WET GRANUALATION MECHANISM:

Particle size enlargement methods:Granulation,(agglomeration by agitation)Compaction (e.g. tabletting),Extrusion,sintering,spray drying andprilling.

Granulation is the process of collecting particles together by creating bonds between them. Bonds are formed by compression or by using a binding agent.

Why enlarge particle size: To prevent segregation of the constituents of the powder mix. To improve the compaction characteristics of the Mix. To produce uniform mixtures. To eliminate poor content uniformity. To produce dust free formulation. To capture and fuse small quantities of active material. To control density.

Roller compaction

WET GRANUALATIONImportant steps involved in the wet granulationi) Mixing of the powder and excipientsii) Preparation of binder solutioniii) Mixing of binder solution with powder mixture to form wet mass.iv) Coarse screening of wet mass using a suitable sieve (6-12 # screens).v) Drying of moist granules.vi) Screening of dry granules through a suitable sieve (14-20 # screen).

TUMBLING GRANUALATOR (1-20mm granules)1. DISC GRANUALATOR2. DRUM GRANUALATOR Granule density generally falls between that of fluidized-bed and mixer granulators and it is difficult to produce highly porous agglomerates in tumbling granulators. Tumbling equipment is also suitable for coating large particles, but it is difficult to coat small particles, as growth by coalescence of the seed particles is hard to control. Drum and disc granulators generally operate in continuous feed mode. A key advantage to these systems is the ability to run at large scale. Drums with diameters up to four meters and throughputs up to 100 ton/hr are widely used in the mineral industry.

MIXER GRANUALATOR (