A desiccant is a hygroscopic substance that induces or sustains a state of dryness in its local vicinity in any moderately well-sealed container. Perhaps the most common natural desiccant is salt, which has been used for millennia in the preparation of dried food.
Desiccant Company Links
- Delta Adsorbents has been a leading distributor of desiccant bags, humidity indicator cards and plugs, silica gels, and sorbeads for a wide variety of industries since 1969.
More on Desiccants
Most common pre-packaged desiccants are solids, which work through absorption or adsorption of liquids, or a combination of both. Specialized desiccants may be created in non-solid forms, and may work through other principles, such as the chemical bonding of water molecules. Desiccants are most commonly used to remove excess humidity that could potentially degrade or destroy products sensitive to moisture. Common chemical desiccants include silica gel, calcium sulfate, calcium chloride, and specific varieties of clay. Several different measurements can be used to determine the effectiveness of desiccant performance. The ratio of water storable in the desiccant, relative to its mass, is perhaps the most important factor. The residual relative humidity of the medium being dried is another important measure of efficiency. Desiccant performance can vary greatly with ambient temperature, relative humidity, and absolute humidity. In addition to its effectiveness at drying, desiccants may be selected for a given task based on natural antibiotic, pesticidal, fungicidal, or virucidal effects. A lack of harmful effects may also be a consideration. Desiccants are generally chemically stable and/or chemically inert. This is important as desiccants are commonly used for preservative purposes. There are no hard and fast rules for determining the ideal desiccant for a given application. The final decision on which desiccant to use, how much, and in what form is usually based on testing, practical experience, and trial and error.
