granulating

Granulating, or granulation, is a process in which fine powders or small particles are bound together to form larger, multi-particle units called granules. Granules typically have improved flowability, compressibility, and handling properties compared to the constituent powders, and they can exhibit more uniform composition and release characteristics in final products.

There are several approaches to granulation. Wet granulation uses a liquid binder or solvent to promote particle cohesion; dry granulation compacts powders under pressure without liquids, followed by milling to break the compacted mass into granules; and advanced techniques such as spray granulation, extrusion-spheronization, and fluid-bed granulation combine binding and shaping in different ways.

Typical steps include sizing of raw materials, wetting or binding, agglomeration, drying, and screening to obtain the desired granule size distribution. Process parameters such as moisture content, binder type, mixing time, temperature, and drying conditions strongly influence granule quality.

Applications span pharmaceuticals (solid oral dosage forms), fertilizers, agrochemicals, food ingredients, and ceramics; in each sector granulation aims to improve flow, reduce dust, enable uniform dosing, and control release or dissolution profiles.

Considerations include material sensitivity to moisture, potential binder residues, scale-up challenges, equipment selection (high-shear mixers, globe mills, fluid-bed or twin-screw granulators), and quality control using sieve analysis, angle of repose, bulk density, and moisture content. Granulation thus serves to convert powders into more manageable, consistent, and functional granules across multiple industries.