Fibers: Cotton and Jute (Morphology, extraction and uses

Fibers: Cotton and Jute

SAJAL BERA, DEPARTMENT OF BOTANY, RAMSADAY COLLEGE Page 1


(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.



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



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.



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



● 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



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



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



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



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.



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.

Documents

Fibers: Cotton and Jute (Morphology, extraction and uses