Application Note

Double Planetary Mixing & Drying Of Granulations For Vitamin & Mineral Supplements

Source: Charles Ross and Son Company

Ross Double Planetary Mixers are well-proven in the manufacture of many vitamin and mineral supplements. These machines blend dry ingredients by rotating two identical blades on their own axes as they orbit on a common axis. The stirrers contact virtually every point of the batch and continuously move new materials from the sidewalls to the center of the vessel. As a result, a completely homogenous mixture of the base carrier, vitamins, minerals, botanical extracts and other nutritional ingredients is achieved in a short period of time. This is followed by spraying an aqueous solution through a multi-nozzle manifold positioned in the hood of the mixer. A metering pump accurately controls the liquid flow rate while the agitated batch transforms into a wet granulated state. One main advantage of the planetary blades is their ability to impart a very thorough mixing action even when the product is dense or not free-flowing.

The final stage of the process is vacuum drying to remove excess moisture from the batch. As heat and vacuum are applied, the stirrers continue to mix the granulation but this time at lower speeds, just enough to ensure uniform temperature while maintaining the size of the granules.

Vitamin manufacturers that have successfully transferred their process from multiple pieces of equipment to a Ross Double Planetary Mixer benefited from significantly shorter cycle times, some by as much as 60%. In addition to simpler handling, cleaning and maintenance, the risks for product contamination and batch-to-batch inconsistencies are also greatly minimized.