Regarding the types of silica gel

The most basic way is to classify them into several major categories based on specific surface area! For example, precipitated silica: Category A refers to those with a specific surface area of over 191; Category B includes those with a specific surface area of 190–161. There are thirty samples in each category, while those with a specific surface area of less than 50 fall into another category. Gas-phase silica: For instance, A380 denotes silica with a specific surface area of 380. Of course, there are also products that have been modified and those that have not had their names changed; for example, the precipitated type: HV is a modified version. The gas-phase type: R971 is also modified. I’m not entirely familiar with the detailed classification rules, but that’s all I know.

Is the silica industry not yet saturated either?

Vapor-phase silica is mainly controlled by companies such as Wacker in Germany and Tokuyama in Japan. Currently, as the production of silicon tetrachloride as a by-product of the polysilicon industry increases significantly, the demand for this product is rising as well. The Wacker plant in Zhangjiagang and the Tokuyama plant in Zhejiang are both producing large quantities of it, achieving good profits and strong market performance. Our country does not have many manufacturing technologies; currently, the only company engaged in industrial production is Guangzhou Jibisheng, with facilities established in Jihua, Leshan and other places. However, it is said that the quality of its products is somewhat inferior to that of top foreign companies, resulting in a limited market.

Precipitated silica is also known as hydrated silica; its silica content ranges from 0.87 to 0.95, its whiteness is around 95%, the average particle size is 11–100 nm, the specific surface area is 45–380 m2·g-1, and its DBP absorption value is 1.60–2.40 cm3·g-1. 90% of silica is produced by the precipitation method, as silica obtained through the vapor phase method is expensive; therefore, the rubber industry primarily uses silica produced by this precipitation method. Precipitated silica can be used in NR and sR to manufacture tires, rubber shoes, hoses, tapes, heat-resistant gaskets, medical products, and various other colored or white rubber products. Vapor-phase silica is also known as anhydrous silica; it is a high-purity, ultra-fine form of silica with a silica content of over 0.998. Its average particle size ranges from 8 to 19 nm, the specific surface area is 130–480 m2·g-1, and its DBP absorption value is 1.50–2.00 cm3·g-1. Compared with precipitated silica, it results in a rubber compound with higher viscosity, as well as better hardness, tensile strength, stress at fixed extension, elongation at break, tear strength for the vulcanized rubber, and greater transparency of the compound. Vapor-phase silica is suitable for reinforcing silicone rubber. Silicone rubber possesses excellent properties such as aging resistance, tolerance to high and low temperatures, and electrical insulation. However, it is a linear organic siloxane with a high relative molecular mass; its molecular chains are very flexible and the intermolecular forces between them are weak, resulting in extremely low strength in the vulcanized material, which renders it unusable. It must be reinforced in order to be utilized. The physical properties of silicone rubber reinforced with fumed silica via the vapor phase method are significantly improved; its tensile strength can increase by about 20 times, and its tear strength can increase by about 40 times. This meets the requirements for reinforcing silicone rubber as well as preventing the formation of bubbles during post-vulcanization. Vapor-phase silica has a high price, so it is mainly used in silicone rubber; it can also be employed in the production of V-belts, rubber rollers, hoses, cables, oil seals, and foam products.

Our factory produces silica gel using the vapor phase method, with technology imported from Ukraine, but there are still quite a few problems in the production process!

What the people upstairs said is all quite good. Vapor-phase silica is mainly divided into two categories based on its properties: 1. hydrophobic silica and 2. hydrophilic silica. Based on their hydrophilic or hydrophobic nature, they are further classified according to their specific surface area, indicated by numbers such as 200, 380, etc. Colleagues who need and are willing to share experiences regarding silica gel can add me on WeChat at 13620082581 :)

Thank you for sharing; the forum is even better with you here.

Thank you for sharing; the forum is even better with you here.