The development of rail transit industry is an important embodiment of a country's modernization process. In the rail transit industry, insulating materials are used in many units, such as traction motors, module motors, equipment power control modules, control boxes and cable trunking in the interior of carriages and around the track. With the rapid, safe and lightweight development of rail transit industry, insulation materials play an increasingly important role in this industry. Friend’s insulation materials ensure the safe operation of rail locomotives with stable and high-quality performance.