Pyrogenic silicas are fumed salicium dioxide and are obtained by chemical means, for which sand is taken as a starting material. The substances are always similar in color and form – white, odorless powder with a pH of 3.7 – 4.7 at a temperature of 20 °C, but each type has its own advantages and characteristics. This powder has a very low density and a large surface area, which is why he is used as a filler.
Fumed silica can be used in a wide range of applications. They are frequently used as anti-blocking and coating agents. Furthermore, they are also used in large parts in the field of paints and varnishes. Otherwise, they also serve sometimes as reinforcing agents as well as carriers.