Conveyor belts are generally composed of three parts: skeleton material, overlay and laminate material (hereinafter referred to as "overlay" and underlying material). Among them, skeleton material is the key to the carrying capacity of conveyor belts, and is the decisive factor for the guiding, loading ability and extensibility of conveyor belts; overlay material is the assurance of normal operation of conveyor belts, with maintenance skeleton material and conveyor material. Increase friction coefficient, absorb material impact, anti-wear and other effects, the characteristics of conveyor belts such as high temperature resistance, wear resistance, anti-static, etc. all depend on the characteristics of the coating material; the effect of undercutting material is to make the framework material and the coating have outstanding bonding strength.