The feeding system of the tablet press is generally divided into three types: the shoe feeding system of the single punching machine, the monthly feed system of the ordinary low-speed rotary tablet press, and the forced feeding system of the partial press. High speed and high speed tablet press.

1. The structural characteristics of the shoe repair system of the single punching machine and the comparison of the tableting process

The main structure of the shoe feeding system is shown in Figure 1. The feeder is in the shape of a shoe and is driven by a cam to swing left and right on the plane of the mold to complete the feeding, scraping and pushing operations.

The working process of the shoe feeding system is shown in Figure 2. Lift the upper punch, move the feeder to the top of the die hole, lower the lower punch to a suitable depth (so that the weight of the contained particles is exactly equal to the weight of the tablet), the feeder swings on the die, and then the pellets fill the die Hole; (two) scraping. The feeder is separated from the mold hole so that the particles in the mold hole are flush with the upper edge of the mold hole. (c) Tableting. Lower the upper punch and compress the granules into tablets; (d) Compressing tablets. The upper punch is raised and the lower punch is raised so that it is flush with the edge of the die hole. At this time, the paper feeder moves to the die hole again, pushes the tablets into the receiver, and at the same time the lower punch descends, the die is filled with particles again for the second paper feed, and this operation is repeated.

2. The structural characteristics of the lunar grid feeding system of the ordinary medium and low speed rotary tablet press and the comparison of the tableting process

Figure 3 shows the feeding system of the moon-shaped grid of an ordinary low-speed rotary tablet press. The moon-shaped grid feeder is fixed on the template of the turntable, and the bottom surface of the feeder maintains a certain gap (0.05). ~0.1mm) and the surface of the template. When the rotating mold ring passes under the feeder, the drug particles in the grid will fall into the mold hole, and multiple curved grid plates will cause multiple drug fillings. The last grid of the feeder is equipped with a scraper, which is tightly attached to the working surface of the turntable, which can rotate the turntable and the mold ring, and scrape the excess particles on the surface of the mold ring. , And then punch down again to fall again, so that after the scraper scrapes the material, the powder in the mold hole will be impacted.

The tableting process of the moon-shaped grid feeder.
(1) Filling. When a hole is punched under the hopper, the particles will be filled into the die hole. To
(2) Scratch. When rushing down to the upper plane of the feeding rail, scrape off the excess particles with a scraper;
(3) When the lower punch travels to the upper side of the lower press wheel and the upper punch travels to the lower side of the upper press wheel, the distance between the two punches is the smallest, and the granules are compressed into tablets.
(4) Promote film. After pressing the tablet, the upper and lower punches respectively rise and fall along the guide rail. When the lower punch reaches the upper side of the exit rail, the tablet is pushed out from the die hole and introduced into the container through the scraper, and so on.

3. Comparison of the structural characteristics of the high-speed tablet press and the high-speed tablet system and the comparison of the tableting process

The forced feeding system is a feeding system widely used in sub-high-speed and high-speed rotary tablet presses in recent years (as shown in Figure 5). The forced feeding system is mainly composed of three parts: hopper, feeding motor and forced feeding machine. The hopper is mainly used to store materials, and its lower part is connected to a forced feeder. The feeding motor is the power source of the forced feeder, with frequency conversion and speed regulation; the forced feeder can be divided into a gear box and a feeder. The gear box transmits the power of the feed motor to the two impellers of the feeder. The two impellers rotate in opposite directions to force the material to fill the middle die hole. The tablet pressing process of the forced feeding system is basically the same as that of the crescent grid feeding system, and is divided into four steps: filling→leveling→compacting→pushing.

4. Comparison of tablet weight difference among the three feeding methods of rotary tablet press

The current feeding method is to use the volume of the material to control the weight of the tablet, g = ρv (where g is the weight of the filling material, ρ is the density of the material, and v is the volume material of the filling material). Now the volume of the filling is fixed Of the weight