Pharmaceutical Manufacturing Handbook: Production and

1062 TABLET PRODUCTION SYSTEMS
FIGURE 5 Example rotary tableting machine: left, machine view; right, detail view into
compression chamber. (Courtesy of Kilian Synthesis 500.)
of the die table determine tablet production. Fast rotary machines have up to
120 rpm of the die table [32] . However, the number of tablets produced per hour
not only is determined by the number of punches and the rotation speed but also
is limited by the deformation properties of the tableted material. Materials need
some time for deformation, and if the time during one compaction cycle is not suffi
cient for compression and compaction of the material, no tablets result from the
process.
In order to increase the production rate of rotary tableting machines, double -
sided rotary machines were build which possess two pairs of compression wheels
and two fi lling shoes. Thus during one rotation double the number of tablets are
produced compared with a one - sided rotary machine. If these machines are equipped
with precompression wheels one machine contains four pairs of wheels.
Special Rotary Machines As already mentioned one special rotary machine works
slightly different — called IMA Comprima (Figure 6 ) [34] . In this machine the material
is fi lled by centrifugal force from the side directly into the die. The upper punch
closes the die at the top and the lower punch closes the die at the bottom. However,
when the given volume in the die is fi lled by the powder, both punches move downward
until the die is completely closed. Then the compression process starts and the
dies pass the compression wheels. After compression the tablet is ejected by the
upper punch at the bottom of the die, contrary to all other rotary tableting machines
which eject the tablet at the top of the die.
High-Speed Rotary Tableting Machines High - speed rotary machines work with
the same principles as all other rotary machines. They possess a huge number of
punch and die sets and often two fi lling stations. Another possibility is to use punch
and die sets which are able to produce several tablets simultaneously. Special tooling
can be used for this purpose; however this is not the subject of this chapter. As