The material used for cold-shrink cable accessories is silicone rubber, with high elasticity, good insulation performance, anti-leakage trace, hydrophobicity, weather resistance, UV aging. Heat shrinkable cable accessories are made of rubber and plastic composite materials (polymer) , the material itself is not elastic, only"Elastic memory" function. The electrical stress control unit has stable performance. The electric stress control unit of cable accessory is geometric type: stress cone, which depends on geometric curve to improve electric field distortion, and its shape has been formed in the company, so the performance of electric stress control unit is stable. The electric stress control unit of the heat-shrinkable cable accessory is a parameter type, that is, the electric stress control unit is formed by adopting the material with high dielectric constant and volume resistivity between the insulating material and the semi-conductive material, the special parameters of this material are difficult to control and are easy to change during molding and construction, which leads to the instability of the performance of the electrical stress control unit
