The general wire and cable is insulated with plastic and rubber. These materials are conventional engineering materials, have a rich source, can meet large-scale production, and the cost is relatively low. However, for some special industries such as petrochemical, steel, aerospace, shipbuilding, military, pharmaceutical, food, plastic machinery, boilers and other industries related to heat and high temperature, wire and cable that can withstand a certain higher temperature, ordinary wires are needed. The cable is obviously not usable, and it is necessary to be able to withstand high temperature wires and cables to ensure the safe operation of its power and signals.
With the rapid development of China's economy, the demand for high-temperature cables in special industries has increased rapidly, and heat-resistant and high-temperature cables have grown at a rate of 20% per year. High-temperature cables are an important part of special cables and have strong vitality. In short supply, China imports about 2 billion yuan from abroad for domestic construction. The International Electrotechnical Commission (IEC) general rules for the heat resistance of insulation are divided into:
Heat rating YAEBFHC
The maximum allowable working temperature / °C90105120130155180 ≥ 180 Our common wire and cable insulation and sheath is common engineering rubber and plastic as the basic resin, but the requirements are insulation grade. Common rubber materials for cable are: Ding Ben rubber, ethylene propylene rubber, natural rubber and chlorosulfonated polyethylene, etc., working temperature is (60 ~ 75) ° C; common cable plastic materials are polyvinyl chloride, polyethylene (including Bi-polyethylene) and polypropylene, etc., the working temperature is (70 ~ 90) °C. It can be seen that these cables are not heat resistant or high temperature cables in the strict sense.
Heat resistant cables generally refer to cables (90 to 155) ° C and below, while high temperature cables are cables of 180 ° C and above. To solve the problem that ordinary cables are not resistant to high temperatures, it is necessary to improve the materials or use insulation grade materials that can withstand high temperatures.