Insulating materials in the early 20th century, with the development of European and American electrical industry with the emergence of the modern electrical industry “vascular and heart” of the main components. It’s very commoto see in our daily life like “wire layer indoor”, “inside and outside wall insulation sleeve”, “Touch and low-voltage electrical plastic”, “height of the insulator,” etc., are of insulating materials, but these only the “tip of the iceberg.
More precise definition of insulating materials are: volume resistivity of the material 109 ~ 1020 Ω • m posed by substances in electrical insulating materials is technically called, also known as the dielectric. The insulating material has a very large direct current resistance, in the DC voltage applied, in addition to the outer surface leakage tiny, virtually nonconductive, and for alternating current through the capacitive current, but is not considered conductiv.
In long-term use of insulating material, inevitably subject to temperatures of various factors electricity, mechanical stress and vibration, harmful gases, chemicals, moisture, dust, radiation, etc. and high performance insulating materials, and electronic products are essential materials, is the key to determine the operational reliability of the material.