Polymer insulators (also called composite or nonceramic insulators) consist of a fiberglass rod attached to two metal end fittings

covered by a rubber weathershed system. Polymer insulators were first developed in the 1960s and installed in the 1970s.

Polymer insulators, also known as composite insulators, are different from porcelain insulators in that they are composed of a 

polymer rain-proof sheath and a mandrel of resin material. It is characterized by not easy to accumulate water, high resistance 

to fouling and light weight. At present, Japan is not only promoting the use of electrified railways, but also the power sector,

and it is expected to become a new insulating material (for catenary) in the future.

Applications

The conductors of overhead power lines are connected and fixed on the tower by insulators and hardware.Insulators used for 

the insulation of wires and towers must not only withstand the action of working voltage, but also be subjected to the action 

of overvoltage during operation,and also bear the action of mechanical force, temperature changes and the influence of the

surrounding environment, so the insulator must be in good condition. insulation properties and certain mechanical strength.

Usually, the surface of the insulator is corrugated.

This is because: First, the leakage distance (also known as the creepage distance) of the insulator can be increased, and each 

wave strand can also play a role in blocking the arc;

The second is that when it rains, the sewage flowing down from the insulator will not flow directly from the upper part of the 

insulator to the lower part, so as to avoid the formation of sewage columns and cause short-circuit accidents, and play a role 

in blocking the flow of sewage;

The third is that when the pollutants in the air fall on the insulator, due to the unevenness of the insulator, the pollutants will 

not be evenly attached to the insulator, which improves the anti-pollution ability of the insulator to a certain extent. There are 

many types of insulators for overhead power lines,which can be classified according to the structure type, insulating medium,

connection method and bearing capacity of the insulator.

Rod-type insulators are used in high-voltage transmission lines and can be used in areas with different pollution levels. 

They have the characteristics of light weight, small size, not easy to break, high tensile strength, and strong pollution

performance.