The reasons for the loss of vacuum degree of vacuum packaging bags are as follows: 1, The barrier property of the material is not enough. 2, There are tiny cracks that are not fully sealed on the seam edge. 3, pierced by the contents, or pierced by the edges and corners of the adjacent packaging bags, the crystal points on the material destroy the barrier layer material. 4, The material has poor flex resistance. 5, The gas produced by the fermentation of the content reduces the vacuum degree.