Porcelain insulators were first used on telegraph lines in 1849. In the 1990s, the trimming process for domestic porcelain insulator production relied entirely on manual hammering. In the early 2000s, domestic enterprises began tackling key technical challenges to meet the demands of UHV (Ultra-High Voltage) infrastructure construction. In 2010, companies such as Sinoma Electric Porcelain undertook the development of UHV rod-type insulators; through process improvements, they achieved high pass rates for million-volt products. These products were successfully deployed in early projects-such as the Jindongnan–Nanyang–Jingmen 1000kV UHV AC pilot project-thereby breaking the monopoly held by foreign manufacturers.
Production techniques subsequently underwent a transformation from "horizontal natural air-drying" to "vertical electric drying," resulting in significantly improved moisture uniformity and production efficiency. The introduction of intelligent equipment, such as dual-station fully automatic trimming machines, marked the shift from manual hammering to intelligent manufacturing. By establishing R&D centers and increasing investment in research, enterprises overcame technical hurdles-developing products such as resistor elements for 550kV (and above) circuit breakers and inorganic-bonded hollow porcelain insulators for 750kV and 1000kV applications-thereby filling gaps in the domestic market. Sinoma Electric Porcelain established a large-scale, fully automated production line and an intelligent production management platform for UHV insulators.
Currently, domestic porcelain insulator technology has reached a world-leading level, featuring a product portfolio that covers the entire voltage range from 10kV to ±1100kV. Domestically produced insulators have been successfully utilized in major power projects both at home and abroad, including the Changji–Guquan ±1100kV UHV DC transmission project and the Belo Monte ±800kV UHV transmission line in Brazil. Sinoma Electric Porcelain has become a qualified supplier to Terna (Italy's national grid operator), and its product series-such as blue-grey glazed insulators-are exported to over 20 countries and regions worldwide.
