This is an early-type tablet press with both the upper and lower parts open and with some parts on the upper part painted which was not acceptable any more after the 80s.

Tablets are probably the most common pharmaceutical dosage form, and they may vary in size, shape, colour and coating. They are made by the compression of suitably processed granules and powders by trapping the material into a cavity and then compressing it.

There are four stages in the compression cycle, but they occur so quickly it is not possible for the human eye to pick them up. These are filling, metering, compression and ejection.

Filling: The powder is fed via a hopper which is adjusted upwards or downwards to give the required flow depending on the speed of the machine, and the powder flows onto a rotating turret that contains a number of cavities of specified size (called B, D, BB etc.). A feed-frame prevents the powder from escaping from the rotating turret and keeps it confined to a specific space on the turret. In each cavity a die is inserted which has an inner hole in the shape and size of the tablet. A lower punch (with the upper tip moulded in the shape and size of the tablet) is inserted at specific stations below the turret and enters the die. As the turret rotates, powder is trapped between the lower punch and the die walls.

Metering: The lower punch can be adjusted up or down to decrease or increase the volume between itself and the walls of the die thereby decreasing or increasing the volume of powder that will be trapped and thus adjusting the weight.

Compression: The basic principle in tablet compression is hydraulic pressure. An upper punch (also with its upper tip moulded in the shape and size of the tablet) is pushed downwards and into the die by means a compression roll compressing the powder and forming a tablet.

Ejection: The upper punch then retracts above the turret, and the lower punch is raised to eject the tablet which leaves the machine via a downwards-sloping chute.