Granulation Density

Method Product size (mm) Granule density Scale of operation Additional comments Tyj)ical applications... 

Particle density. The mass of particles divided by the volume as determined by the displacement of mercury (pores greater than 10 /xm). For nonporous solids, similar to true density [62]. Also known as granule density [49]. 

White monoclinic deliquescent crystals or granules density 1.280 g/cm melts at 116°C highly soluble in water (102 g/100 g at 0°C), solubility rapidly increasing with temperature (i.e., 531 g/100 g at 80°C) soluble in liquid ammonia, alcohol and ether. 

Colorless trigonal crystals or fine white crystals or granules density 3.27 g/cm3 at 18°C melts at 350°C decomposes at about 370°C evolving oxygen moderately soluble in water, 13.3 g/lOOmL at 40°C slightly soluble in alcohol insoluble in acetone. 

Colorless rhombohedral crystals or dehquesc granules density 1.91 g/cm melts at 167.5°C decomposes on further heating highly soluble in water, 331 g/lOOmL at 18°C, much greater solubdity in hot water, 657 g/lOOmL at 80°C soluble in alcohol insoluble in ether. 

The dodecahydrate is made up of translucent crystals or granules density 1.524 g/cm3 readily loses five water molecules on exposure to air at ambient temperature melts at 35°C when the salt contains all water of crystallization loses all water at 100°C. 

Monohydrate white orthorhombic crystals or granules density 2.04 g/cm loses its water of crystallization at 100°C very soluble in water, pH of 1% solution 4.5 insoluble in alcohol. 

Colorless cubic crystals or white powder or granules density 2.986 g/cm melts at 570°C very soluble in water, 80 g/100 mL at 18°C very slightly soluble in ethanol. 

Particle Size (pm) Organics (vol%) Granule Size (pm) Granule Density (%) Fill Density (%)... 

Maintain the fluidized bed height constant. Granule density and attrition rate increase with the operating bed height. 

These studies point towards the need to optimize moisture content of the wet mass and extrudate by careful selection of formulation ingredients and type of extruder. A basket or gear/roll extruder is preferred for a very dense and moist wet mass, as it generates little shear and rise in temperature, while an axial or radial screw extruder which increases granule density and hardness is desirable for a wet mass which is less cohesive with poor binding. 

The granule density may be evaluated considering the quantity of dust fraction (granules smaller than 0.18 mm) after the effect of a particular load. 

Granule density and strength, Proper differential pressure drop across the gas distribution plate is needed for good fluidization Fluidization, granule growth when a critical value is exceeded Granule size and its distribution, spray drying... 

Intraagglomerate granule porosity Pg Apparent agglomerate or granule density gm/cm... 

Parrott evaluated compaction of several pharmaceutical powders into compact sheets that were sized by an oscillating granulator into granules. He studied flake thickness, bulk and tap densities, angle of repose, and flow rate after sizing. His work demonstrated that one could improve most granule densities but not necessarily improve granule flow properties. ... 

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