed. Petals 5, connate a base. Stamens numerous, monadelphous
forming a staminal column, anther one-celled. Ovary 5-chambered, S clavate, 5-groved at the
apex, stigmas 5; ovules many in each chamber. Fruit capsule, oblong, pointed. Se free,
covered with white wool overlying a dense green down.
(2) Gossypium herbaceum L-This species is also diploid (2n=26 chromosomes). It is the
chief cotton of and also forms desi cotton. In India, this species has been growing since time
immemorial. It is utilised lo quality fabrics, carpets, blankets etc and for blending with wool;
cottons obtained from this species are gene coarse and short to medium stapled.Plant is an
annual shrub, sub-glabrous or hairy. Leaves cordate, 3-5 or 7-lobed, lobes broadly
accuminate. Flowers yellow with purple centre, rarely yellow or white or purple, petals
spreading, clayx truncate, obovate or cuneate; bracteoles equalling the capsule, not divided
below the middle. Capsule ovate, globose, mucronate, 3-5 valved. Seeds 5-7 in each cell,
ovoid. Cotton white, rarely brownish, overlying a greenish or greyish down.
(3) Gossypium hirsutum L-It is a tetraploid (2n=52 chromosomes) and new world species. It
is a native of America and constitutes American and Cambodia cotton and is commonly
called upland cotton. Upland cotton stitutes the greater part of the cultivated cotton of the
world. The fibres are fine and white, staple length ranges from 6.2 mm to 25.7 mm. This
species is characterised by the following characters. Flowers are white or light yellow and
unspotted. Fruits holls as these are called, are 4 or 5-valved. Seeds are fuzzy all over. Other
characters are like those of G. arboreum.
(4) Gossypium arboreum L var nadam (Watt) Prokh (Syn G barbadense L) -This is also a
new world and tetraploid (2n-52 chromosomes) species. The native home of this species is
probably South America.
Under this Species, there are two distinct types of cotton e.g.,
(a) Sea-island Cotton-Purely cultivated form. Fibres are
fine, light cream coloured, strong, regular in the number
and uniformity of twist and silkier in appearance.
Staples range in length from 38.0 mm to 50.8 mm or
more. Sea-island cotton was introduced in USA. from
West Indies in 1785. In India, another variety under this, known as Andrews having
extra long staple can be cultivated successfully in the costal areas of Kerala and
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 7
Karnataka. This variety is susceptible to large number of pests and diseases and very
sensitive to environmental conditions.
(b) Egyptian Cotton-It is grown mainly in Nile basin of
Egypt, and was introduced from Central America. In
appearance, this plant is very similar to sea-island cotton
and is probabley of hybrid origin. Staples are brown in
colour and somewhat shorter than sea-island cotton,
measuring from 25.7 mm to 26.1 mm. This cotton is used
for hosiery, tyre fabrics and fine dress materials. Plants
are perennial shrubs or tall herbs, branches purplish. Leaves nearly glabrous, cordate,
3-5 lobed; lobes oblong acuminate, bracteoles very large, deeply gashed ; stipules
linear-lanceolate. Flowers are bright yellow with purple spots. Petals convolute,
Ovary ovoid, pitted, 3-5 celled. Fruits or bolls are oval acuminate 3-valved Seeds are
fuzzy only at the ends, black, free or coherent.
Organic Cotton: It is generally understood as cotton grown from non-genetically modified
plants that is ―to be grown without the use of any 100% BRGANIC 100% ORGANIC
synthetic agricultural chemicals such as fertilizers or pesticides
Cultivation of Cotton:
Cotton is essentially a tropical crop, but its cultivation is carried on successfully over many
parts of the world, far removed from the tropics. The limits of cultivation may be said to be
the 40th latitude on both sides of the Equator.
It is grown either at sea level or at moderate elevations not exceeding 3,000 feet. Cultivation
is confined largely to flat open country and rough hilly tracts, where the minimum
temperature does not fall below 70°F.
Higher temperatures are very favourable, and the upper limit may go up even to 105°F in the
picking season. The crop thrives well in moderate rainfall. Rainfall exceeding 35 inches is
supposed to be harmful to the crop. The lower limit for a purely rain-fed crop is 20 inches.
On black cotton soils, hardly any rainfall is needed over most of the growing period provided
good showers have been received before the crop was sown and a satisfactory start has been
made.
Cotton is grown both as a dry crop and as an irrigated crop. If the rainfall is distributed over
both the monsoons, the extraordinary fertility of the black cotton soil allows a wide variety of
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 8
crops to be grown, and also taking of two crops in the year—one in the north-east monsoon
period, and the other in the southwest monsoon period.
On the other hand, if the rainfall is low and is confined to the north-east monsoon period, the
only one crop is grown in the year. There is considerable mixed cropping practice with
cotton. Pulses such as arhar, black-gram and green-gram and other crops such as groundnut
and the castor, into the mixture. The ‘New World’ cottons are, however, grown pure—
whether as dry crops or as irrigated crops.
Cotton Industry:
Several operations are necessary in order to
prepare the raw cotton fibre, as it comes from
the field, for use in the textile industry. In
brief these operations are as follows—
ginning; baling; transporting to the mills;
picking, a process in which a machine
removes any foreign matter and delivers the
cotton in a uniform layer; lapping, an
operation whereby three layers are combined into one; carding, combing, and drawing during
which the short fibres are extracted and the others are straightened and evenly distributed;
and finally twisting the fibres into thread.
Harvest and Yield:
The cotton crop is usually harvested in three or
four pickings, taken at suitable intervals. Picking
is carried out by hand, mostly by women, the
amount of cotton collected ranging from 20 to 50
lb. per day ppr person. Cotton should be picked
only when the bolls are fully mature, fully open
and the floss has puffed up consequent on
exposure to sun. The yield per acre is low in India as compared to yield in other countries
PROCESSING:
Before the raw cotton is spun into a yarn and woven into
cloths, it must pass through a number of processes such
as ginning, baling, grading, marketing, opening, picking,
carding, combing and drawing. For a long time, hand
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 9
separation was the only way to remove the fibres from the seeds. It was quite a tedious
process, but the invention of the cotton gin in 1793 revolutionised the textile industry
● Ginning: After the removal of dirt, boll and leaf fragments and other foreign matter, the
raw cotton is conveyed to the hopper of a gin of either roller or saw type. The former is
mainly used for cotton varieties having a long staple such as Sea-Island and Egyptian cottons,
whereas the latter is employed for the short staple American upland cotton and
Asiatic varieties. The roller gin cleans more slowly than the saw gin but is less injurious to
long valuable fibres.
● Baling: The fibre as it comes from the gin is pressed hydraulically into bales of 500 pounds
(226 kg) which are partially wrapped in jute or hessian covers (baggings), bound with iron
bands called 'ties' and are marketed in this form.
● Picking: Baled cotton is at first broken and then the fibres are passed through a
'scutcher'where they are beaten, shaken and rolled to remove all the foreign matter. The
strands are then separated and delivered in a uniform layer. At the last picking machine, the
cotton is condensed into a form of sheet known as lap'.
● Carding: The remaining lumps of fibres are
further separated into individual fibres on the
carding machine which helps to place the fibres
parallel. It also facilitates the removal of immature
fibres and impurities such as trash and vegetable
matter.
● Combing and drawing or drafting: Combing is a process wherein short fibres are removed,
while drawing involves straightening and aligning of the fibres. It is customary to apply two
drawing operations after carding and two after
combing. The fleecy lap is condensed through a funnel
into a soft untwisted rope or 'sliver'. It is further drawn
out, slightly twisted and wound on spools. In the
spinning process, the cotton is further drawn out and
twisted into a fine yarn of required strength and
firmness. The finished yarn is wound on bobbins or spools and then goes to the weaving
machines.
Fibers: Cotton and Jute
SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 10
Properties of Cotton Fiber
1. Fiber Surface and Color: Lustrous/ Creamy White color
2. Tensile Strength: Tenacity = 3-5 gm/denier Strength = 40, 000, 20,000 lb per square
inch
3. Elongation: Not easily stretch Elongation at Break = 5-10 %
4. Elastic Properties: Rigid/ Less Flexibility At 2% Extension ----- 74% Recovery At 5%
Extension 45% Recovery
5. Specific Gravity: 1.54
6. Effect of Moisture: Standard Humidity = 8.5 % %3D
7. Effect of Heat: Excellent Resistance
8. Effect of Age: Small loss of strength when stored
9. Effect of Sunlight: Gradual loss of strength when exposure to sunlight, major effect by
Ultra-violet light.
10. Effect of Acids: By hot dilute and cold concentrated acids
End Uses of Cotton
1. Poplins, voiles are made by using Cotton.
2. Cotton is used in great quantity as a fabric for
hot weather wear.
3. The absorbency of cotton makes it an excellent
material for household fabrics such as sheets and
towels.
4. Cotton is widely used in making rainwear
fabrics. It can be woven tightly to keep out the driving wind
arid rain, yet the fabric will allow perspiration to escape.
5. Ventile fabrics, for example, are close-woven cotton mat
erials of this sort which are given additional water resistance
by a chemical proofing.
6. It goes into clothing (shirts, T-shirts, trousers, denim, etc.),
undergarments, boots and shoes, carpets and curtains, hats,
etc.
7. Heavy cotton yarns and materials are used for tyre cords and marquees, tarpaulins and
industrial fabrics of all descriptions.
8. Cotton can be blended with other fibres like polyester, rayon to manufacture fabric for
different applications. Household Items - Bed Sheets - Towels Carpets and Curtains Hats
etc.
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