Wednesday, May 9, 2012

Class 6 - Science - CH3 - Fibre to Fabric

Cotton Bolls

NCERT Chapter Solutions and other Q & A

Q1: What is a fibre?
Answer: A fibre is a thread which can be spun into strings, rope and clothes. A fibre can be obtained naturally or artificially.

Q2: Define Natural Fibres.
Answer: The fibres which we obtain from nature i.e. from animals and plants are called natural fibres.

Q3: Classify the following fibres as natural or synthetic:
     nylon, wool, cotton, silk, polyester, jute

Answer: Natural Fibres:  wool, cotton, silk, jute
            Artificial Fibres:  nylon, polyster

Q4: State whether the following statements are true () or false ():
a) Yarn is made from fibres. ()
b) Spinning is a process of making fibres. ()
c) Jute is the outer covering of coconut. ()
d) The process of removing seed from cotton is called ginning. ()
e) Weaving of yarn makes a piece of fabric. ()
f) Silk fibre is obtained from the stem of a plant. ()
g) Polyester is a natural fibre. ()

Q5: Fill in the blanks:
a) Plant fibres are obtained from__jute__ and _cotton_ .

Jute Sack Back
b) Animals fibres are _silk__ and _wool_ .

Q6: From which parts of the plant cotton and jute are obtained?
Answer: Cotton is obtained from the fruits of the cotton plant, called cotton balls. Jute fibre is obtained from the stem of the jute plant.

Q7: Name two items that are made from Jute fibre.
(i) Jute Sack bags
(ii) Ropes

Q8: Name two items that are made from coconut fibre.
Answer: Coir is the natural fibre obtained from coconut husk. Items made from coir (coconut fibre) are:
(i) Coir Mattresses
(ii) Mats
(iii) Baskets

Q9: Explain the process of making yarn from fibre.

Answer: The process of making yarn from fibres is called spinning. In this process, fibres from a mass of cotton wool are drawn out and twisted. This brings the fibres together to form a yarn.

Spinning is done at home using simple devices like hand spindle (Takli) and charkha. On large scale big spinning machines are used.

See youtube video showing how spinning is done from a cotton mass.

Q10: Name the processes involved in making cotton fabric from cotton bolls
  1. Hand Picking Cotton Bolls: When cotton bolls mature, they burst out white cotton fibre. These bolls are hand picked.
  2. Ginning: It is the process of removing cotton seeds from bolls. The seedless cotton mass is combed into lints and bales.
  3. Spinning: It is the process of turning cotton mass into yarn. It is done by home made spinning machines like takli or charkha. At large scale big spinning machines are used.
  4. Weaving and Knitting: The process of combining two sets of yarns is called weaving. It is done on a machine called loom (handloom or powerloom).In knitting, single fibre is used to prepare a fabric. Knitting can be done by hand or by knitting machines.
From Cotton Boll to Fabric

Q11: Synthetic fibers are obtained from ___.
(a) Animals
(b) Plants
(c) Petroleum
(d) All of the above

Answer: (c) Petroleum