Desiccants are often divided into chemical desiccants and physical desiccants. The main components of chemical desiccant are calcium sulfate and calcium chloride, which are combined with water to form hydrate for drying; Physical desiccant, mainly composed of silica gel and activated alumina, is dried by physically adsorbing water.
The control of moisture is closely related to the yield of products. In the case of food, under appropriate temperature and humidity, bacteria and molds in food will multiply at an alarming rate, causing food decay, moisture and color change.
Electronic products will also cause metal oxidation due to high humidity, resulting in defective products. The use of desiccant is to avoid the occurrence of defective products caused by excess water.
Desiccants in food are generally non-toxic, tasteless, non-contact corrosive and no environmental pollution. Food desiccants are generally packaged in boxes. The powder in food desiccants is harmful to eyes or other parts of the body, which is very destructive to the cornea, so we'd better not contact the powder inside; Laboratory desiccants such as concentrated sulfuric acid, alkali lime and so on are too dangerous, but they also have advantages, such as fast water absorption, high efficiency, low price and so on.