Therefore, if conditions permit, we suggest to use barrier materials with good barrier properties (that is, low water vapor permeability) to package products. In addition, the seal of the barrier package must be tight, and there must be no air holes. Any tiny air leakage hole will greatly reduce the effectiveness of the desiccant.

Under different temperature and humidity conditions, the water vapor permeability of the same barrier material is also different. The higher the temperature and humidity, the higher the water vapor permeability. But when we calculate, we can only use an average value. DIN55474 is the value that suggests that we use the water vapor permeability at 23℃ and 85% RH. The calculation will be more accurate if the value is taken in combination with the actual situation.

3. Three sources of moisture in packaging

In a specific package, there are three sources of moisture, and the mission of desiccant is to absorb these three parts of water vapor and control the humidity in the package below the target humidity.