Liquid silicone rubber is divided into two types: gas-phase silicone rubber and precipitated silicone rubber. There are certain differences in the production process, product performance, and application scope of these two types of silicone rubber. The following will give you an in-depth understanding of the differences between gas-phase silicone rubber and precipitated silicone rubber.

1. Production process

The gas phase production method uses silica obtained by burning silicon tetrachloride and air, with a fineness of more than 1000 mesh. The precipitation method production uses sodium silicate, adding sulfuric acid to precipitate the silica, and the fineness is only 300-400 mesh. Head.

The silica produced by fumed silica is expensive and not easy to absorb moisture. Used as matting agent in paint. Precipitated silica is cheap and easy to absorb moisture. It can only be used for filling and reinforcing rubber and plastic products.

2. Product performance

The liquid silicone rubber of the precipitation method will turn white when stretched, and cannot be stretched very long, but the gas phase silicone rubber is different. The gas phase silicone rubber will not turn white no matter how it is stretched, and it can be stretched for a long time without breaking. Good gas-phase silicone rubber can be stretched to more than 700%, and the transparency of gas-phase silicone rubber is higher than that of precipitated silicone rubber.

The tear strength and elongation rate of silicone rubber reinforced with fumed silica are better than those reinforced with precipitation silica. Transparency in vapor phase. Opaque or translucent by precipitation method.

The cost of silicone rubber produced by the gas phase silicone rubber is higher than that of the precipitation silicone rubber. Therefore, the tensile elongation of gas phase silicone rubber with the same hardness is better than that of precipitation silicone rubber, and its environmental protection index is also higher. Vapor-phase silicone rubber is generally an addition-type 10:1 transparent silicone rubber, and precipitated silicone rubber is generally an addition-type 1:1 translucent silicone rubber.

3. Scope of use

Vapor-phase silicone rubber has better tear resistance and is suitable for: products inside covers, pressure cooker rings, silicone wires, etc.; precipitation silicone rubber has a better impact life and is suitable for: remote control buttons, mobile phone buttons, foot pads, etc.