Silica gel desiccant has become the most commonly used desiccant on the market. However, due to the different requirements of various silica gel manufacturers in terms of geographical resources, production technology, quality control, enterprise management, etc., the quality of the products they produce is different. In the absence of professional testing equipment, the product quality can only be determined by visual observation and some simple methods. These methods have also led many people into this misunderstanding.
1. About the determination of adsorption capacity and water content
For the determination of the water content of silica gel, most of the most commonly used methods for desiccant companies are as follows:
1. Put a small amount of silica gel desiccant into the water and observe the intensity of the explosion when it encounters water: the explosion is fast and the explosion effect is strong, then the product is considered to have low water content and good adsorption capacity.
Note: The water explosion rate of silica gel desiccant has no relationship with the water content and adsorption capacity of silica gel. It cannot reflect the water absorption of the desiccant very well, because the "explosion" or not is only a moment, and the level of water absorption is continuous. Facts have proved that some manufacturers deliberately produce products with good "explosive rate" whose water content reaches or exceeds 15%, and their adsorption capacity is far below the industry standard, which is completely unqualified.
2. Seal a small amount of silica gel desiccant and a small amount of color-changing silica gel together, and observe the discoloration speed of the color-changing silica gel. A slow discoloration speed proves that the water content of the product is low.
Note: This detection method is relatively scientific, but it can only explain whether the water content of the silica gel desiccant tested exceeds the color-changing silica gel. In addition, the color-changing silica gel produced by the respective manufacturers, due to the different content ratio of the added raw materials, will also cause the discoloration speed of the color-changing silica gel itself to be different. Therefore, we cannot be completely convinced by this detection method.
3. Take a small amount of silica gel desiccant and place it outdoors for 2 days after weighing. After weighing, calculate the difference between the two weighing results. If the difference is large, it is considered that the product has a good adsorption capacity. To
Note: The principle of this method is correct, but because the external environment is constantly changing, the results detected by this method cannot be completely convinced.
4. Take a small amount of silica gel desiccant and hold it firmly in your hand, and feel whether it is hot. If it is hot, it proves that its quality is good.
Note: Silica gel desiccant will release a certain amount of heat when it absorbs water, but its method is completely incorrect based on artificial feelings.
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2. About dimethyl fumarate DMF
Dimethyl fumarate DMF is an independent antifungal agent. It is an organic compound synthesized from certain chemical raw materials. It penetrates the cell membrane of microorganisms and enters the cell to exert its antibacterial effect.