Class- 07(Science) Chapter - 03 FIBRE TO FABRIC

 

Chapter- 03

Class- 07(Science)

FIBRE TO FABRIC

 

Fibre:- Long, fine, continuous threads or filaments are obtained from plants and animals.

 

Types of fibres:- (1) Animal fibres

                                (2) Plant fibres

 

ANIMAL FIBRES:- These are obtained from animal source.

Ex. Silk and wool

 

Wool:- It comes from sheep, goat, yak and other animals. These wool yielding animals bear hair on their body.

 

>> Hair keeps these animal warm.

>> Wool is derived from these hairy fibres.

   

        The hairy skin of the sheep has two types of fibres that from its fleece.

(1)  The coarse beard hair.

(2) The fine soft under hair close to the skin.

                The fine hair provide the fibres for making wool.

 

Animals that yield wool:- Several breads of sheep are found in different parts of our country.

 

*Wool is common in Tibet and ladakh.

*Mohair is obtained from angora goats.

*Wool is also obtained from goat hair. The under fur of kashmiri goat is soft. It is woven into fine shawls called Pashmina shawls.

*The fur (hair) on the body of camels is also used as wool.

Ex. Lama and alpaca.

 

From fibres to wool:- For obtaining wool, sheep are reared. Their hair is cut and processed into wool.

 

Rearing and breeding of sheep:- Sheep are required in many parts of our country for wool. So many breeds of sheep required in our country for wool.

    Once the reared sheep have developed a thick growth on hair, hair is shaved off for getting wool.

 

Processing fibres into wool :- The wool which is used for knitting sweaters or for weaving shawls is the finished product of a long process.

 

Some Indian breeds of sheep

Name of breed

Quality of wool

State where found

Lohi

Good quality

Rajasthan, Punjab

Rampur bushair

Brown fleece

Uttar Pradesh, Himachal pradesh

Nali

Carpet wool

Rajasthan, Punjab, Haryana

Bakharwal

For woolen shawls

Jammu and Kashmir

Marwari

Coarse wool

Gujarat

Patanwari

For hosiery

Gujarat

 

Shearing:- The fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing.

 

Scouring:- The sheared skin with hair is throughly washed in tanks to remove grease, dust and dirt. This is called scouring.

 

Sorting:- After scouring, sorting is done. The hairy skin is sent to a factory where hair of different texture are separated or sorted.

 

>> The small fluffy fibres called burrs, are picked out from the hair. The fibres are scoured again and dried. This is the wool ready to be drawn into fibres.

>> The fibres can be dyed in various colours, as the natural fleece of sheep and goats is black, brown and white.

>> The fibres are straightened, combed and rolled into yarn.

(1)SHEARING (2)SCOURING        (3)SORTING(4)CLEANING OF BURRS  (5)DYEING(6)ROLLING

   

 

Silk:- It is animal fibres come from silk worms.

 

Sericulture:- The rearing of silkworms for obtaining silk is called sericulture.

 

Life history of silk moth:- The female silk moth lays  eggs from which hatch larve are called caterpillars or silkworms.

                When the caterpillar or silkworm is ready to enter the next stage of its life history called pupa, it first weaves a net to hold its self.

     The caterpillar secret fibre made of a protein which hardness on exposure to air and becomes silk fibre. Soon the caterpillar completely covers its self by silk fibres and turns into pupa. This covering is known as Cocoon.

   The silk yarn (thread) is obtained from the cocoon of the silk moth.

     There is a variety of silk moths which look very different from one another and the silk yarn they yield is different in texture. Thus tassar silk, mooga silk, Kosa silk etc are obtained from cocoons spun by different types of moths. The most common silk moth is the mulberry silk moth.


From cocoon to silk:-  For obtaining silk. moths are reared and their cocoon are collected to get silk threads.

 

Rearing silkworms:- Silkworms are reared at appropriate temperature and humidity to get threads from cocoons.

 

Processing of silk:- A pile of cocoons is used for obtaining silk fibres. The cocoon are kept under the sun or boiled or exposed to steam. The silk fibres separated out.

 

Reeling of silk:- The process of taking out threads or fibres from the cocoon for use as silk is called reeling is done in special machines. Which unwind the threads of silk from the cocoon. Silk fibres are then spun into silk threads, which are weaven into silk cloth by weaver

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