tablet press

A tablet press is the machine that turns loose powder into finished tablets by squeezing it between two metal rods. Picture a coin stamp: powder fills a hole (the die), an upper and a lower rod (the punches) press in from both sides, the powder is compacted into a solid disc, and the lower punch then lifts the tablet out so the cycle repeats.

Each cycle has the same basic stages: filling the die with a measured volume of powder, compression as the punches squeeze together against set pressure, and ejection of the formed tablet. A simple single-station press has one die and works slowly; a rotary press carries many dies on a spinning turret that passes between compression rollers, producing hundreds of thousands of tablets per hour. The punch shape sets the tablet's size, curve and any imprinted logo or score line.

How well the press performs depends heavily on the powder fed to it: poor flow gives uneven die filling and variable tablet weight, while poor lubrication causes sticking and capping. This is why granulation, glidants and lubricants matter so much — the press only reveals problems already present in the blend.