by Dilip Kumar Chandra PGT Biotechnology JNV Raipur CG

2. • Fabrics are made up of yarns and yarns
are further made up of fibres .
• Fibres such as cotton,jute,silk and wool
are obtained from plants and animals.
These are called natural fires

5. silk

13. A skein of super yak

15. Rearing and breeding of sheep
• Sheep's are reared in many parts of our
country for wool. Sheep are herbivores
and prefer grass and leaves. Rearers
also feed them on mixtures of pulses, corn
jowar, oil cakes and minerals.
• Once the reared sheep have
developed a thick growth of hair,hair is cut
off for getting wool.

16. Some Indian breeds of sheep
s.no Name of
breed
Quality of
wool
State where found
1 Lohi Good
quality wool
Rajasthan ,Punjab
2 Rampur
bushair
Brown
fleece
U.P ,HimachalPradesh
3 Nali Carpet wool Rajasthan, Haryana
,Punjab
4 Bakharwal For wollen
shawals
Jammu &Kashmir
5 Marwari Coarse
wool
Gujarat
6 Patanwadi For hosiery Gujarat

17. Processing fibres into wool
• Step :-1
• Shearing:-The fleece of
sheep along with a thin
layer of skin is removed
from its body. This
process is called
shearing.

18. • Premises and the shearing shed

19. Step:-2
Scouring:-The
sheared skin with
hair is thoroughly
washed in tanks to
remove grease,
dust and dirt. This is
called scouring.

20. • Thorough acid washing

21. Step:-3
Sorting:-After
scouring ,sorting
is done. The
hairy skin is sent
to a factory
where hair of
different textures
are separated or
sorted.

22. • Sorting of wool

23. Step:-4
The small fluffy fibres
called burrs, are picked
out from the hair. These
are same burrs which
sometimes appear on
your sweaters. The
fibres are scoured
again and dried. This is
the wool ready to be
drawn into fibres.

24. Step:-5
Dying:- the
fibres can be
dyed in
various
colours, as
the natural
fleece of
sheep and
goat is black
or white.

25. Step:-6
The fibres are
straightened,
combed and
rolled into yarn
.the longer
fibres are
made into
wool for
sweaters and
the shorter
fibres are spun
and woven
into cloth.

26. • shawl wool

27. SILK
• Silk fibres are also animal fibres .
• Silk worms spin the silk fibres .
• The rearing of silk for obtaining silk is
called sericulture.

28. • The common name is silkworm
• The Scientific Name of this silk worm is
Bombyx mori
Silk moth

29. Life History of Silk Moth .
There are four stages are present in the life
history of silk moth.
1. Egg stage
2. Larva or Caterpillar stage
3. Pupa or cocoon stage
4. Imago stage.

30. Egg stage

31. Egg stage
• Newly laid eggs are a creamy yellow, after
a few days the fertile live eggs will be
gray.
• Incubation period of the ova are 10-14
days.
• After 10-14 days the larvae will come out.

32. Larva or Caterpillar stage

33. Larva or Caterpillar stage
• After hatching, the tiny larvae grow the
best if they are fed on the new soft leaves
of the mulberry tree. (5 instars)
• The silkworms (larvae) do nothing but eat
for 27 days and
it will grow in size.

34. Pupa or Cocoon stage

35. Pupa or Cocoon stage
• The caterpillar secretes fibre made of protein
(fibrion and siricin) which hardens on
exposure to air and become silk fibre.
• The silkworm will spin a silk cocoon as
protection for the pupa. Cocoons are shades
of white, cream and yellow.
• It will be there in the cocoon for about 14
days.

36. • After a final molt inside the cocoon, the
larva change into the brown pupa. Further
changes inside the pupa result in an
emerging moth.

37. Imago stage

38. Imago Stage
• An adult silk moth emerges from the cocoon about two
weeks after completion. This is the adult stage of the
silkworm, Bombyx mori.
• The body of the moth is covered in short fine hair and
wings are creamy white with faint brown lines.
• Moths can not fly or consume nutrition. Females are
larger and less active than the males and the female will
lays eggs.
• The life cycle will continue.

40. Processing of silk
• Step-1
• A pile of cocoons are is used for obtaining
silk fibres .the cocoons are boiled or
exposed to steam.

41. Processing of silk
• Step -2
• REELING
• The process of taking out threads from the
cocoon for use as silk is called reeling the
silk.
• Reeling is done in special machines,
which unwind the threads or fibres of silk
from the cocoon.

42. Processing of silk
• Step-3
• Weaving.
• Silk fibres are spun into silk threads which
are woven into silk cloth by weavers.

43. ~~ ENDEND ~~