Cotton Fibers

Grown in humid and hot area April-May-North india June-july-Central India July-august-southern india

Properties of cotton Composition Structure of cotton Lenth,diameter Color

Compostion Made of carbon,hydrogen,oxygen 90% cellulosic,6% moisture Wax (makes it water proof)

The cotton polymer is a linear, cellulose polymer. The repeating unit in the cotton polymer is cellobiose which consists of two glucose units.

Compostion Made of carbon,hydrogen,oxygen Its polymer system is about 65-70%

crystalline and 35-30% amorphous

Structure of cotton Cross-Section is Oval or Kidney shaped Cuticle- Very-outside skin of cotton fiber.It is composed of waxy Layer.

Primary wall- immediately underneath the cuticle ,is about 200nm thick .it is composed of very fine fibrils.

Structure of cotton Lumen Secondary wall which forms the bulk of

the fiber .and concentration of cellulosic fibrils.

Lumen –Hollow canal ,running the length of fiber called lumen .Made of cell sap which composed of cell waste products

when sap evaporated ,its constituents remained behind contribute to the colour of cotton fiber

Color

Creamy –white

Length /DiameterDiameter- 0.00046 to 0.001”

1. Short-staple cotton: Short, coarse fibres that are 3/8 to 3/4 inches in length. Primarily produced in India and eastern Asia.2. Intermediate-staple cotton: Intermediate length and coarseness. 7/8 to 1.25 inches in length. Produced in American Upland.3Long-staple cotton: Highest quality. 1.31 to 1.5 inches in length Used to make softer, stronger, smoother and more luxurious fabrics. Produced in ,Egypt

Physical Properties Tenacity(Strength)- Cotton have about

70% crystalline region so posses good strength

When wet gains strength ,because of temporary improvement in polymer alignment in amorphous regions

Elastic nature–Relatively inelastic due to its crystalline polymer system and for this reason cotton textiles wrinkle and crease readily

Physical Properties Absorbency- Cotton fiber is very aborbant Because of OH

groups in its polymers ,these attracts water molecules So No static buildup Thermal Property- Cotton fibers have the ability to conduct

heat energy thus they can withstand hot ironing temperature Lustre- very low because of kidney shape

Loose strength in sunlight Not destroyed by cloth mouth but destroy by mildew under

moist conditions

Chemical Properties Effect of acids- weakened and

destroyed by strong acids Effect of Alkali- Cotton fibers are

resistant to alkalis and are relatively unaffected by normal laundering.

Mercerization- when 18% alkali solution of sodium hydroxide is absored by cotton ,strength increase and lustre also

Chemical Properties Effect of bleaches- The most common

bleaches used on cotton textile materials are sodium hypochlorite and sodium per borate.

Sodium hypochlorite bleaches cotton textile materials at prevailing room temperature. However, bleaching with sodium per borate is more effective when the laundry solution exceeds 50°C in temperature.

Physical properties Soft handle Strength Poor Elasticity Good Drape Good Conductor of heat-so easy to wear

in summer & winter Good Absorbency

Processing of cotton 1. Growing - cotton grows on bushes 3-

4 feet height, the blossoms or flowers appears, falls off and the boll begins its growth, inside the boll are the seeds from which the cotton fibers grow. This is also called seed hair. When ball is ripe, it splits open and the fluffy white cotton stands out from the boll.

Harvesting-The cotton is picked up with the help of machine or by hand. Cotton gets discolored and dirty if it is kept on plant for longer duration.

2.Ginning- in this process seeds are removed and fibers are pressed into bales. This process is carried out by a machine. Seeds are used for the production of oil, soaps and cosmetics.

Ginning3. Bailing- cotton is compressed or pressed into bales.

These are wrapped with jute cocking and cotton is then supplied to mills in bales.

Spinning Spinning is the process where fiber is

converted into yarns Yarns are a grouping of fibers twisted

together to form a continuous strand

Flow chart of spinning process

The Blowroom It involes a set of machinery which

opens and cleans the raw cotton. Basic Operations are Opening and Mixing cleaning Dust removal Blending

The Blow room

Cleaning /Dust Removal It is the process to remove the

impurities.It depends on raw material Suction units which removes the dust Dust is removed by air suction The efficiency depends not only on the

machine but also on the size of flocks

Dust Removal Suction units which removes the dust Dust is removed by air suction The efficiency depends not only on the

machine but also on the size of flocks

Blending/Mixing It is the process which collects the

bunches of fibers arriving sequentially from individual bales and mix them thoroughly

Carding Function Opening Cleaning

Input-LapOutput-Card sliver

Draw Frame Function To parallel the

fibers Drafting

Input-Card sliver Output-draw frame sliver

Combing Function To remove short

fibers To parallel fibers

Ring Frame Function Twisting Drafting

Input-RovingOutput-yarn

Speed/roving frame Prepare package

for Ring frame To impart twist

Input-D/F sliver Output-Roving