Compression granulation can be in the form of roll and wheel rolling type.
Dry materials are agglomerated under pressure into dense and hard chunks (cake material), called the extrusion process.
The cake material is then crushed and screened into granular material called the granulation process.
The role of extrusion is to squeeze out the air between the particles, and the other is to make the particle spacing close enough to produce attractive forces such as van der Waals forces, adsorption, crystal bridges and embedded connections.
Extrusion granulation of particles is mainly by the strength of the particles formed by the force between molecules.