The end seals of early composite insulators only used room temperature vulcanized silicone rubber or other sealants. With the continuous occurrence of brittle fracture of mandrel or string drop accidents caused by solid seal failure, major enterprises began to develop more effective sealing methods.
If HTV high temperature vulcanizate is used. Double sealing technology, end sealing and gluing technology, four-fold sealing structure, built-in or external. Sealing ring, etc. These measures effectively protect the connection between mandrel and metal accessories, and ensure the reliable operation of composite insulators.