Dry Granulator Manufacturer

How does a dry granulator achieve the granulation of dry powders without the use of a binder?

A dry granulator achieves the granulation of dry powders without the use of a binder through a mechanical process that involves compaction and size reduction. Here's a step-by-step explanation of how this is typically done:

Feeding: Dry powders are fed into the granulator. The powders can be a variety of materials, such as pharmaceutical excipients, food ingredients, or chemical compounds.
Compaction: The dry granulator uses a roller or a series of rollers to compress the powders. The pressure applied by the roller causes the particles to stick together, forming larger clumps or compacted masses.
Breaking: After compaction, the larger clumps are then broken down into smaller granules. This can be achieved through various methods, such as:
Impact: Using a cutting or crushing mechanism to break the compacted mass into smaller pieces.
Shear: Applying a shearing force to the compacted mass, which can be done by rotating blades or discs that cut through the material.
Screening: The granulated material is then passed through a screen or sieve to separate the desired granule size from oversized particles. The oversized particles can be recycled back into the granulator for further processing.
Classifying: In some cases, a classifier may be used to ensure that the granules are of a uniform size. The classifier can separate the granules based on their size and density, allowing only the desired granule size to pass through.
Drying: If the granulation process introduces moisture or if the powders are hygroscopic, a drying step may be necessary to remove excess moisture and ensure the stability of the granules.
Cooling: If the process generates heat, a cooling mechanism may be used to maintain the optimal temperature for granulation and to prevent degradation of heat-sensitive materials.
Mixing: In some cases, the dry granulator may also have a mixing function to ensure that the powders are evenly distributed before compaction and granulation.
Automation and Control: Modern dry granulators often come with automated controls that allow for precise adjustments to the compaction force, screen size, and other parameters to achieve the desired granule characteristics.

By using mechanical forces to compact and then break down the powders, a dry granulator can effectively granulate dry powders without the need for a binder. This process is particularly useful for materials that are sensitive to moisture or where the addition of a binder would be undesirable.