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There will be several "small holes" on the top of the coffee pouch bags, so what is the mystery of the coffee pouch bags?

Time:2023-06-09 Views:


Friends who often buy coffee beans will find that the structure of the coffee packaging bag is very special. There are several "small holes" on the top of the bag. So what is the mystery of the coffee packaging bags?

In fact, these "small holes" have a name called [one-way exhaust valve]. As the name suggests, it allows the air on one side to move to the other side, while blocking the air on the other side from entering this side.


Because when the coffee is freshly roasted, it can be packaged in bags after cooling down to normal temperature. While the coffee is in a very fresh state, the coffee beans will slowly emit carbon dioxide. And if it is completely sealed, the packaging bag will be expanded by the gas and burst.

So a valve is needed to discharge the gas inside and block the outside air from entering. When the carbon dioxide gas produced by the coffee beans sealed in the bag reaches a certain pressure in the bag, the gas can push the exhaust valve sheet from the inside to the outside to discharge excess gas to the outside.


When the pressure in the bag is reduced enough to open the valve, the valve is automatically closed. And only when the pressure inside the bag is higher than the pressure outside the bag, the valve will automatically open, otherwise it will not open, and the outside air cannot enter the bag. Sometimes, the release of a large amount of carbon dioxide may burst the packaging of coffee beans, and the coffee degassing valve produced by Wojin can prevent this from happening.

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