Cotton is derived from the Arabic word for a plant found in conquered lands. It is unknown where cotton originated, but archaeological evidence suggests it grew in Egypt as early as 12,000 BC and India by 3000 BC. Cotton is grown worldwide, especially in areas like America, South America, Egypt, and parts of India. Cotton is widely used in the textile industry due to its versatility and ability to be made into a variety of fabrics. It is comfortable, absorbent, and durable. Various finishing processes have made cotton resistant to stains, wrinkles, shrinkage and other issues.
2. Cotton The word Cotton is derived from the Arabian word ―Quoton‖ or ―Qutun‖ which means a plant found
in conquered lands. The origin of cotton is unknown. Archeological data suggest that cotton grew in Egypt in
12,000 BC and in India are about 3000 BC. cotton, seed-hair fibre of several species of plants of the
genus Gossypium, belonging to the hibiscus, or mallow, family (Malvaceae).
Areas of Production Cotton is grown all over the world. America (Texas, Arizona) South America (Brazil)
Egypt and India. In India cotton grows on black alluvial soils found in Maharashtra and Gujarat. It is also
cultivated in Punjab and Haryana
Cotton is widely used Textile Fiber in Textile Industry. Due to its versatile uses; people feel comfortable to use
Cotton fiber to make fabric. The fibres can be made into a wide variety of fabrics ranging from lightweight
voiles and laces to heavy sailcloths and thick-piled velveteens, suitable for a great variety of wearing apparel,
home furnishings, and industrial uses. Cotton fabrics can be extremely durable and resistant to abrasion. Cotton
accepts many dyes, is usually washable, and can be ironed at relatively high temperatures. It is comfortable to
wear because it absorbs and releases moisture quickly. When warmth is desired, it can be napped, a process
giving the fabric a downy surface. Various finishing processes have been developed to make cotton resistant to
stains, water, and mildew; to increase resistance to wrinkling, thus reducing or eliminating the need for ironing;
and to reduce shrinkage in laundering to not more than 1 percent. Nonwoven cotton, made by fusing or bonding
the fibres together, is useful for making disposable products to be used as towels, polishing cloths, tea bags,
tablecloths, bandages, and disposable uniforms and sheets for hospital and other medical uses.
3.
4. bales the bales are graded according to the color (ranges from brown–gray–off
white), fiber length.
BALES READY FOR SHIPMENT
2.3 Fiber Properties
1. Microscopic Properties
Longitudinal view under the
Microscope
Crossection of the cotton fiber
ribbon like shape
Some twists also appear at irregular
Intervals.
Convolutions
The thickness of the cell wall determines
the maturity of fiber
2. Physical Properties
(a) Luster Low
Low hence wrinkles easily.
They are quite strong as compared to other fibers and
this strength is increased on wetting upto 25%then
when it is dry. Due to this reason less care is required
during laundering
Cotton does not hold moisture so well as wool and
silk do, but it absorb and feels damp much mare
quickly. it absorbs perspiration and gives a feeling of
coolness. It accepts dyes easily
(b) Resiliency
(c) Strength
(d) Moisture Absorption
5.
6. Processing
1.Gathering of cotton pods: Cotton is picked with hands as well as machines from the fields. Hand picked cotton
results in better quality of cotton fabric.
.
HARVESTING OF COTTON FIBER
2.Ginning: After the cotton has been picked, it‘s taken to the
ginning machine. The fiber is now called cotton Lint. This process
separates the seed from the lint. Apart from that it also separates
twigs, leaves and dirt. The seeds are used for the production of oil,
hydrogenated fats, soaps and cosmetics. Cotton mass is then left
behind.
3. Bailing: The cotton mass is then compressed into bales .these are wrapped with
jute sacking and bound with steel bands. Cotton is supplied to mills in
7.
8.
9.
10.
11.
12.
13.
14. Objects Of Blow Room
•Opening - Opening of compressed cotton bales and cotton bales are made into small tufts.
•Cleaning - To eliminate dust, dirt, broken leaf, seed particles, grass and other foreign impurities
from the fibre.
•Blending/mixing - To produce a comparatively good quality cotton fibre by mixing different
types of cotton together.
•Lap forming -
(a) To convert the opened and cleaned fibre into a sheet of particular width and uniform
weight/unit length is called lap.
(b) To give a cylindrical shape to the pre determined lap by winding it in the lap pin and to make
it suitable for the next process carding.
15.
16.
17. Objectives of carding
•To open the tuft of fibers
•To make the fiber parallel & straight
•To remove remaining trash particles
•To remove short fibers
•To remove naps
•To produce a rove like fiber called silver, which is uniform
in per unit length
20. SILK FIBRE
Silk is known as ―queen of Fibers‖, a title well deserved by the virtue of its association with royalty. The
strongest natural protein fibre composed mainly of Fibroin, silk is a shimmering textile known for its satin texture and
famous for being a luxurious fabric.
Silk is a natural protein fiber produced by the larvae of the silk moth. It is said to have been accidentally
discovered in China and produced there for many years till China was discovered thus making the famous ―silk
route‖. Today China produces 54%, India 14% and Japan 11% of the world silk.
.
The history of silk roots in China, where the production of the textile was kept as a secret for over 2,000 years. The
origins of silk dates back to the Chinese neolithic era as the oldest silk example found has been dated to 3630 BC.
Today, the main countries involved in the production of silk are China, India, Uzbekistan, Brazil, Japan, Thailand,
Vietnam and Iran. Despite the small market share of silk in the Global Textile Market (around 0.2%), the production is
spread around 60 countries all over the world.
China is the world’s biggest producer and main global supplier of silk, followed by India.
The global average of silk production accounts for 80,000 tons per year, of which approximately 70% is
produced in China.
21.
22. Flowchart Of Silk Production
Process
Cultivation of Silkworms
↓
Hatching
↓
Moulting
↓
Spinning the cocoon
↓
Sorting Cocoons
↓
Softening the Sericin
↓
Reeling the filament
23. tree. The silk worm spent their entire life in eating these leaves.
Hatching
Eggs of silk worm are warm up for hatching in winter. It is done by spreading the eggs over the trays in the hatchin
shed and chopped leaves of mulberry trees are spread on the perforated paper. For eating the leaves, the worm
climbs through the holes.
Moulting
After 35 days of hatching worm is 10000 times as heavy as it was born and it has become greenish white cater pilla
Now it is ready to start spinning, silk worm built its cocoon to settle down in it.
Spinning The Cocoon
The liquid silk comes from two glands called spinneret in the silkworm head, as the liquid comes out it is hardened
into very fine filaments which are coated by a gummy substance called sericin which comes from other two glands
nearly.
24. Sorting Cocoons
The cocoons are sorted according to color, size, shape, and texture, as all these affect
the final quality of the silk.
Softening The Sericin
The cocoons are put through a series of hot and cold immersions, as the sericin must be
softened to permit the unwinding the filament as one continuous filament.
Reeling The Filament
The process of unwinding the filament from cocoon is called reeling.
25. How to identify artificial silk:
Cost - typically, artificial silk items will cost less. If the item is cheaply priced, then as a general rule the chances are that it is not genuine silk.
Colour - silk usually reflects some light and will be coated, meaning the colour will not look ‘flat’ and will shimmer. If the colouring of the silk looks like a
flat, block colour, then chances are it is not real silk.
Smell - if you want to test whether silk is real, take a few strands of the material and set it on fire. When burning, it will smell like burnt hair - which is a
very strong, unmistakable smell.
Invisible flame - when burnt, silk will also burn with an invisible flame, and the burning will stop as soon as the flame source is removed.
Touch - if you rub a piece of silk between your fingers for a while then the material will become warm. If it stays the same temperature, then it is not
genuine silk.
It’s labelled as satin - satin does not mean silk. Some may get the two confused, but satin products are often far cheaper than silk products.
The ring test - pulling silk through a ring is a traditional way of checking its authenticity. The ring will slide smoothly over real silk, while fake silk will often
bunch or get caught on the ring.
26. Tenacity:
The silk fibres has very good strength due to presence of many hydrogen bonds to be formed in a more regular
pattern. When it comes into contact of water( wetting conditions) , it gets weakened due to hydrolization of a large
numbers of hydrogen bonds present in it by water molecules. Tenacity of silk fibre ranges between 3 to 6 grams/
denier.
Elongation:
Silk fibre shows very good elongation properties. Silk fibre has an elongation at break of 20-25% under standard
conditions. It's elongation at break gets increased upto 33% at 100% R.H.
Elasticity:
Silk is considered to be more plastic than elastic fibre. If the silk material is stretched excessively, the silk polymers
will slide past each other. This happens due to Betaconfiguration present in the silk polymers. A large number of
hydrogen bonds get ruptured due to application of stretching force. Thus the silk behaves like a more plastic nature
than elastic.
Handle:
The silk fibres have slightly stiffness in feel due very crystalline polymer. Surface of the silk feels smooth.
27. Resistance to Abrasion:
Silk fabric possess good abrasion resistance as well as resistance to pilling.
Absorbency:
It has more absorbency than cotton. The moisture regain of silk is 11%. It absorbs moisture more quickly than cotton but it gets
dried fairly quickly too.
Specific gravity:
The specific gravity of silk is 1.25( degummed silk) It is lighter than cotton.
Thermal conductivity:
Silk is more sensitive to heat than wool. The silk fibre starts to burn at 175°c ( begins to fuse)
Electrical conductivity:
The silk is a poor conductor of electricity. it has a tendency to form static charge, when it is handled during different kinds of
processes like weaving etc. This causes difficulties during processing in dry atmosphere.
28. Drape:
Silk fibre sows good flexibility. The silk fabric poses good drapping properties.
CHEMICAL PROPERTIES OF SILK FIBRE:
The chemical properties of silk fibre are given below:
Effect of water
When silk fibre is kept in boiled water for a short period of time, it does not show any type of effect of boiled water.
Silk fibre tends to loss its strength to some extent when it is kept in boiling water for long time. This strength loss
occurs due to hydrolysis action of water. Silk fibre withstands, however, the effect of boiling better than wool.
Effect of acids:
Silk fibre reacts with acids more quickly. Silk fibre is soluble in hot and concentrated sulphuric acid and hydrochloric
acid. It gets yellowish when it comes into contact of Nitric acid. It is slightly affected by diluted organic acids at room
temperature. The concentrated organic acids dissolve the silk fibres.
29. Effect of alkalis:
When silk fibre comes into contact of Alkaline solutions, it begins to swell. It
dissolves completely after some time. It is treated with 16%-18% solution of
sodium hydroxide at low temperature to creat crepe effect blended
fabric having cotton.
Effect of oxidizing agent:
The fibroin present in the silk doesn't get affected badly by hydrogen peroxide
solution. The weight loss occurs when it is treated in hydrogen peroxide
solution. Chlorine solution affects more badly than Hypochlorite. Low
concentration of chlorine solution does damage to fibroin present in the silk.