Class 6 Science
A material which is available in the form of thin and continuous strand is called fibre.
Natural fibers: The fibers which are obtained from plants and animals are called natural fibers. Examples: cotton, jute, silk, wool.
Plant Fibre: Cotton and jute are plant fibre.
Animal fibre: Silk and wool are animal fibre.
Synthetic fibre: The fibre which are synthesized in industry from simple chemicals obtained from petroleum are called synthetic fibre. Examples: Nylon, Acrylic, Polyester
In India, cotton is cultivated mainly in Maharashtra, Gujarat, Haryana, Punjab, Rajasthan, Tamil Nadu and Madhya Pradesh.
Cotton is cultivated in black clayey soil. It needs warm climate. The sowing of cotton crop is done in early spring. Cotton plants are bushy and about 1-2 meters tall. The plants start flowering in about 60 days and give whitish - yellow flowers. The flowers turn reddish in a few days. Flowers slowly grow into spherical walnut-like structures. These are called cotton ball. Fibres of cotton grow on these seeds. After some time green cotton balls turn brown. At maturity, the cotton bolls burst open and the white cotton fibre can be seen.
Ginning: The cotton picked up from the plants has seeds in it. The process of removing cotton seeds from pods is called ginning. Ginning was traditionally done by hand. Now-a-days, machines are used in ginning.
Spinning: The process of making yarn from fibre is called spinning. The raw cotton is supplied to industry in the form of bales.
Weaving: The process of arranging two sets of yarn together to make a fabric is called weaving. The big reels of yarn are called bobbins. These bobbins are used for weaving the cloth. Cloth is woven on looms. After that they bleached and dyed to give a finish.
Knitting: Knitting can be done by hand and machine. Just two yarns are used in knitting, while more than two yarns are used in weaving. Sweater, socks, scarf and caps are knitted from the wool.
Uses of cotton: Cotton is mostly used for making clothes of various kinds. Examples: towels, bed-sheet, curtains, saris.
Jute fiber is obtained from the stem of the jute plant. It is cultivated in rainy season. Jute is grown in alluvial soil which is found usually in the Delta Region of the Ganges and Brahmaputra rivers. In India, jute is mainly grown in west Bengal, Bihar and Assam. Jute plants are about 2.5 to 3.5 meter in height. It bears yellow flowers in 3 to 4 months. Jute plants are usually cut at the flowering stage. A good quality fiber is obtained from plants which are cut at the flowering stage. After falling of dry leaves bundles of dry plants are kept in a pond for a few days. In this period the gummy skin rots out to separate the fibre. This process is called retting.
The jute fiber is obtained from the retted jute by hand. Jute fibre is pale- yellow in colour and 2to 3 meter long. Jute fibre is very strong. Jute fibre has silky texture.
Jute fiber is used mainly for making gunny bags, shopping bags, ropes, carpets, curtains, etc.
We get wool from hair of the sheep, goat, rabbit, yak and camel. Wool is used for making warm clothes, such as sweater, cap, shawl, gloves, and blanket, etc. Wool is also used in making carpets and upholstery.
We get silk from silk worm. Silk fiber is obtained from the cocoons of the silk moth. The silk moth lives on the leaves of mulberry plants. There are four stages in the life cycle of silk moth: eggs, larva, pupa and adult.
The larva of the silk moth is called caterpillar. It secretes a sticky fluid fibroin from its salivary gland (silk gland). This sticky fluid forms a long thread. This thread is wrapped around the body of the caterpillar and forms cocoon. After this stage, the larva becomes a pupa and then turns into an adult moth.
Silk is a costly fabric. Silk fiber is used for weaving cloth; especially traditional dresses in India; like sari, kurta, shawl and other wedding clothes. Silk had always been prized for its luster and fine quality.
Synthetic fibre is quite strong, wrinkle- resistant and quick drying. These are used in making different materials; like clothes, neck-ties, sails, sweater, shawls, carpet and blankets. They are also used in making boats, skating boards, etc.
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