Aktifit is an activated Silfit Z 91 produced by modifying the surface with functional silanes. The by-products split off during the treatment reaction are largely removed during the production process which firmly attaches the silane to the filler surface. This helps minimize undesirable side effects, as they are potentially encountered with in-situ mixing (direct addition of silane to the compound).

All calzined products have a particle size that approaches that of the uncalcined basic material Sillitin Z 86.

The measuring method for this particle size distribution is based on the Fraunhofer analysis of diffraction spectra. The analyses were performed with a Mastersizer 3000, which is a laser device from Malvern Instruments.

With regard to the CIELAB color values L*, a* and in particular b*, the calcined products are significantly brighter and more color neutral than the classic products Sillitin and Aktisil.