Fumed silica is a general term for white powdery X-ray amorphous silicic acid and silicate products. It mainly refers to precipitated silica, fumed silica, ultrafine silica gel and aerogel, and also includes Powdered synthetic aluminum silicate and calcium silicate, etc. Fumed silica is an important reinforcing raw material in the rubber industry. Because its microstructure and aggregate morphology are similar to carbon black, and have similar reinforcing properties in rubber, it is called fumed silica. According to its production method, it can be divided into two categories, namely precipitation method fumed silica and fumed silica. Precipitation method fumed silica is used as a rubber reinforcement raw material, mainly used in tires, shoes, and other light-colored rubber products.

Fumed silica (fumed silica) is one of the extremely important high-tech ultrafine inorganic new materials. Because of its small particle size, it has a large specific surface area, strong surface adsorption, large surface energy, and high chemical purity. Good dispersion performance, thermal resistance, electrical resistance and other aspects have specific performance. With its superior stability, reinforcement, thickening and thixotropy, it has unique characteristics in many disciplines and fields and has an irreplaceable role. Nano silica, commonly known as "ultra-fine fumed silica", is widely used in various industries as additives, catalyst carriers, petrochemicals, decolorants, matting agents, rubber reinforcing agents, plastic fillers, ink thickeners, metals Soft polishing agent, insulating filler, advanced daily cosmetic filler and spraying material, medicine, environmental protection and other fields. It also provides a new material foundation and technical guarantee for the development of related industrial fields.

The reinforcing effect of fumed silica mainly depends on its specific surface. Generally, with the increase of specific surface area, various strength indexes of rubber products increase, but the resilience decreases, the tear strength decreases, and it is not abrasion resistant. , Difficult to disperse during mixing, high heat generation, high Mooney viscosity, and easy to scorch. Therefore, different formulations and different uses require different specific surface areas. The effect of specific surface area on the physical and mechanical properties of vulcanized rubber is not consistent.