What Is Silica Gel?
Silica gel alias: Silicic acid gel, which is a highly active adsorption material, is an amorphous substance. The main component of silica gel is silicon dioxide, which is chemically stable and does not burn.
- Generally speaking, silica gel can be divided into
Silicone to distinguish between true and false
- In terms of feel, the toughness and elasticity of silicone products are very good, and they are not easy to be permanently deformed by external forces, and they feel smoother, while fake silicone products are easily deformed, and they are rough to the touch, There is no layer of grease on the surface of the fake silicone.
- In terms of characteristics, silicone products are non-toxic, tasteless and colorless. They have good texture and are not harmful to the human body. Generally, fake silicone products are difficult to achieve these effects. Fake and inferior silicone products are generally poisonous and pungent Yes, but also rough!
- At the same time, we can also burn real and fake silica gels through flames. It is very useful for fake silica gel products to emit black smoke and the remainder is black powder when burning. Real silica products emit white smoke regardless of the color. The combustion residue is white powder.
Silicone Silicone Adhesive
- According to different needs, you can choose the following adhesives:
- 1. KD-866: fast bonding silicone material, no surface treatment, single component, easy operation;
- 2. KD-855: It is suitable for the bonding of small-area silica gel to metal planes, facades, sockets, etc. The surface of the silica gel needs to be treated with KD-770;
- 3.KD-833: suitable for silicone, PP, PE and other difficult-to-stick plastics, fast bonding; silicone surface needs to be treated with KD-770;
- 4.G-988A: Suitable for silicone-bonded silicone, silicone-bonded glass, silicone-bonded cloth, etc., one-component room temperature vulcanized rubber. After curing, the elastomer has excellent waterproof, shockproof adhesive, high and low temperature resistance, 1-2mm If it is thick, it will begin to solidify in about 10 minutes, and will basically solidify in 5-6 hours, with a certain strength. It takes at least 24 hours to fully cure. Single component, no need to mix, just apply after standing, no need to warm.
- 5.G-988: Suitable for silicone adhesive plastic (PC, PS, ABS, etc.), silicone adhesive metal (iron, aluminum, stainless steel, zinc alloy, etc.), silicone adhesive bamboo wood, silicone adhesive stone, etc. One-component room temperature vulcanizate. After curing, the elastomer has excellent waterproof, shockproof adhesive, high and low temperature resistance. If the thickness is 1-2mm, it will be cured in about 10 minutes, and it will be cured in 5-6 hours with a certain strength. It takes at least 24 hours to fully cure. Single component, no need to mix, just apply after standing, no need to warm
Regeneration of silica gel
- I. Regeneration after silica gel absorbs water
- After the silica gel absorbs moisture, it can be removed by thermal desorption. There are various heating methods, such as electric furnace, flue heat and hot air drying. The temperature for removing the additional heat is preferably controlled at 120-180 ° C. For the blue glue indicator, color-changing silica gel, and blue silica gel, it is suitable to be controlled at 100-120 ° C. The maximum temperature for various industrial silica gel regeneration should not exceed the following limits:
- Coarse pore silica gel should not be higher than 600 ;
- Fine-pored silica gel should not be higher than 200 ;
- Blue gel indicator (or discolored silica gel) should not be higher than 120 ;
- Silicon aluminum glue must not be higher than 350 .
- After regenerating the silica gel, the moisture content is generally controlled below 2% and it can be put back into use.
- Regeneration after silica gel adsorbs organic impurities
- Sintering
- For coarse-pored silica gel, it can be gradually heated to 500-600 in a baking furnace for about 6-8 hours to
- The rubber particles can be white or tan. For fine-pored silica gel, the firing temperature cannot exceed 200 ° C.
- Rinse
- After the silica gel is saturated with saturated water vapor to reach saturation, it can be soaked and rinsed in hot water, and a combination of detergents can be used to remove waste oil or other organic impurities. After washing with water, it is dried and dehydrated.
- Solvent Rinse
- According to the type of the organic substance adsorbed by the silica gel, an appropriate solvent is selected to dissolve the organic substances adsorbed in the silica gel, and then the silica gel is heated to remove the solvent.
- Third, the issues that should be paid attention to silica gel regeneration
- When drying and regenerating, pay attention to gradually increasing the temperature, so as not to cause the rubber particles to burst due to drastic drying and reduce the recovery rate.
- When the silica gel is roasted and regenerated, excessive temperature will cause the pore structure of the silica gel to change, which will obviously reduce its adsorption effect and affect the use value. For blue gel indicator or color-changing silica gel, the temperature for desorption regeneration should not exceed 120 ° C, otherwise the color development effect will be lost due to the gradual oxidation of the color developer.
- Regenerated silica gel should generally be sieved to remove fine particles to make the particles uniform.
- Storage and packaging
- Silicone has a strong ability to absorb moisture, so it should be stored in a dry place with a shelf between the packaging and the ground. Packaging materials include steel barrels, paper barrels, cartons, plastic bottles, polyethylene plastic composite bags, flexible container bags, and so on. Avoid rain, moisture and exposure during transportation.
Silicone performance comparison
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- The superior performance, coupled with the fact that silica gel is a non-petroleum product, does not rely on increasingly scarce petroleum resources, makes silica gel products a substitute for similar plastic products. It is a general trend, and silicone products can be applied to many applications where plastic products cannot. Such as baby pacifiers, the application prospect is very broad. All silicone products can pass the US FDA certification, SGS certification and European LFGB certification to achieve barrier-free market entry. It has been professional and meticulous in silicone daily necessities, silicone promotional gifts, and jewelry. It has complete and mature product design, molding, production, and domestic / international market supply chains. Its products are in large shopping malls such as Rainbow, Junshang, and China Resources Vanguard Sales, covering more than 60 stores, the foreign trade is exported to the United States, Britain, Germany, Russia, the Netherlands, Spain, Australia, Denmark, Italy, Hungary, Switzerland, Sweden, Hong Kong and other countries and regions, and has been widely recognized and praised by consumers. . Silicone daily necessities have become a beautiful landscape of people's fashion life. [6]