SiVARA™ is the recipient of the recent Frost and Sullivan European Technology Innovation award for changing the paradigm of glass manufacturing with its SiVARA™ process at the start of the century.In very general terms sol-gel manufacturing process represents an alternative to currently used methods for producing silica glass. The SiVARA™ process is based on a special sol-gel process that facilitates the processing of fine powders such as AEROSIL®, as well as AERODISP® dispersions, into compact glass-mold bodies free of cracks. AEROSIL®, a fumed silica is the basic raw material of the SiVARA™ process. AEROSIL® forms, with other components, a colloidal suspension of silica particles known as sol inside the reactor. That suspension is then poured in the mold where it gels and forms a silica network is then dried. Upon drying, a xerogel is obtained which is then withdrawn from the mold and sent into a furnace. Here, it is subjected to the final stages of chemical purification to obtain a silica product that demonstrates high purity levels, which result in very good optical transparency over a broad electromagnetic spectrum ranging from ultraviolet to infrared light.

Previous attempts to manufacture silica glass using sol-gel routes failed because the silica glass produced was subject to breakage. Evonik Degussa GmbH has been able to overcome this obstacle and achieve very high geometric reproducibility of its glass objects. It has accomplished this through leveraging the principle of molding and gelling of liquids at room temperature. In fact, by using the SiVARA™ technology it is possible to predict the final dimensions of an object with a precision of 2/3 over 1,000. This high accuracy meets the requirements of many high-end applications. Such level of precision is reachable by conventional techniques only after expensive after-treatments.

Vis-à-vis conventional techniques, the objects produced via SiVARA™ do not need after- treatments such as cutting, polishing, or grinding. Further, current techniques for the manufacturing of quartz objects are based on the melting of the raw materials and the pouring of the melt (> 1,700 degrees C) in molds. This provides a significant amount of freedom in terms of shape-design and material used for molds. As an example, plastics can be the raw materials for molds for the manufacture of very sophisticated quartz objects; the same objects are affordable by conventional techniques only with very expensive equipment and treatment. Other key benefits provided by the SiVARA™ technology include the production of a silica glass, which does not foam or produce bubbles when the material is subject to temperatures in excess of more than 1,700 degrees C. The process also enables modification of the sol composition to produce glasses doped in a homogeneous manner for high tech applications.