Silica gel is silicon dioxide (SiO2 ). It is a naturally occurring mineral that is purified and processed into either granular or beaded form. As a desiccant, it has an average pore size of 24 angstroms and has a strong affinity for moisture molecules. The silica gel will pull in moisture at temperatures up to 220°F (105°C). As temperatures goes above 100°F, the rate of moisture pickup will slow down but the silica gel will still work.
Silica gel performs best at room temperatures (70° to 90°F) and high humidity (60% to 90% RH) and will drop the relative humidity in a container down to around 40% RH. In the United States, silica gel is commonly used in food and pharmaceutical applications as only silica gel has been approved by the FDA for direct contact with these items.
As with clay, silica gel, with its wide range of pore sizes, has the capability of absorbing compounds other than water. The relative order of absorbability is: water, ammonia, alcohols, aromatics, diolefins, olefins and paraffins. When the potential for multicomponent absorption is present, expect the more strongly absorbed compounds, such as water, to displace the more weakly held ones.
|Silica gel||Bag size||Packaging||SR|
|10g||20X35MM||800BAGS/CTN||SR <= 10|
|20g||98X58MM||400BAGS/CTN||SR <= 10|
|30g||135X60MM||250BAGS/CTN||SR <= 10|
|50g||120X100MM||200BAGS/CTN||SR <= 10|