1. Combustion resistance refers to the ability of insulating materials to resist combustion when in contact with flames or prevent continued combustion when they leave the flames. With the ever-expanding application of insulating materials, the requirements for their combustion resistance become more important. People use various means to improve and enhance the combustion resistance of insulating materials. The higher the combustion resistance, the better the safety.
2. Arc resistance The ability of the insulating material to withstand the arc action along its surface under the specified test conditions. In the test, AC high voltage and small current are used, and the arcing effect generated by the high voltage between the two electrodes is used to determine the arc resistance of the insulating material by the time required to form a conductive layer on the surface of the insulating material. The larger the time value, the better the arc resistance.
3. Sealing degree The sealing and isolation of oil and water quality is better.
4. Breakdown voltage and electric strength In a certain strong electric field, the insulating material breaks down and loses its insulating properties and becomes a conductive state, which is called breakdown. The voltage at breakdown is called breakdown voltage (dielectric strength). Electric strength is the quotient of the voltage when breakdown occurs under specified conditions and the distance between the two electrodes that bear the applied voltage, that is, the breakdown voltage per unit thickness. For insulating materials, the higher the breakdown voltage and electrical strength, the better.
5. Tensile strength is the maximum tensile stress that the sample bears in the tensile test. It is the most widely used and representative test for the mechanical properties of insulating materials.
6. Insulation resistance and resistivity. Resistance is the reciprocal of conductance, and resistivity is the resistance per unit volume. The less conductive the material, the greater its resistance, and the two are in a reciprocal relationship. For insulating materials, it is always desirable to have the highest resistivity as possible.
7. Relative permittivity and dielectric loss tangent: the mutual insulation of the various components of the electrical network and the medium of the capacitor (energy storage). The former requires a small relative permittivity, the latter requires a large relative permittivity, and both require a small dielectric loss tangent, especially for insulating materials used under high frequency and high voltage, in order to make the dielectric loss small, both require the use of Insulating material with a small dielectric loss tangent.