After wearing it once (not for too long), although you can continue to use it next time, you should not take the cumulative length of wear as the only criterion for changing to a new one, but should consider the cleanliness of the mask itself. In addition, it is recommended that masks worn in inter-regional public transportation, places where people gather, hospitals and other environments are not recommended for repeated use.

If you need to take off the mask outside, you should not put it into your coat pocket for storage. If you buy a single packaged mask, you can keep the original packaged bag and store it in the original packaged bag after taking off the mask by folding it (inside of the mask facing inward); if you use multiple packaged masks together, you should have a cleaning bag with you and store it in the cleaning bag after taking off the mask. If you do not have a cleaning bag, you can use two paper towels: first lay a paper towel flat, put the mask on it (note that the outside of the mask is down), and then cover it with a paper towel. This will keep the inside of the mask clean and prevent contamination from the mask being placed in your coat pocket, and ensure that it does not become deformed.

Usually look at the price of machinery, quality, what you pay for.There are 30,40,40,50,60 and above.Very bad machinery a minute production of 20 or 40 or 50 more is even good.The rated speed is different from the actual speed, but also depends on the master's adjustment level, the quality of the raw material and the operation status of the equipment.