Pros & Cons

Pros & Cons

Below you can find some Pros & Cons for Freeze Granulation of powders


of Freeze Granulation compared with Spray Drying
The granule density can be controlled (solid content of the slip)
No cavities (voids) in the granules
No migration of small particles and/or binder gives a high degree of granule homogeneity
Nanopowders can be granulated and dried into a powder and then re-dispersed to nanopowders again avoiding agglomeration (aggregates) of nanoparticles, which is not possible with other granulation methods like spray drying
Low temperature granulation and drying of pharmaceuticals, drugs, biomaterials and fine chemicals
A mild drying procedure minimises oxidation of non-oxides and metals
Lower granule density and evenly distributed pressing aids gives softer granules and ensure that all granules are broken during compaction
 Low waste of material (high yield)
 Not only large quantities but also very small experimental batches 50–100 ml slip) can easily be processed
 The equipment is easy to clean (allows the use of latex as binder)
 Possibility of recycling organic solvents


of Freeze Granulation
 Two process steps: spray freezing and freeze drying
 Limitation in the choice of solvent, based on the freezing properties – a freezing point between –20 and +10 °C is recommended (water and cyclohexane)
 Lower tap density of the granules requires a larger fill volume (higher pressing die)
 Large-scale equipment with a capacity beyond 100 kg granules per day needs to be further developed