5 Facts On Plastic As An Insulator(Why And Uses)

Some materials exhibit a property of not allowing energy transfer, such material is called an insulator. Let us know whether plastic is an insulator or not.

Plastic is an insulator because it allows neither electricity nor heat to transfer through them to any other material by efficiently holding the electrons from moving. Also the composition of plastic consists of carbon, oxygen, and hydrogen which has no free electron in the valance shell.

Let us discuss some more facts about why plastic is an insulator, its uses, and the circumstances in which plastic acts as an electric conductor.

Why is plastic a good electric insulator?

Plastic is a man-made polymer as a long chain atom packed together to form a flexible solid. Let us find the reason behind the electric insulating nature of plastic.

Plastic is a good electric insulator because they have no free electron at the outer valance shell. All the electrons are tightly bounded to their nucleus so that there is no random movement of the electron is possible to carry the charges to conduct electricity.

In plastic, the forbidden energy gap between the valance and conduction band is very large, so the electrons cannot jump easily towards the conduction band, thus conduction of electric current is quite not possible in plastic.

Is plastic a good heat insulator?

A heat insulator is material in which no heat can transfer through them. Let us check whether plastic allows heat flow o not.

Plastic is indeed a good heat insulator because they consist of no free electrons which can move randomly in the lattice restricting the heat flow as all the electrons are trapped inside due to the presence of air bubbles present in the polymer molecule.

Uses of plastic as an insulator

Plastic is a non-biodegradable material that has a wide range of applications as an insulator. Let us provide a list of uses of plastic as an insulator.

  • Plastic is used as insulation for electric wires.
  • Kitchen utensils use plastic handles as they provide good thermal insulation.
  • Electric switches and plugs are made of plastics.
  • Thermosets are made using multiple layers of plastic to prevent the amount of heat transfer, so that food can be kept warm. 

Certain types of plastic such as Mylar, Melinex, and Polyester films are widely used as an insulator as they are eco-friendly and durable. The air conditioners are also made using a plastic polymer as they can withstand up to certain high temperatures without melting.

Is glass a better insulator than plastic?

The ability to hold the energy without any leakage of the energy specifies a material as a good insulator. Let us check which is a better insulator, glass or plastic.

Glass is definitely not a better insulator than plastic as the atomic arrangement in glass is more regular than that of plastic, such that plastic can hold more electrons and can restrict them from moving more than glass.

Glass can absorb more amount of heat and loses its insulating behavior more rapidly 100 times quicker than the plastic.

When does plastic conduct electricity?

Under certain circumstances, an insulator can also conduct electricity. Let us study the situation of plastic conducting electricity.

  • The mixing of plastic material with highly conductive material can cause the plastic to conduct electricity.
  • When sufficiently high voltage is applied to the plastic, it acquires huge amount of energy to set free electrons, then conduction of electricity is possible in plastic.


Let us wrap this post by stating that plastic is one of the best insulators whose conductivity is much lower than glass and wood. The heat trapping ability of plastic is more because of the air bubbles.

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