How to distinguish between true and false silica gel?


2020/12/3 14:03:36



Daily use of silicone gradually began to cover our lives, but it has become a difficult problem to buy a regular and high-quality product. Everyone knows that there are people in any industry who make fake and inferior products, and there are similar situations in the silicone industry. However, in the silicone products industry, silicone rubber materials are actually partly true and false, because even if they are distinguished from each other, it is just that there are different components in the material that lead to deterioration of performance. What consumers and friends need to distinguish is its advantages and disadvantages. Which material belongs to the first-class goods and which one belongs to it.


Conventional methods to identify the quality of silica gel products are as follows:

1. weight test: the density of silicone rubber product is 1.3, so high-precision instruments are needed for analysis, and the weight of the product is accurate to about 0.01g, which can be identified by means of materials, because the materials normally added in silicone rubber are silane coupling agent, silicone oil, white carbon black, silicone resin and other curing agents and color glue during mixing, and if there are errors in the quality of compounds in silicone rubber, there are subtle differences in weight, so the same products can be used for accurate test.


2. Soak test, calculate the shrinkage rate of silicone products. Generally, the shrinkage rate of silicone products is 0.0012-0.0013. After sampling, measure the size by secondary dimension, then soak the products in liquid for 20 hours, and take them out to see if there is any obvious dimensional change in silicone products. The data size of general production should be accurate to 0.1 mm. After the test, you should pay attention to the fact that the shrunk silicone rubber material becomes heavier after soaking and wading or the size foaming increases.


3. Temperature test is the most intuitive. Both high temperature and low temperature can test the quality of silica gel products. In the high temperature test, ordinary silicone rubber products are put at about 280℃ for ten minutes. If the silicone rubber products after taking out have no change, the quality of the products can be trusted and the temperature resistance can be achieved. If the taken-out products are deformed, the latter will be aged or even burnt locally, then there will be some problems with the compound additives in the products. Test at low temperature and put it in a suitable low temperature environment. Soak the sample in a low temperature environment for 2-5 minutes, and feel the softness and hardness at the selected temperature. For example, at -40℃, the softness of high-quality silica gel will be softer when compared with silica gel products with good high temperature and oil resistance.


4. Combustion method: The most effective method is also the method that can best reflect the true and false silica gel. Generally, high-quality silica gel products are different from other rubber materials after burning, and will emit white smoke. After burning, the surface of the products will appear white mist, which will be white powder after completely burning, completely colorless and tasteless, while different materials will turn yellow, and the rubber materials will burn out, with black residue and so on.


5. Color test: Silicone rubber products can be blended with different colors according to the international Pan Tong color number, so there is no difference in color at all and there is no flaw after appearance treatment, but the main thing is whether the rebound will appear white or transparent after stretching. If there is one, the material may belong to ordinary material!


6. Hand feeling test: Hand feeling is very important. Silicone products are very important in terms of stretching, springback, deformation and toughness. If the above properties are achieved, they can basically be regarded as high-quality materials.





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