Desiccant is actually very common in daily life. Usually, there is a desiccant in the food bag of some nuts, and the function of the desiccant is to reduce the humidity of the product and prevent the product from being damaged by moisture, thus affecting the quality and taste of the product. . Although the function of the desiccant is to absorb the humidity of the air in the product, the principle of use and the material are different. They are divided into two categories according to chemistry and physics: composite packaging bags, aluminum foil bags, and plastic packaging bags. Chemical desiccant: 1. Chlorinated Calcium desiccant Calcium chloride is mainly made of high-quality calcium carbonate and hydrochloric acid as raw materials, which are refined through reaction synthesis, filtration, evaporation concentration, drying and other processes. . In addition, it is also used as a desiccant for gases, which can dry neutral, alkaline or acidic gases, and is used as a dehydrating agent for the production of ethers, alcohols, propylene resins, etc. Calcium chloride is mostly porous block, granular or honeycomb raw material, odorless, slightly bitter taste, soluble in water and colorless. 2. Quicklime desiccant The main component is calcium oxide, which absorbs water through chemical reaction, can dry neutral or alkaline gas, and is irreversible. The most common is the use of such desiccants in “snow cakes”. In addition, it is also often used in electrical appliances, leather, clothing, shoes, tea, etc., but because quicklime is a strong alkali, it is very corrosive, and the eyes of the elderly and children are sometimes injured. eliminated. Physical desiccant: 1. Silica gel desiccant The main component is silicon dioxide, which is granulated or beaded from natural minerals after purification and processing. 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℃) and high humidity (60~90%), which can reduce the relative humidity of the environment to about 40%. Silica gel desiccant is colorless, odorless, non-toxic, chemically stable, and has good hygroscopic performance. Widely used in meters, instruments, leather, luggage, food, textiles, equipment and equipment. Its function is to control the relative humidity of the environment during storage and transportation to prevent items from being damp, mildewed and rusted. It is worth noting that this is the only desiccant approved in the EU. 2. Fiber desiccant The biggest feature is that it is made of pure natural plant fiber, which is refined through a special process. It is worth mentioning that the film-coated fiber desiccant sheet is space-saving, convenient and practical, and its moisture absorption capacity is comparable to its own weight, much higher than that of other desiccants. Due to its moderate price, safety and hygiene, it is the best choice for many health products, medicines and biological desiccants. 3. Clay (montmorillonite) desiccant Appearance shape as a gray ball, most suitable for moisture absorption in the environment below 50 ℃. If the temperature is higher than 50°C, the degree of “water release” of the clay is greater than the degree of “water absorption”. But the advantage of clay is that it is cheap. , The desiccant is widely used in medical care, food packaging, optical instruments, electronic products, military products and civilian products. Because the pure natural raw material bentonite is used, it has the characteristics of strong adsorption force, fast adsorption speed, colorless and non-toxic, no environmental pollution, no contact corrosion, green environmental protection, colorless and non-toxic, no damage to the human body, and good adsorption performance. Adsorption activity, static dehumidification and odor removal.
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