Fibres
Fibres are thin, long, and flexible and hair or thread-like structures. There are two types of fibre:-
1. Natural, 2. Man-made
1. Natural Fibres
The fibres which are obtained from natural sources such as plants are known as natural fibres.
Example:- Cotton, wool, silk, etc.
2. Man-made fibres
The fibres which are manufactured in factories by humans are known as man-made or Synthetic fibres.
Example:- Nylon, Rayon, acrylic, etc.
Synthetic Fibres:
Synthetic fibres are made by humans through the chemical synthesis in laboratories and factories.
Plastic
The word plastic comes from the Greek word “plastikos” which means fit for moulding. Plastic is popular because it is cheap to produce and is easy to mould and shape into the desired form.
Types of plastics:
There are two types of plastics:- 1. Thermoplastics, 2. Thermosetting polymers
1. Thermoplastics
The polymers in which the intermolecular forces of attraction are intermediary to those of elastomers and fibres are called thermoplastics. Thermoplastics can be formed into any shape by heating.
Example: Polythene, PVC, Teflon, etc.
Uses: They are used in making toys, combs, containers, etc.
2. Thermosetting polymers
The polymers which on heating change irreversibly into hard, rigid, and infusible
materials are called thermoplastics. Once they are moulded they cannot be changed into other forms.
Example:- Bakelite, melamine.
Uses:- They are used in making switches, handles, and utensils.

Assignment: 1.link for liveworksheet on synthetic fibres & plastics :https://images.app.goo.gl/bCE3j4Uk8wZ6B9Tm8      
2.Link for Quiz on the topic synthetic fibres & plastics:
https://quizizz.com/join/quiz/5f142c2f24ca86001b35bfd4/start?studentShare=true