Animal fibre

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Animal Fibre lesson prescribed by APSCERT & TGSCERT for Class VII Science. PPT prepared by M Padma Lalitha Sharada of GHS Malakpet.

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ANIMAL FIBRE[Part-1]

By M PADMA LALITHA SHARADA GHS Malakpet

For Class VII General Science

APSCERT & TGSCERT

New syllabus

Under guidance

Of

Smt. C.B. NIRMALA

Rtd. Dy. E.O.

Nampally Mandal

Hyderabad

The fibres derived from plants like cotton and jute that are made into fabric.

We get fibres from plants and animals.

Cotton, Jute, Gongoora, Coconut plant fibers are useful to make different kinds of fabrics.

In the same way we get fibres of silk and wool from animals like silk worms and sheep, goat, camel, yak etc.

Let us find out about these animal fibres.

Story of silk:

Moth to egg

we call the eggs of silk moth seeds.

Silk moth is like butterfly. Those moths will be kept in grill mesh boxes in separate rooms.

People call them as ‘Chilakalu’. Another name of these moths is ‘Bombyx Mori’.

At the time of laying eggs people arrange white cloth pieces or paper. Moths lay hundreds of eggs on them.

A female moth lays around 500 eggs in one go and dies. Those eggs are very small in size.

People generally allow these eggs to hatch in special chambers usually over mats, on beds of chopped mulberry leaves to get small worms.

Sometimes silk moths are also sold. People buy these silk moths to produce eggs. These centers are called ‘Grinages’.

There is a big seed growing centre at Horsely Hills in Chittoor district.

Egg to cocoon

Here large trays with leaves and larva feeding on them could be seen. Some trays had white and yellowish egg like structures!

The whole process of obtaining silk starting from silk moth is called sericulture.

Tiny white coloured silk worms (caterpillars) will be placed in trays. People chop Mulberry leaves into small pieces to feed them.

These worms eat leaves day and night. They need good hygienic conditions and proper light to grow.

When they grow bigger in size, people transfer the worms into big sized cane frames called “Chandrikalu”

After 30-35 days the caterpillar stops eating and settles at a particular place. It weaves a net to hold itself.

Caterpillar moves its mouth from side to side and secretes fibre-like substance. When it is exposed to air and heat it becomes strong.

The net is woven completely to cover the body of the catterpillar. This seems to be a closed sack. This is called ‘Pattukayalu’ (Cocoon).

The larva of silk worm undergoes changes in the cocoon to change into a moth. After 2-3 weeks young moths come out from the cocoons and fly away.

So we have to be very careful. Within 2-3 days of formation of cocoon, people start removing them from the tray.

People kill the larvae inside by a process called stiffling by putting a lot of these in a steam oven for 10 to 15 minutes.

The cocoons have to be stiffled to kill the larva inside as otherwise, it will cut its way out after growing into a moth and spoil the cocoon.

We will not be able to get a continuous thread of silk from such a cocoon. Thus we won’t be able to obtain quality fibre for fabric!

Stiffling helps us to store the cocoons for a long time. This process is usually done in a reeling centres.

These cocoons are kept in sealed bags and sold at the cocoon market. If not stiffled, people sell them off within a week.

Apart from Mulberry , Tasar silk (Desali Pattu) is produced in our State.

Some species of silk moths that lay eggs on termanalia (oak) plantation produce tasar silk.

Mostly tribal people rear these kind of cocoons. This silk plantation is mainly concentrated in Karimnagar, Adilabad, Warangal, Khammam and coastal regions of East Godavari and Visakhapatnam.

Cocoon to fibre – Process of Reeling; fibre to yarn

Locating ends of thread of cocoon

Located ends reeled onto reels

Caterpillar of silkworm spins fiber which is mainly made up of two types of protein (sirisine and fibroin) and is very strong.

The cocoons have to be boiled to loosen the fibre to be able to reel it.

Obtaining silk fibre from cocoon is called reeling. It is done with special machines called reelers and twisters.

The silk fibre is carefully collected from the cocoon and nearly 3 to 18 of such threads are wound together to make yarn from it which is reeled.

This yarn is cleaned, bleached and coloured.

The yarn is ready to be woven into a variety of designed fabrics, on looms. We can see reeling centres at Nandikotkur, Hyderabad, Karimnagar etc.

Warp of sari being prepared.

Reeling to weaving

Pochampally is silk city of our state. People weave silk fabric by using silk yarn on handlooms.

For them , weaving is a traditional occupation. They get silk yarn from reeling centres to weave a variety of sarees.

Pochampally pattu and Dharmavaram are famous types produced by our state.

Pochampally – Silk City

Pochampally pattu is also called ‘tie and die or Jamdani’.

Dharmavaram is famous for its wide border and rich buta or dots.

A Jamdani sari on loom. Weft being woven over warp.

Banaras, Kanchipuram, Dharmavaram, Narayanpet, Kothakota, Pochampally are all types of silk fabrics. They get their names from the places where they are made.

Banaras Kanchipuram

Narayanpet

Kothakota

There are some more varieties of silks such as tasar silk, mooga silk, kosa silk, eri silk and so on.

tasar silk mooga silk

kosa silk eri silk

Some chemicals add strength to silk fibres.

Silk is used to make other products as well like satin and crepe.

satin crepe

We have both handlooms and power looms to weave silk.

The thread we get from the average cocoon ranges from about 1,000 to 3,000 feet, and about 2,000 to 3,000 cocoons are required to make 500 gm of silk. That is about 5,000,000 feet or more than 1,000 miles!

People involved in the process suffer from skin as well as respiratory problems due to continuous handling of the silk worm and the silk fibres.

THANK YOU Smt. Nirmala

Madam

Sharada

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