Sealant is an adhesive used by Bai to fill the configuration gap to seal Du. It is mainly composed of elastic sealant, liquid sealing gasket and sealing putty, which is deformed with the shape of sealing Dao surface, is not easy to flow and has certain adhesive property. Sealant has the functions of leak proof, waterproof, anti vibration, sound insulation and heat insulation, which is widely used in construction, transportation, electronic instruments and parts sealing.