Desiccant: practical protection from humidity
A desiccant is a hydrating agent which attracts moisture from the atmosphere. It adsorbs and holds particles of water to itself. To be used most effectively, desiccants should be used within a closed/sealed moisture barrier, or a rigid/sealed container.
According to DIN 55 473 and MIL-D3464 with the use of desiccant the following aim are achieved: Desiccant consists of a water vapor permeable outer material e.g. paper, non-woven or Tyvek. Bentonite (dry clay) or silica gel are mainly used as absorbing media (desiccant). Task of the desiccant is to absorb the humidity within the resistive layer bag and to lower it, to exclude the danger of corrosion. The desiccants are handled in so called desiccant units.
According to DIN 55 473, the dried bentonite can absorb about six grams of water vapor at a relative humidity of 40%. In order to create appropriate conditions inside the packaging, and therefore to protect your shipment from corrosion, the following steps are needed to properly calculate » to properly calculate the quantity of desiccant required.
Placement of the desiccant bags
To avoid the accumulation of condensed water, the bag of drying agent should be placed in the upper region of the protective packaging, because the warm, moist air rises upwards.
To achieve the longest possible period of protection, the barrier envelope should be welded immediately after inserting the desiccants. Make sure at this stage that only about 70% of the enclosed air is drawn out, so that the air can circulate adequately.
