Freeze Granulation offers the possibility to produce very soft, spherical granules which show an excellent flowability. The granules can be compressed to compacts of high homogeneity and they are completely redispersable. Freeze Granulation is a granulation technique which combines the advantages of spray drying and freeze drying. Hard granules are prevented by this technique excluding capillary forces during drying.
Freeze granulation, as opposed to spray drying, has been shown to produce protein particles with light and porous characteristics, which offered powders with superior aerosol performance due to favorable aerodynamic properties, suitable granulation technology for protein inhalation powders.
Migration and segregation of the constituents that is common in other granulating processes such as spray drying is avoided in Freeze Granulation. By instant freezing of small droplets critical ice crystal growth is avoided. The freeze drying where the liquid medium is sublimated ensures homogeneity preservation, limited oxidation and soft bonds within the granules. This provides the best possible condition for any subsequent processing such as easy pressing to homogenous compacts, easy re-dispersing in a liquid, sintering of catalytic particles, dosage processes etc.
What is the difference between spray drying and Freeze Granulation? For more info, please go to our Pros & Cons.
The best way to find out if Freeze Granulation is suitable for your material is to let us do a test granulation. Freeze Granulation will be more expensive than spray drying as it is a two-step process. The relative difference depends on the scale and Freeze Granulation is more suitable for small or medium size batches where the demands on granule quality is high whereas spray drying is most suitable for large scale processing.