Desiccants are very common in daily life. Usually, there will be a desiccant in the nut food packaging bag. The purpose of the desiccant is to reduce the humidity of the product and prevent the product from deteriorating due to moisture, thereby affecting the quality and taste of the product. Although the function of the desiccant is to absorb the moisture of the air in the product, its use principle and material are different. There are two types according to chemistry and physics, and yltpacking will introduce these two desiccants below. 1. Chemical desiccant: 1. Calcium chloride desiccant Calcium chloride is mainly made of high-quality calcium carbonate and hydrochloric acid. It was refined by reaction synthesis, filtration, evaporation, concentration and drying. It is commonly used as calcium fortifier, chelating agent, curing agent and desiccant in the food industry. In addition, it is also used as a desiccant for gases. It can be used to dry neutral, alkaline or acidic gases, and used as a dehydrating agent in the production of ether, alcohol, acrylic resin, etc. Calcium chloride is mainly porous, granular or honeycomb material, tasteless, slightly bitter, soluble in water and colorless. 2. The main component of quicklime desiccant is calcium oxide, which can absorb water through chemical reaction, can dry neutral or alkaline gas, and is irreversible. The most common use of this desiccant is in “ice cream”. In addition, it is also commonly used in electrical appliances, leather, clothing, shoes, tea, etc., but because quicklime is a strong base, it is highly corrosive, and there are always elderly people and children whose eyes are injured because of this, so it is gradually being eliminated. 2. Physical desiccant: 1. The main component of silica gel desiccant is silicon dioxide, which is made of natural minerals into granules or beads. As a desiccant, its microporous structure has a good affinity for water molecules. The most suitable hygroscopic environment for silica gel is room temperature (20-32°C) and high humidity (60-90%), which can reduce the relative humidity of the environment to about 40%. Silica gel desiccant has the characteristics of colorless, odorless, non-toxic, stable chemical performance and good hygroscopic performance. Widely used in instruments, meters, leather, bags, food, textiles, equipment, etc. Its function is to control the relative humidity of the environment during storage and transportation to prevent moisture, mold and rust. It is worth noting that this is the only desiccant approved in the European Union. 2. The most important feature of fiber desiccant is that it is made of pure natural plant fiber and refined by special technology. It is worth mentioning that the coated fiber desiccant tablet saves space and is convenient and practical. Its moisture absorption capacity is equivalent to its own weight, much higher than other desiccants. Because of its moderate price, safety and sanitation, it is the best choice for many health care products, pharmaceuticals and biological desiccants. 3. The appearance of clay (montmorillonite) desiccant is gray spherical, which is most suitable for absorbing moisture in the environment below 50°C. If the temperature is above 50°C, the degree of “water release” of the clay is greater than the degree of “water absorption”. But clay has the advantage of being cheap. The desiccant is widely used in medical care, food packaging, optical instruments, electronic products, military products and civilian products. Due to the use of pure natural bentonite raw materials, it has the characteristics of strong adsorption, fast adsorption, colorless, non-toxic, no environmental pollution, and no contact corrosion. It has the characteristics of environmental protection, colorless, non-toxic, no harm to the human body, and good adsorption performance. Adsorption activity, static dehumidification and deodorization. The above is the whole content of “drying agent in food packaging bag”.