Fibre To Fabric

Humans rear silkworms for obtaining silk. Silkworms spin the “silk fibres”. This practice of rearing of silkworms for obtaining silk is called sericulture. The silk fibres obtained from silkworm are then used for weaving silk clothes.

Moth is not a type of silk but it is a type of insect which is responsible for the production of silk fibre. Cocoon is formed at one of the life stages of silk moth through which we obtain silk fibres. Mulberry, Tassar, Mooga are different types of silk which are obtained from cocoons spun by different types of moths.

Wool fibres are obtained from sheep by removal of hairs (fleece). This process is called shearing. Machines similar to those used by barbers are used. So sheep are not at all harmed during making of woollen shawls but silk scarf, animal fur cap and leather jacket are obtained by killing animals.

•Cocoon is formed at one of the life stages of silk moth. Caterpillar/ silkworm completely covers itself by silk. This covering is known as cocoon. Silk fibre is thus obtained from cocoon.

•Wool fibre is obtained from fleece of sheep.

•Cotton fibre is obtained from cotton ball.

•Jute fibre is obtained from shiny jute stalk.

Moth is a type of insect which is responsible for production of silk fibre and not wool fibre. Wool can be obtained from rest of the given options by shearing. Shearing is the removal of hairs to obtain wool fibres.

The process of selecting parents for obtaining special characters in their offspring (next generation) is termed as “selective breeding”. This can be understood with the help of following example:

Fine hairs of sheep are desired for making wool. Some breeds of sheep possess only fine hairs. Their parents are specially chosen to give birth to sheep which have only fine hairs.

The process of shearing involves the removal of fleece (hairs). These fibres are then further processed to obtain wool fibres.

After shearing, washing of sheep fibre takes place followed by separating hair of different textures (called sorting). Last stage in obtaining wool fibre is rolling of sheep fibre into yarn.

The term “sericulture” means “silk farming”. The practice of rearing of silkworms for obtaining silk is called sericulture. Silkworm completely covers itself by silk fibre. This covering is known as cocoon which is further processed to obtain silk.

When cocoons are boiled/ exposed to steam, the silk fibres separate out. The process of taking out threads from the cocoon for use as silk is called “reeling of silk”. Silk fibres thus obtained are then spun into silk threads which are woven into silk clothes later.

The caterpillar/ silkworm secretes fibre made of a protein which get hardened on being exposed to air and become silk fibre. Silkworm completely covers itself by silk fibres and this covering is called cocoon which is further processed to obtain silk fibres.

(a) Silk and wool fibres are obtained from animals.

Fibres are obtained from plants as well as animals. The example of fibre obtained from plants is cotton fibre (obtained from cotton plants). The examples of fibres obtained from animals are silk and wool.

•Silk fibre is obtained from silk moth.

•Wool fibre is obtained from fleece (hair) of sheep/yak/goat.

(b) Silk fibres come from cocoon of silk worm.

Silk fibres come from the cocoon of silkworms. Silkworm completely covers itself by silk fibres. This covering is known as cocoon. When cocoons are boiled/ exposed to steam, the silk fibres separate out.

(c) Wool yielding animals bear fleece (hair) on their body.

Wool comes from varieties of animals such as sheep, yak and goat. These wool-yielding animals bear hair on their bodies. These hairs keep these animals warm in cold weather. These hairs are removed for obtaining wool fibre.

(d) Hair trap a lot of air, which is a poor conductor of heat.

Animals have thick coat of hairs. These hairs keep them warm. This is possible because thick hairs trap a lot of air in them. Air is a poor conductor of heat i.e. air prevents the loss of heat from their bodies.

(a) True

Silk moth is an insect which is responsible for yielding silk fibre. Silk moths lay eggs, from which larvae come out. These are called as caterpillars or silkworms. Thus we can say that silkworms are the caterpillars of silk moth.

(b) False

Wool fibre is obtained from varieties of animals such as sheep, yak, goats and camel. But in India generally sheep are reared for obtaining wool. Goat rearing for wool is also practices in India on a smaller scale but camel rearing for wool is very rare.

(c) False

Humans rear silkworms for obtaining silk. This practice of silkworms for obtaining silk is called “sericulture” and not silviculture. Silkworms spin the “silk fibres”. These fibres are then used for weaving silk clothes.

(d) True

Scouring is process of cleaning the removed hairs by washing into tanks for removing grease and dirt. After scouring, sorting is done which involves the separation of hairs of different textures.

(e) False

Wool fibres can be obtained from varieties of animals such as sheep, yak, goat and camels. Thus yak hairs can also be used to make woollen fabric. Thus the above statement is false.

Animals have thick coat of hairs. These hairs help certain animals in keeping their bodies warm such as yak, sheep etc. Hairs of these animals trap a lot of air in them. Air is a poor conductor of heat i.e. it prevents the loss of heat from their bodies to cold surroundings. In this way hair of certain animals help in keeping their bodies warm.

Correct match of items of column I with column II is as follows:

(a) Yaks are found in Tibet and Ladakh and thus yak wool is produced in these regions.

(b) Angora goats are found in Jammu and Kashmir.

(c) Mulberry leaves are used to feed silkworms.

(d) Scouring is the process of cleaning of the sheared (removed) hairs by washing into tanks to remove grease and dirt.

The correct sequence of steps to obtain wool from fleece (hair) is as follows:

ShearingScouringSortingPicking out the blurrsDyeing in various colours

1) Shearing: Removal of fleece/ hair from sheep is known as shearing.

2) Scouring: Removed hairs are then cleaned by washing into tanks to remove grease dirt and grease.

3) Sorting: The process of separating hairs of different textures.

4) Picking out the blurrs: Blurrs are small fluffy fibres which are picked out from the hairs. These fibres are again cleaned and dried.

5) Dyeing: The fibres are then dyed into varieties of colours because the wool fibres originally obtained are black, brown and white in colours.

(a) SERICULTURE

Humans rear silkworms for obtaining silk. Silkworms spin the “silk fibres”. This practice of rearing of silkworms for obtaining silk is called sericulture. These silk fibres are then used for weaving silk clothes.

(b) SILKWORM

Silk moth lays eggs from which larvae come out. These are called caterpillars/ silkworms. They completely cover themselves with silk fibre. This covering is called cocoon from which silk fibre is obtained.

(c) MULBERRY

Mulberry tree leaves are used to feed silkworms. Silkworms eat day and night and increase in size. After eating mulberry leaves for 25 to 30 days, they start to spin cocoons.

(d) REELING

When cocoons are boiled/ exposed to steam, the silk fibres separate out. The process of taking out threads from the cocoon for use as silk is called “reeling of silk”. Silk fibres thus obtained are then spun into silk threads which are woven into silk clothes later.

(1) In the innermost ring, the letters Y, A, K form the name of wool-yielding animal. Thus the name of animal is YAK.

(2) In the middle ring, the letters C, A, M, E, L form the name of wool yielding animal. Thus the name of animal is CAMEL.

(3) In the outermost ring, the letters S, H, E, E, P form the name of wool yielding animal. Thus the name of animal is SHEEP.

(a) Eggs of silk moth on mulberry leaf: Silk moth has laid eggs on mulberry leaf from which caterpillar/ silkworm will come out and will feed on mulberry leaf.

(b) Silkworm: Silk moth lays eggs from which larvae come out. These are called caterpillars/ silkworms.

(c) Cocoon: silkworms completely cover themselves with silk fibre. This covering is called cocoon from which silk fibre is obtained.

(d) Cocoon with developing moth: Moth starts developing inside cocoon. When cocoon is boiled/ exposed to steam to separate silk fibres, the moths present inside are killed.

The whole process of production of silk can be described by arranging the given steps in correct order.

(1) Female silk moths lay eggs.

(2) Eggs are warmed to a suitable temperature for the larvae to hatch from eggs.

(3) The larvae/caterpillars or silkworms are kept in clean trays along with freshly chopped mulberry leaves (silkworms feed on mulberry leaves).

(4) After 25 to 30 days, the caterpillars stop eating and start spinning cocoons (caterpillars cover themselves into silk fibre and these coverings are called cocoons).

(5) Cocoons are kept under the sun or boiled in water.

(6) Fibers are taken out from the cocoon (this process is called reeling)

Correct match Column I and Column II items is as follows:

(1) Pashmina shawls are made from the wool obtained from the hairs of Kashmiri goats.

(2) Carpets are made from the wool obtained from camel hairs.

(3) Angora wool is quite soft and used to make soft baby blankets.

(4) Wool obtained from hair of sheep is used to make woollen sweaters.

The (a) female silk moth lays (b) eggs, from which hatch (c) larvae called (d) caterpillars or (e) silkworms. They grow in size and when the caterpillar is ready to enter the next stage of its life history called (f) pupa, it first weaves a covering to hold itself, which is known as (g) cocoon.

Firstly the female adult silk moth lays eggs from which larvae come out.

These larvae are called caterpillars or silkworms.

These silkworms feed on mulberry leaves and start to grow in size.

The next stage of life of a silkworm is called pupa.

Before entering into next stage, caterpillar covers itself into silk fibre. This covering is called cocoon.

The thread which burnt with the smell of burning hair is from pure silk saree. The reason for this conclusion is that both hair and silk are protein fibres. Thus silk fibre on burning gives the same smell as a hair strand.

The thread which burnt with the smell of burning paper is from pure cotton saree. The reason for this conclusion is that both cotton and paper are obtained from plants. Both are made up of carbohydrates and thus on burning gives same smell.

A fibre is a thin strand of a material. One can easily break a fibre because a single fibre is too weak. Fibres can be spun into yarn and made into fabric. When a large number of fibres are weaved together, fabric is made. Tearing apart a fabric is very difficult. Thus we can say that uniting large number of fibres provides them strength. Therefore the phrase “Unity is Strength” fits correctly to the making of fabric from fibre.

The various steps for processing fibres into wool are as follows:

(1) Shearing: Firstly the fleece (hair) of sheep is removed. This process is called shearing.

(2) Scouring: The sheared (removed) hairs are then cleaned by washing into tanks to remove grease and dirt. This process is called scouring.

(3) Sorting: Cleaned hairs are then sent to factory here separation of different textures of hairs takes place. This process is called sorting.

(4) Picking out blurrs: Blurrs are the small fluffy fibres which are picked out from hairs. These fibres are again cleaned and dried.

(5) Dyeing: The fibres are then dyed into various colours.

(6) Rolling into yarn: The fibres are straightened, combed and then finally rolled into yarn (thread).

The life history of silk moth can be described and represented as follows:

(1) Firstly the female silk moth lays eggs from which larvae come out.

(2) These larvae are known as caterpillars or silkworms.

(3) They start growing in size by feeding on mulberry leaves.

(4) The next stage of its life history is called pupa but before entering this stage caterpillar covers itself into silk fibre. This covering is called cocoon.

(5) Inside cocoon, the pupa develops into a moth and comes out as an adult silk moth.