Because it fills heat slowly
insulator
Plastic is a non conductor of electricity.
The opposite of a conductor (conducts electric flow) is a non-conductor, or something that opposes the flow, which would be an insulator.
Conductor
Plastic is made out of organic (carbon based) molecules which hold on to their electrons rather than contributing them to a common pool as metals do. Hence you do not get the kind of electron mobility needed for electrical conductivity.
bowl is conductor
is a pen a insulator of conductor
Plastic is an insulator.
Plastic is an insulator.
Plastic is an insulator.
Plastic is an electrical and thermal insulator.
Insulator
It is an insulator
insulator
insulator
insulator
conductor