The function of metal cover 1. Protection: The metal cover can effectively protect the items in the container from the external environment, such as preventing dust, pollutants, bacteria, etc. from entering the container, and keeping the items dry, clean and hygienic. 2. Sealing effect: Metal lids can provide better sealing performance to prevent the contents of the container from leaking or external substances from entering, and maintain the original quality and characteristics of the items, such as the freshness and effectiveness of food, medicine, etc. 3. Preservation effect: The metal cover can effectively isolate air and moisture, prevent oxidation and deterioration of items, extend the shelf life of items, and maintain their freshness and taste. 4. Safety function: Metal lids can provide certain protection and safety performance to prevent items in the container from being accidentally opened or contaminated, ensuring the health and safety of users.…