Silica Gel Desiccant is widely used in food moisture
Food packaging often see food waste desiccant figure, if careful friends will find some of the same desiccant. Some desiccants are brightly colored, some are white irregular blocks, and some are brown beads. The composition of the different desiccant is completely different. There are three common types of food desiccant: silica gel desiccant (bright particles), lime desiccant (white block), mineral desiccant (brown ball).
There are two kinds of discoloration silica gel desiccant, one is orange silica gel desiccant, one is blue silica gel desiccant. Orange silica gel desiccant attributed to non-toxic products, and blue silica gel desiccant because with "cobalt chloride", cobalt chloride has a strong toxicity, the water vapor in the air has a strong adsorption effect, together with the The amount of crystal water containing cobalt chloride changes to show different colors, that is, by the moisture before the blue with the addition of moisture gradually into light red.
Orange silicone, also known as "cobalt-free color silica gel", is an environmentally friendly desiccant, attributed to the silicone products. Appearance is orange or semi-transparent glassy particles. With a strong moisture absorption and in the process of moisture absorption of its appearance will follow the addition of moisture absorption and a significant color change. Is it possible to use it for food? As long as the orange silica gel desiccant is suitable for moisture-proofing of food desiccants, the commercially available Silica Gel Desiccant is now available on the market, although it is not safe.
Silica Gel Desiccant is a highly active adsorbent material, the chemical nature of inactive, generally only and sodium silicate and sulfuric acid reaction, aging, acid bubble and other processes eventually worth it. The chemical formula of silica gel mSiO2. NH2O, amorphous substances, insoluble in water and any other volume, chemical stability, non-toxic and tasteless, in addition to alkali and hydrofluoric acid, generally do not react with other substances. The chemical and physical properties of silica gel determine the desiccant material of its kind is difficult to replace. Such as: stable chemical properties, strong mechanical properties, good thermal stability, good adsorption.
Silica Gel Desiccant are divided into: fine silica gel, B type silicone, macroporous silica gel, coarse silica gel, etc., because their adsorption gap is not the same, so their adsorption characteristics are different. Porous silica gel is for the relatively low humidity conditions, the adsorption capacity is higher than the coarse control regulation, two relatively high humidity environment environment, the characteristics of coarse control system than the characteristics of fine pore silica gel is much better.
B-type silica gel is generally between the coarse and small silica gel, the amount of adsorption is also between the two. Loose silica gel is generally used in the catalyst carrier, matting agent, toothpaste abrasive raw materials, according to the specific use of different, for the above silica gel desiccant for more detailed use.
How to identify the silica gel desiccant failure, what is the simple self-test method? Have the following simple methods for your reference:
1) the Silica Gel Desiccant bag tear, take silica gel silicone material grip hands to see if there is heat, heat is that silica gel desiccant is also effective.
2) If you add blue plastic, orange indicator, indicating that glue has changed color, indicating that silica has failed.
3) small cup of cold water, tearing the desiccant bag, the raw materials into the water to see if the silicone particles will be broken into pieces, and issued a "Cha Cha" sound, is effective.
4) take a small bag of Silica Gel Desiccant, said good weight, good mark, placed indoors, every 5-10 days and then weighing, to see whether there will be weight increase, there is an increase is effective.
5) To understand the precise moisture absorption performance of silica gel desiccant, use laboratory equipment to detect.