Type of insulator is a kind of material which prevent the free electrons flow from atom to atom and molecule to molecule, if you want a charge is transferred to an insulator an a given location, the excess charge will remain at the initial location of charging.
Insulators are very important In transmission and distribution lines, the main function of electrical insulator is support wire and prevent electrical current back to the earth. These two functions must be guaranteed, so that extends the life of power system.
The types of insulator can be divided into four according to its different materials, four materials can be replaced each other:
Porcelain/ceramic electrical insulator
Glass insulator
Composite insulator or polymer insulator
HDPE insulator
Types of insulator classfied by structure:
Post electrical insulator
Suspension electrical insulator
Pin type electrical insulator
Shackle type electrical insulator
Stay electrical insulator
Line post electrical insulator
Hollow bushing electrical insulator
Crossarm insulator