The failure rate of composite insulators in China in 2008 is one in ten thousand. Although this data shows that the quality level of domestic composite insulators has reached a new height, the core technology of insulators still needs further development. Composite insulators are one of the important equipments for the safe operation of transmission lines, and their technical performance has received widespread attention from the power operation department and the manufacturing industry. With the wide application of rod-shaped suspension composite insulators, the pollution flashover accidents of transmission lines are declining year by year, and the reliability of safe operation is gradually improved. However, the hollow ceramic insulators used in substation equipment are difficult to meet the requirements of ultra-high voltage power equipment because of the difficulty in manufacturing. To solve this problem, learn from the successful operation experience of composite silicone rubber on the line. In 2004, domestic composite hollow insulators, composite pillar insulators, and composite silicone rubber climbing skirts began to be widely used in 110-550 kV substation equipment, and played an important role in curbing the occurrence of pollution flashover accidents.

There are more than 100 composite insulator manufacturing enterprises in China, but only more than 10 market-leading companies. The rapid development of the power grid has promoted the rapid growth of the composite insulator industry, making China's silicone rubber composite insulator manufacturing technology the world's leading level. Moreover, due to the large differences in the manufacturing level, quality management and operating conditions of silicone rubber composite insulators and the increasing number of composite insulators, the flashover and damage accidents of composite insulators have increased in recent years, manifested in flashover and mechanical strength. Dropping, breakdown, brittle fracture, deterioration and external force damage greatly affect the safe and reliable operation of the power grid. This also indicates that there are still some problems to be studied in the manufacturing technology of silicone rubber composite insulators.

Development history of composite insulators Before the 1990s, porcelain insulators were mainly used in China, and the amount of glass insulators was small, while composite insulators were still in the research and development stage. Rod-shaped suspension composite insulators began to enter the practical stage after 1995. Since then, the number of composite insulators has doubled in number. Especially since 2001, key manufacturing technologies such as integral injection molding, crimping connection, and various forms of sealing measures have matured and accumulated a large number of successful operating experiences, providing an opportunity for the promotion and application of composite insulators, making composite insulators become China is one of the most effective methods to solve the problem of external insulation pollution of transmission lines in polluted areas. After 2004, 300~550 kN products have been successfully developed, and domestic products have gradually occupied a leading position, leading the development of the world's composite insulator manufacturing technology.