The main reason for the black spots on the sealing ring of the lunch box is that it has been used for a long time and improperly cleaned. If the black spots on the seal ring cannot be washed off, the following methods can be tried:
1. Use bleaching water to clean: after removing the seal ring, soak the seal ring with diluted bleaching water for about 10 minutes. Then rinse it with clean water and dry it.
2. Use vinegar water for cleaning: after removing the seal ring, soak the seal ring in diluted vinegar water for about 10 minutes. Then rinse it with clean water and dry it.
3. Cleaning with toothpaste: after taking off the seal ring, apply a little toothpaste on the seal ring, gently brush it with a brush, then rinse it with clean water and dry it in the air.
4. Replace the seal ring: if the black spots on the seal ring cannot be cleaned by the above methods, it is recommended to replace the seal ring with a new one.
In short, the sealing ring is an important part of the lunch box, which needs to be cleaned and replaced frequently to ensure the tightness and hygiene of the lunch box.
