Take a look at the latest video from Silverson Machines to see how to effectively dispersing fumed silica
Fumed Silica is a notoriously difficult powder to disperse due to its extremely low density. As the powder is so fine, it tends to float on top of liquid surfaces and so it can be very difficult to wet out and processing often takes a long time. This also causes issues due to dusting. A degree of shear is also required to complete dispersion and obtain full yield from fumed silica.
When choosing mixing equipment for this application, high shear mixing technology is far superior to conventional mixers and stirrers which simply aren’t up to the task.
The latest ‘How to’ from Silverson Machines demonstrates how the high shear action of a Silverson mixer draws the powder down into the workhead of the mixer so no powder is left to float on the surface. The powder and liquid is then vigorously mixed in the rotor/stator workhead before being expelled back into the mix, resulting in an agglomerate-free, stable viscosity solution in a fraction of the time taken with conventional methods.