Tablet Press Tips

Tablet presses are mainly used in the research of tablet technology in the pharmaceutical industry. Tablet presses are automatic continuous production equipment that presses granular materials into round, special-shaped, and tablet-shaped materials with a diameter of no more than 13 mm, and with text, symbols, and graphics. Some pharmaceutical tablet presses produce burrs and dust during tablet pressing. They should be equipped with a tablet screener for dust removal (more than twice) and must meet GMP standards.

Chinese name: tablet press; English name: tablet press machine

Definition:

Tablet press definition: According to the terminology standard, the following definitions are given for tablet presses:

(1) Tablet press, a machine that presses dry granular or powdery materials into tablets through a mold.

(2) Single-punch tablet press, a tablet press with a pair of molds that perform vertical reciprocating motion.

(3) Rotary tablet press, a tablet press with multiple molds evenly distributed on a rotating turntable that perform vertical reciprocating motion along a certain trajectory.

(4) High-speed rotary tablet press, a rotary tablet press in which the axis of the mold rotates with the turntable at a linear speed of not less than 60m/min.

Classification: The machine models can be divided into single-punch tablet press, basket-type tablet press, rotary tablet press, sub-high-speed rotary tablet press, fully automatic high-speed tablet press and rotary core-wrapped tablet press.

Structural composition:

A machine that places granules or powdered materials in the die hole and presses them into tablets with a punch is called a tablet press.

The earliest tablet press consisted of a pair of punches, and the punch moved up and down to press the granular materials into tablets. This machine was called a single-punch tablet press, and later developed into an electric basket-type tablet press. The working principle of these two tablet presses is still one-way tablet pressing based on manual die pressing, that is, the lower punch is fixed during tablet pressing, and only the upper punch moves to apply pressure. This tablet pressing method, due to inconsistent upper and lower forces, causes uneven density inside the tablet, which is prone to problems such as cracking.

In response to this shortcoming of the unidirectional tablet press, a rotary multi-punch bidirectional tablet press began to be born. This tablet press presses the upper and lower punches at the same time and evenly, so that the air in the drug particles has ample time to escape from the die hole, improves the uniformity of tablet density, and reduces the phenomenon of tablet cracking. In addition, the rotary tablet press also has the advantages of low machine vibration, low noise, low energy consumption, high efficiency and accurate tablet weight.

The rotary tablet press is a machine that presses granular materials into tablets by pressing wheels with multiple pairs of punches evenly distributed on the turntable and performing circular lifting and lowering movements according to a certain trajectory. The tablet press with a linear speed of ≥60m/min when the punch rotates with the turntable is called a high-speed rotary tablet press. This high-speed rotary tablet press has a forced feeding mechanism. The machine is controlled by PLC and has the functions of automatically adjusting pressure, controlling tablet weight, removing waste tablets, printing data, and displaying fault shutdown. In addition to controlling the tablet weight difference within a certain range, it can automatically identify and remove quality problems such as missing corners and loose tablets.

The tablets pressed by the tablet press were initially flat and round, and later developed into shallow arcs and deep arcs on the upper and lower surfaces, which was for the needs of coating. With the development of special-shaped tablet presses, tablets such as elliptical, triangular, oblong, square, diamond, and circular shapes have emerged. In addition, with the continuous development of preparations, special tablets such as double-layer, three-layer, and core-coated tablets are made due to the requirements of compound preparations and timed-release preparations, all of which need to be completed on special tablet presses.

With the development of market demand, the scope of application of tablet presses is becoming wider and wider. It is no longer simply limited to pressing Chinese and Western medicine tablets, but can also be widely used to press health foods, veterinary tablets, chemical tablets: such as mothballs, washing blocks, Smurf blocks, art powder, pesticide tablets, etc., food tablets: chicken essence blocks, isatis root blocks, Shenqu tea blocks, compressed biscuits, etc.

Working process of tablet press

The working process of tablet press can be divided into the following steps:

1. The punch part of the lower punch (its working position is upward) extends from the lower end of the middle die hole into the middle die hole to seal the bottom of the middle die hole;

2. Use the feeder to fill the middle die hole with medicine;

3. The punch part of the upper punch (its working position is downward) falls from the upper end of the middle die hole into the middle die hole and moves down a certain distance to press the powder into tablets;

4. The upper punch lifts out of the hole. The lower punch rises to push the tablet out of the middle die hole, completing a tablet pressing process;

5. The lower punch drops to its original position to prepare for the next filling.