Fibre to Fabric NCERT CBSE Class 7 Science Chapter 3 Summary Note

Fibre to Fabric


*Fibre-  Very thin thread.
             - Thread is prepared from it.
             - Examples- Cotton, wool etc.,

*Fleece- Hair on body of animals is called
                  fleece.
              - It keeps body of animals warm.

* Role of fleece
                 - Fleece traps air in it.
                 - Air is poor conductor of heat.
                - Air doesn't allow heat to lose out.
          Hence, body of animals remain warm.

* Types of fibres-
      (a) Natural fibres- Cotton, Jute, Silk, Wool.
      (b) Synthetic or Artificial fibre- Rayon,
                                                   tericot, Nylon etc.,

* Types of natural fibres-
     (a) Plant fibre- Cotton, Jute
     (b) Animal fibre- Silk, Wool.

*Selective breeding- 
      Selection of parents to get special
     characters in offspring, is called
      selective breeding.

* Rearing-
       The practice of giving shelter, food and
      medical care to animal, is called rearing.

* Breeding-
       The process of giving birth to young ones,
       is called breeding.

* Processing fibre into wool 
           Following steps are done to process   
            fibre into wool-
    (a) Shearing-
         Removal of fleece from animal body.
    (b) Scouring-
         -Washing sheared fleece.
         - Dust and dirts are removed.
    (c) Sorting-
        Arranging fibre according to size and
        texture.
    (d) Separation of burrs-
        Removal of small fluffy fibres(burrs) .
    (e) Dying-
        Applying colours to fibres.
    (f) Spinning-
     Preparation of wool thread from wool fibre.

* Sericulture-
     -Rearing of silkworm
     - to get silk from silkworm,
        is called sericulture.

* Life cycle of Silkworm
   
     Silkmoth ----------> Eggs ------> 
     Larvae/Caterpillar/Silkworm ----> Pupa
     Pupa ----> Pupa in cocoon ---> Silkmoth

 * Caterpillar or Silkworm-
     - Larvae of silkmoth. 
     - Hatched out from eggs. 

 * Pupa - 
    - Fully grown caterpillar. 
    - it form a cover called cocoon. 

* The most common silkmoth is- 
                               Mulberry silkmoth. 

 * Reeling of Silk-
     -The process of taking out threads  
       from the cocoon for use as silk is 
      called reeling the silk. 

 * Silk fibres are spun into silk thread. 
   Silk threads are woven into silk cloth. 





                   

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