Granulators high-speed

FIG. 20-84 The Schiigi Flexomix vertical high-shear continuous granulator, Shaft speeds range from 100-.3500 rpm, capacities from 0,1 to 200 megagrams per hour, and power requirements from 1-100 kW Coutiesy of Hosokawa Micron Australia Pty. Lid.)... 

There are a number of mixing and processing techniques which have been used successfully to color granulated or powdered polyolefin with pigments or pigment preparations. Powders, for instance, are processed primarily with high-speed mixers, while granulated types respond better to slower mixers. 

The important concept for scale-up is the principle of similarity (1-6). When scaling up any mixer/granulator (e.g., planetary mixer, high-speed mixer, pelletizing dish, etc.), the following three types of similarity need to be considered geometric, kinematic, and dynamic. Two systems are geometrically similar when the ratio of the linear dimensions of the small-scale and scaled-up system are constant. 

Constant values and reproducibility of the process are important facts of quasi-continuous granulation. The tests also show equal or better quality of granules and tablets, compared to common granulation equipment (Diosna P-600 high-speed granulator). 

Figure 12.13. Pin mixers which operate at high speed for granulation of fine and aerated powders, (a) Pinmixer for the granulation of wetted fine powders, (b) Performance of a pinmixer, dimensions 0.67 m dia by 2.54 m, for pelleting a furnace oil carbon black Capes, 1980).

Lubricant The lubricant needs to be distributed uniformly in the mixture/granulation for the high-speed compression operation. Uneven distribution of the lubricant can result in picking and sticky problems during compression. It can also lead to tablet performance problems (low dissolution due to excessive lubricant in some tablets). 

P. Holm, T. Schaefer, H.G. Kristensen, Granulation in high speed mixers. Part V. Power consumption and temperature changes during granulation, Powder Technol. 43 (1985) 213-223. 

Holm P, Jungersen O, Schaefer T, Kristensen HG. 1983. Granulation in high speed mixers. Part 1 Effects of process variables during kneading. Pharm. Ind. 45 806. 

Schaefer T, Bak HH, Jaegerskou A, Kristensen A, Svensson JR, Holm P, Kristensen HG. 1986. Granulation in different types of high speed mixers. Part 1 effects of process variables and up-scaling. Pharm. Ind. 48 1083. 

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