Page 26 - Science Class 07
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parachutes and also as blanket filling and female moth can lay about 50-100 eggs at a
nowadays, it is used as a material in surgical me. The eggs hatch into larvae a er about 20
appratus and bicycle res. Always regarded as days. The larvae feed on mulberry leaf. A er a
an item of luxury and one of the most few days these cocoons start developing silk
important commodi es traded in the ancient filament around their bodies. At this stage they
world, silk was the e that brought together a ain one-third of their actual body size. Each
Ancient China and the West. cocoon may contain up to 3 km (2 miles) of silk
The origin of making tensile from silk was filament.
discovered in China around 2,500 B.C. and the
process was kept secret and monopolised by
the Chinese un l it gradually spread to Japan
and India in the third and fourth centuries A.D.
The art of making silk reached Europe in the
sixth century A.D.
Sericulture
Sericulture means cul va on of silk through
rearing of silkworms. The technique involves
plan ng of plants on which the silkworms
Silk is Obtained from Silkworms.
grow, produc on of cocoons, reeling and
spinning of cocoon for produc on of yarn. The
Produc on of Silk
word silk sounds so luxurious and classic. The
luster and elegance of silk is so outstanding and Silk filament is unwound carefully from the
body of the cocoon, for this the cocoons are
it cannot be compared with any other fabric. As
put into hot water to kill the pupae and remove
long as our desire for silk garments con nues,
the demand for sericulture will remain ac ve. the gummy coa ng. Therea er, the filament
are reeled. This process may be carried out by
Silk is known to be the queen of tex le and the
hand, but it is also done in small factories called
naturally produced animal fibre.
filatures. The filament from several cocoons,
the number depending on the thickness of raw
silk, are unwound and twisted together to give
a stronger silken thread, though this is s ll
almost invisibly fine, which is known as raw
silk. The threads of raw silk are too fine for
tex le manufacture and they are usually
doubled or thrown to produce a stronger and
thicker fibre. Throwing is a term used when the
raw silk is twisted into a strand for weaving
Larvae on Mulberry Leaf
purposes. This prevent the silk from spli ng
The female species of the silk moth is shorter into individual fibres. Silk is then woven in
and stouter than its male counterpart. The much be er way than any other tex le.
26 Science-7
