7 Facts on Glass as an Insulator (Why and Uses)

Silicate glass is the most popular type of glass. In this piece, let us talk about the characteristics of glass as an insulator.

Glass is acknowledged as an exceptional insulator of both thermal conductivity and electrical conductivity in its natural occurrence. Nonetheless, glass can behave like a conductor and become a thermal and electric conductor when heated to extremely high temperatures.

Compared to metals, the rate of thermal conduction is slower in glass. Let us elaborate about some further information on glass’s ability to act as insulation in this post.

Why is glass a good electric insulator?

The insulator has an exceptionally high electrical resistance that is close to 1010 ohm meters. Let us discuss why glass serves as a good electrical insulator.

Glass is a good electric insulator due to the extremely low number of unused unpaired electrons. The glass’s atoms are connected by extraordinarily powerful electron connections. These electrons are not available for the exchange of ions to distribute or freely move around with.

Is glass a good heat insulator?

The amount of heat that is transferred through a substance per unit of time is known as the heat flow rate. Let us see the glass is thought to be a superior heat insulator.

Glass is recognized as a good thermal insulator as it conducts heat extremely slowly. Glass consequently shows that it can move swiftly in comparison to other items with essentially no movement.

Uses of glass as an insulator

Insulator materials do not allow to flow of current on a freeway. Let us list a few uses of glass as an insulator.

  • Glass is utilized in a variety of building projects as an insulator so that the temperature stays within a comfortable range.
  • Glass fibres are used for overhead insulation in electric lines.
  • Glass wool produced by binding fibres traps the small holes and acts as an insulation in form of slabs or rolls for batts or blankets in the ceilings.
Image – Glass;
Image Credit –Wikipedia

In the picture, Microscopically, a single crystal has atoms in a near-perfect periodic arrangement; a polycrystal is composed of many microscopic crystals; and an amorphous solid such as glass has no periodic arrangement even microscopically.

Is glass a better insulator than ceramic?

Vast amounts of ceramics are used in gas turbine engines. Let us explore about whether glass insulates better than ceramic.

Glass is a better insulator than ceramic with more resistance to breaking than ceramics and it also has a mechanical compressive strength that is 1.5 times greater than ceramic material.

Although most ceramic materials restrict the flow of electric current, porcelain and other ceramic materials have traditionally been used as insulating materials. Conversely, some ceramics exhibit high electrical conductivity.

When does glass conduct electricity?

Siemens per meter, or S.I., is the unit used to express electrical conductivity. Firstly, let us talk about when glass conducts electricity.

Glass can conduct electricity only when it is molten or very close to a melting point like conventional glass, such as Pyrex. Glass behaves exactly like an insulator at standard ambient temperature.

Any object’s conductivity may be stated using the formula σ = 1/ ρ. Electrical resistivity and conductivity are both represented in the statement by the symbols σ and, ρ respectively.

Frequent asked question

List some properties of glass.

Glass lasts a very long time. Glass does not age and its mechanical and electrical qualities do not change. Let us list some properties of glass material.

  • At normal room temperature, the density of the glass is 2.23 gram per cubic centimeter.
  • Melting point or softening point of the glass is 440 degree centigrade to 840 degree centigrade.
  • Thermal conductivity of the glass at 20 degree centigrade is 1.14 W/m ℃.
  • The specific heat for the insulator of glass is 1.0 × 103 J/kg/K.
  • The thickness of the glass is 1.6 mm.
  • The loss factor for the glass is 0.9.
  • The heat transfer coefficient for the glass is 1.0 × 10-5 J/mm2/K.
  • The laser absorption rate for the glass is 6.5 × 10-2.
  • The thermal expansion coefficient for the glass is 9.04 × 10-6 K-1.
  • The band gap for the glass is 2 – 3 eV.
  • The dielectric strength for the glass is 140 kV/cm.
  • The compressive strength for the glass is 10000 kilogram per square centimeter.
  • The tensile strength for the glass is 3500 kilogram per square centimeter.

Glass is a more affordable insulating material, after all. Air dust will collect on the wed glass surface as a result of moisture easily condensing on it, which will open a conduit for the system’s leakage current.


We can infer from the article’s conclusion that glass acts as an insulator. Glass simply behaves as an insulator at the typical room temperature of 25 degrees. This also covers other subjects, like when and how glass can transmit electricity. Glass cannot be formed in irregular forms at higher voltages because internal strains are created by inconsistent cooling. Glass is utilized in packaging, such as drink bottles and food jars, since it acts as an insulator.

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