What is a Desiccant?
- A dehydrating agent that attracts moisture from the atmosphere that “absorbs and holds” particles of water to itself.
- Desiccants are non-toxic, odorless and non-corrosive.
- Desiccants are most commonly used to prevent rust, corrosion and the formation of mold and mildew.
Most Common Desiccants:
Montmorillonite Clay: an inexpensive natural adsorbent that can be regenerated at very low temperatures for repeated use. Clay is considered to have a “moderate” absorption rate and is capable of adsorbing 30% of its weight in water vapor at 100% humidity
Silica Gel: a form of silica manufactured from sodium silicate and sulfuric acid that is non-hazardous and can also be regenerated at very low temperatures for repeated use. Silica Gel is considered to have a “moderate” absorption rate and is capable of adsorbing 40% of its weight in water vapor at 100% humidity. Silica Gel has the highest moisture adsorption capacity of any commercial desiccant.
Indicating Silica Gel: has the same adsorbing capacities of regular silica gel, however, indicating silica gel changes colors, giving visual notification to users that it is reaching adsorption capacity.
Molecular Sieve: is a manufactured form of Zeolite made from sodium potassium or calcium alumina silicate. Molecular Sieve is considered to have the “fastest” absorption rate of the primary desiccants and is capable of adsorbing 20% of its weight in water vapor at 100% humidity.
Carbon: While carbon does not absorb moisture, it is commonly packaged for use as an effective odor remover. Carbon can be packaged alone or blended with one of the desiccants listed above to absorb odor and moisture in the same package.
Most Common Substrates (outer pouch/packaging material):
- Tyvek®: FDA approved for direct food contact and meets Military Spec MIL-D-3464 Type I & II. Non-dusting, extremely strong and hard to tear or puncture.
- Kraft Paper: Meets Military Spec MIL-D-3464 Type I & II.
- Sewn Bags: Rayon/Polyester cloth bags with Tie Strings most commonly used for the larger 8, 16, 32 and 80 Unit sizes.
- Clear View (Perforated Polypropylene): Available only in PillowPaks and allows for easy viewing of indicating silica gel changing colors signaling saturation and replacement.