The evolution of porcelain insulator technology in Japan

Japan has succeeded in making homogeneous and high strength porcelain by pulverizing the raw materials into fine grains of micrometer order. Porcelain insulators manufactured with finer particle materials give superior mechanical and electrical strengths. The grain size of raw materials in Japan is much smaller than in Europe. The finer grain size of the raw materials causes higher viscosity slip, which requires higher levels of manufacturing techniques in forming, drying, firing, and so on. Japan has succeeded in establishing the higher level techniques required to make higher quality porcelain. Japan started to manufacture quality porcelain insulators by adding alumina to the conventional porcelain to improve the thermal and mechanical performance. Through these efforts, Japanese insulator technoiogy has gained a leading position in the world. The article introduces the evolution of each kind of insulator in Japan.>