In an OSD manufacturing environment, when the powders and their formulations flow well and consistently through the process, production typically goes smoothly. But what if the flow characteristics of the powder formulation causes issues and is difficult to progress through the process.
Quite often challenges arise due to a very fine material in the formulation. Granulating powder mixture into granules of a larger size should allow for improved flow. This can be done either wet or dry. Wet granulation is dominated by spray granulation where a powder product (or products) is mixed while spraying a binder solution. This solution, combined with the mixing motion, causes the powder particles to adhere to each other forming larger particles called granules. This can be done on a high sheer granulator or a fluid bed setup. While not only being expensive and time consuming, wet granulation is not suitable for heat sensitive materials that could be affected by the binder or the drying step in the process.
The alternative is Dry Granulation where no binder is used and thus a heated drying step is not required. The dry granulation technique used in the PMTC is Roller Compaction.
Dry Granulation Quadro Co-Mill 193.
Granulation within the PMTC is achieved using a conical milling equipment. The ribbon is broken up and added to the mill which consists of a conical screen and a rotating blade very close to the screen, the blade further breaks up the ribbon and forces it through the screen producing granules. The speed of the blade is variable and screens of different sizes are available to achieve the desired granule size distribution.
Eyecon Particle Analyser
To monitor the granule size being produced by the roller compactor and granulator the Eyecon is used. This is an analytical instrument to measure and monitor particles produced via dry granulation processes based on imaging techniques.