Today, the latest techniques permit the manufacture of filler with a diameter of less than a micro-meter (10-100 nanometers). The individual particles on the surface must be coated in this process, since particles of this extremely small size clump to the larger aggregates (agglomeration), if they are not coated.
These agglomerates physically behave like micro-fillers. An increase in the filler content of a composite with micro-fillers always leads to an increase in the viscosity. The filler percentage thus cannot be increased at will - the material would be too hard to be processed.
Non-agglomerated nano-particles behave, on the contrary, rather like a liquid, so that the higher filler content is not accompanied by an increase in viscosity. Only in this way is it possible to make a composite with ca. 90% filler content. Grandio Flow, the flowable composite with a filler content of over 80%, would not be possible without the use of nanotechnology. By coating the surface of the nano-particles, they crosslink with the resin to a high degree during polymerisation; this increased crosslinking in combination with the high filler content is the prerequisite for the extraordinary physical properties of the nano-filled composite.