The rotary press machine, also called the high speed pill press is a machine used in the production of tablets usually in the pharmaceutical industry. The equipment is designed for continuous production of tablet shaped medications.
Operating Principle
The operation of the tablet press machine is handled in various stages as summarized below;
Powder Filling Stage
This is the preliminary stage where the powder formulation is fed into the equipment. It is fed into a hopper system where it gradually flows into the tooling system for compression to be done.
Powder Metering Stage
The tablet machine must ensure that there is never an excess of any powder as this will cause inconsistencies in the final product. To achieve this, the metering process is subdivided into four stages which are the die filling stage, tablet compression stage, tablet ejection stage, and tablet detachment stage. In this process there is provision for adjustment in the volume of the fill to ensure only a constant volume is packed.
The rotary tablet press derives its name from the presence of a rotating turret that holds the tablet tooling system. The production capacity of the machine is dependent on the size of the turret. This section has four main parts which are;
- Upper turret; the area that holds the upper punches
- Lower turret; houses the lower punches
- Die table; the area that positions the dies.
When the right depth and volume of the powder is achieved, the upper and lower punches compress the powder in a series of pre-compression and compression stages to achieve the right thickness and hardness.
Double rotary tablet press
In all the tablet machine design the compression process remains the same. However the double rotary tablet press machine is designed for greater production output as it has a higher number of punch dies and more automation for the greater production capacity.
R&D tablet press machine
This tablet compression is mainly used in research and development mostly in conducting of clinical trials. It has all the features of the other tablet compression machines and is mostly used in research laboratories.
The mini tablet press machine and the single rotary tablet press machines are also relatively small scale tablet manufacturing equipments.
Bi layer tablet press Machine
This is a special purpose tablet press machine used in making of bi layer tablets. The Double Sided Rotary Press Machine is used in the manufacturing of quality bi layer tablets. The equipment has been modified such that there is lower compression in the first layer and greater compression in the second layer to prevent separation of the layers.
Design Features of Rotary Tablet Machines
Some of the main features of the tablet machines include;
- Sturdy machine frame and stainless steel housing that ensures stability during the compression processes.
- The lower guards and made using steel parts while the upper guards and made of clear acrylic material to allow for viewing of the compression process.
- They are fitted with electronic counter system.
- AC variable drive system for efficient performance
In conclusion, the rotary tablet press machine is one of the most important and widely used machines in pharmaceutical manufacturing and there have been continued innovations in design to enhance efficiency.