There are two kinds of silica gel: one is precipitation silica gel; One is fumed silica gel. Fumed silica gel is resistant to high and low temperature impact, the release during vulcanization is harmless to the human body, bonding with a variety of substrates without the use of primer, and has excellent heat resistance, ozone resistance and chemical attack resistance. Fumed silicone also has excellent electrical insulation properties. So what is the difference between precipitation silica gel and fumed silica gel?



The difference between fumed silicone rubber products and precipitation silicone rubber products:

1. The silica gel products of the precipitation method will be whitish when stretched, and the elongation rate is not good, while the silicone products of the gas phase method are different, they will not be whitish when stretched, and the elongation at break can reach more than 700%.

2. The raw material cost of fumed silicone products is higher than that of precipitation silicone products, and the tensile strength, tear strength and tear elongation of fumed silicone rubber products are better than those of precipitated silicone rubber products under the same hardness, and its environmental protection index is also higher.

3. The appearance of fumed silicone products is transparent. The appearance of precipitation silicone products is opaque or translucent.

4. The gas phase method is produced by using silicon tetrachloride and silica obtained by air combustion, with a fineness of more than 1000 mesh, and the precipitation method is produced by using silica precipitated by adding sulfuric acid to sodium silicate. The fineness is only 300-400 mesh.

5. The fumed silica contained in fumed silicone rubber is expensive and not easy to absorb moisture, and it is mainly used for reinforcing in rubber. The silica in precipitated silicone rubber is inexpensive and easily hygroscopic. In rubber, it is mainly filling.

pls check General Purpose Fumed Extrusion Silicone Rubber