one way exhaust valve is a functional packaging accessory. As long as there is an exhaust valve on the packaging bag, when the gas in the bag reaches the opening pressure of the exhaust valve, the excess gas in the bag can be automatically discharged, and the outside air is blocked from entering the bag to prevent the inner packaging from being oxidized and contaminated. The exhaust valve with a filter screen filters the powder in the packaging bag to prevent the powder from spraying out of the bag and causing pollution.
