1, insulation resistance and resistivity
The resistance is the reciprocal of the conductance, which is the resistance per unit volume. The smaller the material's conductivity, the greater its resistance, and the reciprocal relationship between the two. For insulating materials, it is always desirable to have the resistivity as high as possible.
2. Relative dielectric constant and dielectric loss tangent
There are two uses for insulating materials: the mutual insulation of the components of the electrical network and the medium of the capacitor (storage energy). The former requires a relatively small dielectric constant, the latter requires a relatively large dielectric constant, and both require a small dielectric loss tangent, especially for insulating materials applied at high frequencies and high voltages. Insulation material with a small dielectric loss tangent.
3, breakdown voltage and electrical strength
In a strong electric field, the insulation material is destroyed, and the loss of insulation performance becomes a conductive state, which is called breakdown. The voltage at the time of breakdown is called the breakdown voltage (dielectric strength). The electrical strength is the quotient of the voltage between the two electrodes when the breakdown occurs under the specified conditions and the voltage applied to the external application voltage, that is, the breakdown voltage per unit thickness. For an insulating material, generally, the higher the breakdown voltage and electrical strength, the better.
4, tensile strength
It is the maximum tensile stress that the specimen is subjected to during the tensile test. It is the most widely used and representative test for the mechanical properties of insulating materials.
5, resistance to combustion
Refers to the ability of an insulating material to resist burning when it contacts a flame or when it leaves the flame. With the increasing application of insulating materials, the requirements for their resistance to combustion are more important, and various methods have been used to improve and improve the flame resistance of insulating materials. The higher the resistance to combustion, the better the safety.
6, arc resistance
The ability of an insulating material to withstand arcing along its surface under specified test conditions. During the test, an alternating current high-voltage small current is used to determine the arc resistance of the insulating material by the arc generated by the high voltage between the two electrodes to make the conductive layer form a conductive layer. The greater the time value, the better the arc resistance.
7, sealing degree
Sealing isolation of oil quality and water quality is better.