Item name: coffee bags with valve Material recommendation: PET/ AL/ PE Material density: 80-120μ( personalized). The coffee bags with valve is additionally called coffee air valve bag . The content of this coffee bag with shutoff is "coffee beans". After roasting, the coffee beans will certainly continue to give off carbon dioxide gas for a long period of time and the volume is also fairly huge. If you make use of a packaging bag with a strong sealing performance, these co2 gases can not be discharged, and also the phenomenon of bursting will occur. The coffee bags with valve are more conducive to the discharge of these gases. However, in order to preserve the dryness as well as taste, the coffee beans still require to be blocked from the outside oxygen. Will it leakage, if the bag mounted such a shutoff? It belongs to the particularity of this "exhaust valve". The air valve set up on the coffee bag is also called a "one-way air vent shutoff", The gas can ...