1Stamping die:

1. A die is a tablet press mold used to press tablets. The working end faces of the upper and lower punches form the surface shape of the tablet, and the diameter of the middle die is the diameter of the tablet. The punching die is the main working component of the tablet press, usually consisting of three parts: upper punch, middle punch, and lower punch. The structure of the upper and lower punches is similar, and their punch diameters are also equal. The punch diameters of the upper and lower punches are matched with the die holes of the middle die, and can slide freely up and down in the middle die holes, but there is no gap that can leak the powder. Therefore, the machining accuracy requirements for stamping dies are very high.

2. According to the shape of the punching die structure, it can be divided into circular and irregular shapes (including polygons and curved shapes). The shape of the punch end face includes flat, oblique, shallow concave, deep concave, and composite shapes. Flat and oblique punch heads are used to press flat cylindrical tablets, shallow concave heads are used to press double convex tablets, deep concave heads are mainly used to press the chips of coated tablets, and composite heads are mainly used to press irregular shaped tablets. In order to facilitate the identification and administration of drugs, drug names, dosages, and vertical and horizontal lines can also be engraved on the end face of the die. When compressing tablets of different doses, appropriate sized punching dies should be selected.

2、 The working process of tablet press：

1. The punch part of the downward punch (with its working position facing upwards) extends from the lower end of the middle die hole into the middle die hole, sealing the bottom of the middle die hole;

2. Fill the drug into the middle mold hole using a feeder;

3. The punch part of the upward punch (with its working position facing downwards) falls into the middle mold hole from the upper end and descends a certain stroke, pressing the powder into tablets;

4. Lift the hole upwards. Push the tablet out of the middle mold hole and complete one tablet pressing process;

5. Lower down to the original position and prepare for the next filling.

1. Dose control

Various tablets have different dosage requirements, and large dosage adjustments are achieved by selecting punching dies with different punch diameters. After selecting the die size, the small dose adjustment is achieved by adjusting the depth of the punch into the middle mold hole, thereby changing the actual length of the sealed middle mold hole and adjusting the filling volume of the drug in the mold hole. Therefore, there should be a mechanism on the tablet press to adjust the original position of the punch in the mold hole to meet the requirements of dosage adjustment.

2. Control of tablet thickness and compaction degree

The dosage of medication is determined based on the prescription and pharmacopoeia and cannot be changed. For the requirements of storage, transportation, preservation, and disintegration time limits, there are also requirements for a certain dosage of pressure during tablet pressing, which will also affect the actual thickness and appearance of the tablets. The pressure adjustment during compression is *. This is achieved by adjusting the downward displacement of the punch in the mold hole. Some tablet presses not only have upward and downward movements during the tablet pressing process, but also downward upward movements, which are completed by the relative motion of upward and downward movements. But pressure regulation is mostly achieved through mechanisms that adjust the amount of upward and downward movement to achieve pressure regulation and control.

1. The single punch press uses a cam (or eccentric wheel) linkage mechanism (similar to the working principle of a punch press) to produce relative motion between the upper and lower punches and press the tablets. Single punch type does not necessarily have only one pair of stamping dies working, it can also have two or more pairs, but multiple pairs of stamping dies stamping at the same time, which results in strict requirements for the stability and reliability of the mechanism, complex structure, and is not commonly used. The single stamping machine is an intermittent production method with intermittent feeding and discharging, resulting in low production efficiency. It is suitable for laboratory testing and large-scale tablet production.

2. The multi punch rotary tablet press is a device that arranges multiple sets of punching dies in a circular shape on a working turntable, and the tail of each upper and lower punch is controlled by a fixed lifting guide rail. When the upper and lower strokes rotate synchronously with the working turntable, they are controlled by the guide rail to perform axial lifting and lowering movements, thus completing the pressing process. At this point, the process of the tablet press is continuous, with continuous feeding and continuous dispensing of tablets. From the perspective of the whole machine, the force is relatively uniform and stable, and it is widely used in formal production. The multi punch rotary tablet press is often classified according to the punching modulus, such as commonly known as 19 punch, 33 punch press, etc.