High-voltage and medium-voltage cables (accessories and sealants)

High-voltage cables (above 1 kV, reaching hundreds of kV in energy transmission) use combinations of insulating materials where PU appears in specific applications: as primary insulation in medium-voltage cables (1-35 kV), in terminations and joints (points where cables are connected — high electrical stress area), in external mechanical protection coatings, and increasingly in high-voltage cables for automotive applications (EVs with 400V to 800V+ batteries). They compete with cross-linked polyethylene (XLPE, dominant standard in transmission), EPR, and in some applications with silicone rubber. PU offers advantages in specific applications: superior flexibility (important in cables that need to be handled in the field), better mechanical resistance, adjustable dielectric properties. In EVs, high-voltage cables connecting battery to inverter and motor need to combine flexibility, oil resistance, vibration durability and dielectric properties — area of strong growth.