Non-Conductive Material NHN Insulation Paper Under Allowable Voltage
NHN insulation paper is a material that is not electrically conductive under the allowable voltage, but it is not an absolutely non-conductive material. Under certain external electric field strength, conduction, polarization, loss, breakdown, etc. will occur, and long-term use will occur. Ageing. Its resistivity is very high, usually in the range of 1010 to 1022 Ω·m. In the motor, for example, the insulation around the conductor isolates the turns and isolates it from the grounded stator core to ensure safe operation of the motor.
Unsaturated polyester and epoxy resin were introduced after the 1940s. The emergence of powder mica paper has freed people from the plight of the lack of mica resources. Since the 1950s, synthetic resin-based new materials have been widely used, such as unsaturated polyester and epoxy insulation rubber for high-voltage motor coils. The polyester series products are used in motor slot lining insulation, enameled wire and impregnating varnish. The E-class and B-class low-voltage motor insulation has been developed to further reduce the volume and weight of the motor. Sulfur hexafluoride has been used in high-voltage electrical appliances and has been developed for large-capacity miniaturization. The air insulation of the circuit breaker and the oil and paper insulation of the transformer are partially replaced by sulfur hexafluoride.
The level of research and development of insulating materials is one of the keys that affect the development of electrical engineering. From the perspective of future trends, it is required to develop high-pressure-resistant, heat-resistant insulation, impact-resistant, environmentally-friendly insulation, composite insulation, corrosion-resistant, water-resistant, oil-resistant, cryogenic, radiation-resistant and flame-retardant materials, and research and development of environmentally-friendly and energy-saving materials. The focus is on the development of epoxy mica insulation systems for high-voltage large-capacity generators, such as FR5, phlogopite, etc.; F, H-class insulation series for small and medium-sized motors, such as unsaturated polyester resin glass mats; Gaseous medium of sulphur hexafluoride for electrical equipment; new non-toxic synthetic medium for replacing chlorinated biphenyl; high performance insulating oil; synthetic paper composite insulation; flame retardant rubber and plastic materials and surface protection materials, etc. The replacement of insulation materials for electrical equipment.
The cable paper is wrapped on the outer layer of the cable to protect the insulation of the conductive core from the insulation, so that the moisture is not invaded and the insulation is not damaged. For web. The basis weight is 45 to 175 g/m2. The paper is tough and even. High tensile, folding and tear strength. Contains no metals, sand and conductive acids. The dielectric constant is high. Low power factor. The paper has good stability when subjected to an insulating liquid treatment. The varieties are classified according to different thicknesses or colors. The unbleached sulphate softwood pulp is used as raw material, and after being beaten in a free form, it is not glued, and is not filled (material), and is formed on a long net paper machine. Used for turn-to-turn insulation of wires or cables.