Calcium chloride (CaCl2) is a white powder, granule, flake, or block. Due to its certain characteristics of calcium ions, it can combine with some water to form crystal water CaCl2·nH2O, n=1,2,4,6 Calcium chloride (CaCl2) has a high solubility in water. 100 °g of water can dissolve 59.5 g of calcium chloride at 0 ° C, and 100 g of water can dissolve 159 g of calcium chloride at 100 ° C. It can form hydrates containing 1, 2, 4, and 6 crystal waters, and their temperature ranges are: CaCl2•6H2O is lower than 29°C; CaCl2•4H2O, 29-45°C; CaCl2•2H2O, 45-175°C; CaCl2•H2O, above 200 °C.
Therefore: the principle of calcium chloride desiccant hygroscopic gel is that the calcium chloride desiccant chemically reacts with water to form hydrated calcium chloride, and the hydrated calcium chloride is in a liquid form. However, as a desiccant, calcium chloride needs to solidify its liquid to prevent liquid leakage. Therefore, it is necessary to add a thickener such as starch, so that the calcium chloride desiccant can be absorbed into a liquid hydrate. The substance solidifies and becomes gelatinous.