Insulation Materials Apply
The insulating materials used by electricians are divided into inorganic insulating materials, organic insulating materials and mixed insulating materials according to their chemical properties. Commonly used insulation materials: shellac, resin, rubber, cotton yarn, paper, hemp, artificial silk, mostly used to make insulating paint, winding conductor's covered insulator, etc. The mixed insulation materials are made of various molding insulation materials, which are used as the base and shell of the electric appliance.
Application of insulating materials
The role of insulating materials is to separate electrically charged parts from different electric potential in electrical equipment. Therefore, the insulation materials should have high insulation resistance and high pressure resistance, and can avoid accidents such as leakage of electric leakage and spraying machine. Secondly, it is better to avoid aging due to prolonged overheating. In addition, it should also have good thermal conductivity, moisture resistant, high mechanical strength and convenient process. According to the above requirements, the performance indexes of the commonly used insulating materials have insulation strength, tensile strength, specific gravity, expansion coefficient, etc.
Insulation resistance strength: the higher the voltage on both ends of the insulator, the greater the electric field force is in the material, and the more likely it is to collide, causing the insulator to break through. The lowest voltage that causes an insulator to penetrate is called the breakdown voltage of this insulator. For the breakdown of a 1mm thick insulating material, the number of voltages to be added is called insulation resistance strength of the insulating material, or the strength of insulation. Due to the dielectric strength of insulation material has certain, all kinds of electrical equipment, all kinds of safe appliance (electrician tongs, test pen, insulating gloves, insulated rod, etc.), all kinds of electrical materials, manufacturers stipulate certain allows the use of voltage, referred to as the nominal voltage. The voltage under use shall not exceed its rated voltage value to prevent accidents.
Tensile strength: the tensile strength of the unit area of the insulation material, for example, the area of glass per square centimeter can withstand 1400 newtons of tension.
Characteristics of insulating materials
According to the national standard GB2900.5, the definition of insulating materials is: "the material used to insulate the device on the electrical device". It's the material that stops the current from passing. The resistivity is very high, usually in the range of 10 to 10 Ω m.. Its characteristics mainly include the following:
< 1 > < 2 > gloss, resistance to chemical erosion part of transparent or translucent < 3 > mostly good insulators < 4 > light weight and strong < 5 > easy processing can be mass-produced, cheap < 6 > versatility, utility, easy coloring, some more resistant to high temperature < 7 > store goods can have the effect of moisture.
The insulation properties of insulating materials are closely related to the temperature.
The higher the temperature, the worse the insulation performance. In order to ensure the insulation strength, each insulation material has an appropriate maximum allowable working temperature, which can be used safely for a long period of time. According to the degree of heat resistance, the insulation material is divided into Y, A, E, B, F, H, C and so on.