Class 07 || Science || Ch. 03 Fiber To Fabric

Fiber To Fabric.

Q. What do you mean by the clothes?

Ans.  The substances that are used to cover of our outer body are called Cloth. Clothe is our basic needs. It protects us from heat, cold, rain, dust, insects, etc. 

Clothes also make us civilized and smart. 

Clothes are made of cloth, which is also known as fabric. Fabric is made of fiber.

Q. What do you mean by the fibres ?What are main types of the fibres?

Ans. Fibres are very thin, thread-like strands and basic unit of fabrics or cloth. Examples of fibres are cotton, wool, silk, flax, jute, nylon, polyester, polyacrylic. 

The fibres are spun into yarn which can then be woven on a Loom to make a fabric or cloth.

Q. What do you mean by the fibres ?What are main types of the fibres?

Ans. Fibres are very thin, thread-like strands and basic unit of fabrics or cloth.

Fibers are two types – (1) Natural Fibers and (2) Synthatic or Manmade Fibers.

(1) Natural Fibers- The fibers that are obtained from the nature, naturally are called natural fibres. These fibres are obtained from plants and animals; such as jute, cotton, wool, silk, etc.

Natural fibers can be further classified into two types – (1.1) Plant Fiber and (1.2) Animal Fiber.

(1.1) Plant Fiber: Fiber obtained from plants is called Plant Fiber. For example – cotton, jute, flex, etc.

(1.2) Animal Fiber: Fiber obtained from animals is called Animal Fiber. These are the proteins. For example – wool and silk.

(2) Synthatic or  Manmade Fibers- Fibers that are made or synthesized in laboratory are called Synthatic or manmade fiber, such as terylene, terry-cotton, acrylic, etc.

WOOL

Q. What is wool? From where it comes?

Ans. Wool is a natural fibre which comes from fleece of sheep, goat, yak and some other animals. The fine soft hair are called fleece.

Q. How the wool is formed?

Ans. Animals of cold climates bear a thick coat of hair on their body. This thick coat of hair traps a lot of air and keep them warm (as the air is a bad conductor of heat). It remains the warmth of the body from the harsh coldness of the surroundings. For example: Sheep, Goat, Camel, Yak, etc.

Fleece and Wool bearing animals: Sheep, goat, Camel, Yak, etc. bear two types of hair – coarse hair and fine-soft under hair. 

Fine soft hair of the skin is called fleece. Fibres are very thin, thread-like strands and basic unit of fabrics or cloth.

Fiber for wool is obtained from the fleece (hair) of animals called wool bearing animals.

Wool Bearing Animals

Sheep 🐑 

Sheep gives us milk and meat; in addition to wool. But Sheeps are reared mainly to obtain wool in different parts of the world.

Goat 🐐

A special type of wool is obtained from a special goat named Angora so that it is called the Angora Wool. Angora Goats are found in hilly regions, such as Jammu and Kashmir. 

Pashmina wool is obtained from Pashmina Goats. 

Yak wool is obtained commonly in Tibet and Laddakh. 

Alpaca and Llama are other animals that give wool.

Selective breeding and rearing of sheep: Selective breeding is the process to obtain animals or plants having special characteristics. Sheeps are reared by selective breeding to get the wool. 

In India, sheep are generally reared in the hilly sates of Jammu and Kashmir, Himachal Pradesh, Uttaranchal, Arunachal Pradesh and Sikkim, or the plains of Haryana, Punjab, Rajasthan and Gujarat.

Food of sheep: Sheep are herbivores and feed generally on grass and leaves. 

Process to obtain wool from sheep: 

We can obtain the wool from the Sheep by the following steps:

Step 1 

Shearing - The removing of fleece of the sheep along with a thin layer of skin from its body is called shearing. Shearing does not hurt. This is similar to shaving of beards or hair.

In olden days this was done using pair of metal blades. But now-a-days machine is used to cut off the fleece. 

Usually, hair are removed during the hot weather. This enables sheep to survive without their protective coat of hair. 

Shearing is done generally in hot weather so that sheep could survive without their protective coat of hair untill the winter. 

Step -2 

Scouring – The washing of fleece properly to remove dirt and grease, after shearing; is called scouring.

Step- 3 

Sorting – Separating of fleece according to their texture, after scouring is called sorting. It is done in factories.

Step – 4 

Picking of burr –The small fluffy fibres, are called burrs, Burr is the fiber that gives wool. These are picked out from the hair. This process is called Picking of burr.

Step 5 

Dying of wool– Colouring of the natural fleece of woolen fibers in various colours is called Dying of wool. 

Step 6

Spinning – The straightening, combing and rolling fibers to convert into wool yarns is called spinning. This wool yarn is used in knitting sweaters and woolen cloths, i.e. 

SILK

Silk is another important animal fiber. Silk worm spins silk. Silkworm is reared to obtain silk.

History of Silk:

Silk was discovered in China; around 3500 BC. It was used by emperors only. Silk was a famous trade during ancient times. Due to this, the ancient trade routes which linked China to other parts of the world are called ‘Silk Route’. Indus Valley Civilization also  has Proof of use of silk.

Types of Silk: In terms of luster and texture (coarse, smooth, shiny, etc.) silk are of different types. Different types of silk worm moths produce different types of silk; . For example; Mulberry silk, Tassar silk, Mooga silk, Eri silk, Kosa silk, etc. are produced by different types of silk moth. 

Mulberry silk is the most common silk moth.

Rearing of silkworm: Rearing of silkworm is known as SERICULTURE. Silkworms feeds on mulberry leaves so they are reared on mulberry trees.  

Life cycle of silkworm:

Female silk moth → Lays eggs → After about 14 days eggs are hatched into larva (caterpillars  or  silkworms → Grown into Pupa →Weave a net of silk and enclosed itself → Produce liquid protein from its salivary glands moving it’s head in the shape of ‘8’ forming cocoon→ Live in the cocoon for some time → After coming out of cocoon grows into silk moth.

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

Caterpillars or Silkworms – The larvae of silk moth is called caterpillars or silkworms.

Pupa – Larvae grow in size and enter the next stage called pupa.

Cocoon – Completely covered silk caterpillar by silk fibres is known as cocoon. 

Silk Moth to Silk:

Adult female silk moth lays hundreds of eggs which are stored over a clean cloth or paper strips by Silkworms farmers. Larvae cames out from hatched eggs. these Larvae are kept in clean bamboo trays with fresh mulberry leaves. 

Larvae feed for about 20 to 25 days. Now, larvae move into tiny chambers of bamboo and start spinning cocoon by secreting liquid protein from their salivary glands. Finally they enclose themselves in cocoon. Cocoons get hardened because of exposure to air.

Obtaining of silk from cocoon:

First of all, cocoons are boiled and then silk fiber is separated out; using machines. Machine unwinds the silk thread from cocoons. The process by which silk fiber is obtained is called REELING THE SILK.

Silk thread so obtained is woven into different types of cloths, i.e. fiber.

 Fibre to Fabric

NCERT Question and Answer

Q. 1 You must be familiar with the following nursery rhymes

(a) ‘Baa baa black sheep have you any wool’.

(b) ‘Mary had a little lamb. whose fleece was white as snow’.

Answer the following question.

Q. (a) Which parts of the black sheep have wool?

Ans. The skin of black sheep have wool.

Q. (b) What is meant by the fleece of the lamb?

Ans. Fleece means hair of the lamb.

Q. 2 The silkworm is 

(a) caterpillar 

(b) a larva choose the correct option.

(i) a 

(ii) b 

(iii) both ‘a’ and ‘b’ 

(iv) neither ‘a’ nor ‘b’

Ans. (b) both 'a' and 'b'

Q. 3 Which of the following does not yield wool?

(a)Yak.               (b) Camel

(c) Goat.            (d) Woolly dog

Ans. (d) Woolly dog

Q. 4 What is meant by the following terms?

(a) Rearing.        (b) Shearing

(c) Sericulture

Ans.

(a) Rearing: Taking care of animals including feeding, grazing, breeding, etc. for meat, and other useful products.

(b) Shearing –The removal of wool from the sheep is called shearing.

(c) Sericulture - The rearing of silkworm for obtaining silk is known as sericulture.

Q. 5 Give below is sequence of steps in the processing of steps in the processing of wool which are the missing steps? Add them.

Shearing, _________, Sorting, _________, _________.

Ans. Shearing, Scouring,  Sorting,  Colouring,   Spinning.

Q. 6  Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.

Ans.

Q. 7  Out of the following which are the two terms related to silk production.silk production.

a. Sericulture

b. Floriculture

c. Moriculture

d. Apiculture and

e. Silviculture

Hints: (i) Silk production involves cultivation of mulberry leaves andr rearingsilkworms.

 (ii) Scientific name of mulberry is Morus alba

Ans. 

(a) Sericulture and (b) Moriculture are related to silk production.

Q. 8  Match the words of Column I with those given in Column II:

Ans. 1. (e),   2. (c),    3. (b),    4. (a)

Q. 9 - Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.

Ans.

1 (D) - SCOUR

2 (D) - SILK

3 (D) - FIBRE

1 (A) - WOOL

2 (A) - MULBERRY

3 (A) - CATERPILLAR