Fibers and Fabrics

  • The clothes are made from the fabrics.
  • Later fabrics are formed from fibres which are obtained from artificial and natural sources.

Types of fibres

 Science Class 8 Synthetic Fibres and Plastics

  1. Natural Fibres
  • Natural fibres are obtained from the natural resources.
  • Examples – wool, silk, cotton, etc.

Science Class 8 Synthetic Fibres and Plastics

  1. Synthetic Fibres
  • Synthetic fibres are man-made.
  • Examples – nylon, acrylic, rayon, etc.
  • When small units of chemicals join together in a large chain then synthetic fibres are formed.
  • The chain formed is called as polymer. Polymer is a Greek word where ‘poly’ means many and the word ‘mer’ means units.

Science Class 8 Synthetic Fibres and Plastics

Types of Synthetic Fibres

  1. Rayon
  • When the wood pulp is treated chemically then rayon is obtained.
  • Rayon is cheaper than silk
  • Bed sheets are made with the mix of rayon and cotton.
  1. Nylon
  • It is used for making bristle of the toothbrush.
  • Also used in making ropes, socks, clothes, curtains, sleeping bags, etc.
  1. Polyester
  • When units are repeated chemically then polyester is formed.
  • It is used to make the insulating material in pillow, ropes, etc.
  1. Acrylic
  • It is also named as synthetic wool or artificial wool.
  • The clothes obtained from acrylic are quite cheaper than the clothes formed from wool
  • It is used to make blanket, sweaters, etc.

Characteristics of synthetic fibres

  1. Synthetic fibres are quite cheaper
  2. They are considered to be stronger and reliable.
  3. They are easy to wash and maintain.
  4. Also easy to carry and readily available.

 

Plastics

  • Plastic is also a polymer.
  • Some plastics have a linear arrangement of units and some have cross-linked arrangement
  • It is used to make suitcase, toys, cabinets, brush, bags, tables, chairs, etc.
  • One of the most known and famous examples of plastic is polyethylene which is used in the formation of carry bags.

Science Class 8 Synthetic Fibres and Plastics

Types of plastic

  1. Thermoplastic
  • These plastics which easily get bent or deform with heat.
  • PVC and polythene are the examples
  • It is used to make containers, bottles, toys, etc.

Science Class 8 Synthetic Fibres and Plastics

  1. Thermosetting plastic
  • Once mould cannot be reframed by heating.
  • These are used to make an electric switch, floor tiles, hardboard, etc.
  • Bakelite and melamine are the examples of Thermosetting plastic

Science Class 8 Synthetic Fibres and Plastics

Characteristics properties of plastics

  • Plastic is strong, light and durable.
  • It is non-reactive
  • Plastic is a poor conductor.

Plastic uses in various fields

  • A plastic called Teflon is used in making Nonstick coat on the cookware.
  • Melamine plastic is used in the uniforms of firemen which make them flame resistant.
  • In the making of microwave ovens, special plastic cookware is used for cooking food.
  • It is also used in the healthcare industry for packaging of threads, tablets, syringes, etc.

 

Recap

  • The clothes are made from the fabrics.
  • Later fabrics are formed from fibres which are obtained from artificial and natural sources.
  • Synthetic fibres are quite cheaper
  • They are considered to be stronger and reliable.
  • Plastic is also a polymer.
  • Some plastics have linear arrangement of units and some have cross-linked arrangement
  • It is used to make suitcase, toys, cabinets, brush, bags, tables, chairs, etc.