Before starting: (A) Check whether the screen is damaged or not (B) Whether each set of lashing rings is locked; 2. When starting: (A) pay attention to whether there is abnormal noise (B) whether the current is stable (C) whether the vibration is abnormal; 3. After use: clean up after each use. Precautions for the use of polyurethane screens Polyurethane screen plates are expensive and require a large one-time investment. If they are used and maintained improperly, they will cause premature damage.