Performance Of High-quality Insulating Paper

The quality of the insulating paper determines whether the transformer work is carried out normally. Its quality is essential for transformer’s service life. So, what are the performances of an excellent insulating paper?

1. It should have strong burning resistance.

The material should have the ability to resist or stop burning when the insulating material contacts the flame since the higher the flame resistance, the safer.

2.It should have high insulation resistance.

Resistance is the reciprocal of conductance, and resistivity is the resistance per unit volume. The smaller the material's conductivity, the greater its resistance. For insulating materials, it is always desirable to have the highest resistivity.

3. It should have good tensile strength.

In the tensile test, the sample should bear a large tensile stress, and this is a very representative and commonly-used test for the mechanical properties of insulating materials.

In addition, excellent insulating paper should also have good arc resistance. Under specified conditions, it should be able to withstand the arc action along its surface. During the test, the AC high voltage and small current are used. The high voltage arc generated between the two electrodes forms a conductive layer on the surface. And judging by the time needed to form that conductive layer, we could value its arc resistance. The longer the time is, the better the arc resistance.