Although many applications that require the use of CMC use low percentages (<2%), most medical gels require a loading of CMC that will result in extremely high viscosities (1 million+ cps). Often, CMC loadings of 4% or greater are required to give the final product its desired viscosity.
Conventional agitators (axial / radial flow impellers, sawtooth dispersers) are unable to create the fluid circulation necessary to properly disperse 4%+ powdered CMC dispersions. The consequence of insufficient agitation is the formation of non-dispersed lumps of CMC that may never be dispersed into the viscous bulk.
Once the bulk becomes highly viscous, it becomes extremely difficult to wet additional CMC into the bulk. Powder will tend to remain on the surface and not get drawn down into the bulk.
The Ross VersaMix, a versatile multi-agitator mixing system has the high-shear mixing capability and the flow generating capability to disperse and mix high percentage CMC dispersions.