A desiccant, simply put, is a material that is used to maintain or stimulate a state of desiccation near its vicinity; in layman’s terms, it’s the opposite of a humidifier. Most commonly found in pre-packaged moist desiccants is solid materials which absorb liquid water from surrounding atmosphere. Some common materials include salt crystals, sand, and seaweed. In some cases, a moisture desiccant may be in the form of a plastic bag, but is usually made of an inert gel or liquid substance. This liquid substance will absorb moisture from the air before being returned to the atmosphere; in this case, the product is called a dehumidifier. These products work by keeping the surrounding environment at a constant, lower temperature, and as such, a higher humidity level is maintained in the surroundings. In doing so, water can be allowed to evaporate from the surroundings; this process is what causes the moisture to evaporate, allowing moisture vapor to rise into the air, making the surroundings humid again.
A desiccant comes in various applications and can be employed in various different environments. Examples of the different desiccant types that can be used in a variety of applications include polyethylene (PE), polypropylene (PP), polystyrene (PS), carbon black, sodium chloride, and salt crystals. PE is most commonly used in the food industry for a wide variety of purposes including as an absorbent material, as a protective covering for packaging materials, and as a lubricant. However, PE can also be useful as a dehumidifier, which uses the material as a temporary moisture absorber. Other possible applications of PE include as a non-porous insulation layer, and in some cases as a thermal reflective foil material that will reduce or eliminate heat transfer when heated; this property makes the material an excellent absorber for heat and radiation.
The benefits of using a desiccant in a variety of applications are numerous and include, but are not limited to, reducing condensation, evaporation, humidity, and water vapor buildup. Other potential benefits include the reduction of condensation in residential and commercial buildings; it also eliminates condensation build up by providing a damp barrier between the interior and exterior of the building. and reduces moisture accumulation in roof tiles, siding, insulation, pipes, and the interiors of appliances. Other applications include air conditioning, cooling, air quality control, and as a humidity regulator.