It is important to understand that when using a barrier foil bag for protection of products from moisture damage, a calculated amount of desiccant must be used inside the bag to absorb any existing water vapour and to neutralise the small amounts of water vapour which pass through the barrier foil.
The amount of desiccant needed to keep the foil bag dry depends upon the shipment destination (tropical or temperate), the area of the bag in square metres and the number of months the product is to be kept in the foil bag.
We can advise our customers on the most appropriate size and quantity of desiccant for the barrier foil application in line with BS1133, section 19.
We can also supply desiccant ready fitted into our foil bags and liners; our internal reference for this is “progel”.
We can also fit an humidity indicator into a foil bag to monitor the bag contents and the effectiveness of the aluminium barrier foil bag and desiccant at protecting your products against moisture ingress. Indicators can be integrated into the bag to continually monitor the relative humidity.
We can fit the sophisticated screw in indicator or a humidity card behind a clear window. A blue coloration to the card indicates the relative humidity is below the critical level and therefore corrosion has not taken place.