In order to isolate the core of the conducting material different types of insulation are used in cable manufacturing. Insulation creates a dielectric medium between the conductor and its surroundings. Different types of insulating materials are used which are relative to the characteristics of electric cables. Mostly, the insulating materials are characterized as thermoplastic or thermoset. Thermoplastic materials are actually those materials which change their state when subjected to heat. However, thermoset materials are those which remain the same even after being subjected to heat. Some of the types of insulations will be discussed as follows: –
- Polyvinyl Chloride (PVC)
The most commonly used material for insulation is polyvinyl chloride insulation. It is cheap and contains thermoplastic characteristics. Chlorine in Polyvinyl Choline (PVC) adds the qualities to become thick, toxic and black when subjected to high temperatures.
2. Cross-linked Polyethylene
Polyethylene is another important insulating material that contains polyolefins. Due to these polymers, it has lesser losses than Polyvinyl Chloride (PVC). It falls in the category of thermoset and is not affected by heat. Crosslinked Polyethylene (XLPE) is actually named crosslinked due to its composition, the polyethylene chains are linked in such a way that it prevents the polymer from being affected by high temperature.
A combination of ethylene and polyethylene forms a polymer called elastomer. It is also expressed by EPR and due to the combination, the formed polymer is more flexible, lesser in losses and has better sustainability at higher temperatures ranging.
Paper extracted from wood is a highly insulating material. It was one of the oldest ways of insulating the conductors. Still, It is used in the insulation of high voltage cable manufacturing but with some dielectric fluid attached along with it. Another insulation of lead sheath is applied on this paper insulating material to protect the cable from moisture damages.