Analysis and elimination of the common faults of the rotary tablet press machine

Analysis and elimination of the common faults of the rotary tablet press machine

No matter high-speed tablet press or ordinary tablet press, but the basic working principle of tablet press is basically the same. Combined with the working principle of tablet press and the common faults of tablet press in the actual use process and how to deal with them are analyzed:

1. The working principle of rotary tablet press includes filling, quantitative, pre pressing, main press forming, tablet output and other processes. The upper and lower punch dies are driven by the punch plate and move from left to right along the upper and lower guide rails respectively. When the punch moves to the filling section, the upper punch moves upward to bypass the forced feeder. At the same time, the lower punch moves downward under the action of the pull-down cam. At this time, the upper surface of the lower punch and the die hole form a cavity. The powder particles are stirred by the forced feeder impeller and filled into the cavity of the middle die hole. The lower punch passes through the Overfilling occurs when the lowest point of the pull-down cam is crossed. The punch of tablet press continues to move with the punch plate, and the lower punch gradually moves upward when it passes through the filling cam, and pushes the redundant powder particles in the cavity out of the middle die hole and enters the quantitative section. In the quantitative section, the upper surface of the filling cam is horizontal, and the lower punch keeps horizontal motion. The quantitative scraper scrapes out the redundant powder particles on the upper surface of the middle die, ensuring the same filling amount of powder particles in each middle die hole. The down punch protection cam pulls down the down punch, and the up punch moves downward under the action of the down punch cam. When the middle die hole moves out of the cover plate, the up punch enters the middle die hole. When the punch passes through the preloading wheel, it completes the preloading action and then continues to pass through the main pressure wheel. The compaction action is completed by the extrusion of the main pressure wheel. Finally, through the cam of the tablet, it moves up and down, pushes up and down, and pushes the pressed tablet out of the middle mold hole. The tablet enters the tablet outlet device to complete the whole tablet pressing process.

2. Analysis of common faults of powder tablet press

The common faults of the mechanical part of the tablet press are easy to occur in the following parts: guide rail, pressing wheel, overload protection, reducer and; the stamping die of the tablet press and so on; the common problems in the production process are abnormal sound, difference in tablet weight and so on, involving many factors, including both the use factors and improper adjustment factors. During the use of the tablet press, it is necessary to clean the tablet press room regularly, and regularly check and maintain the working parts that are easy to wear. According to the experience accumulated in practical use, this paper introduces how to solve some common faults and maintenance methods.

2.1 abrasion of guide rail on pharmaceutical tablet press:

1) it may be oil cut-off and improper oil filling in the upper flushing, resulting in the phenomenon of lifting and flushing in the upper flushing, resulting in the wear of the upper guide rail. The 35 degree inclined plane shall be repaired in time, and it shall be replaced if the damage is serious. Pay attention to the oiling method during operation, first wipe the remaining oil on the upper punching surface with a clean rag, and then apply a little oil on the small brush, evenly on the upper punching hat head and upper punching rod, so that the upper punching can rotate flexibly. However, the amount of oil should not be too much to prevent oil from penetrating into the powder and causing oil slick. No less than two refuels per shift.

2) the oil quality is not good. Only oil can be selected for lubrication between guide rail and punch rod. 30 gear oil or air compressor oil can be selected

3) the pressing material is too fine and there is a lot of dust, so it must be added lightly when feeding to avoid dust flying, which will make the upper punching, lifting and even wearing the upper guide rail.

4) the pressing material is too wet, and the upper guide rail is worn due to the phenomenon of product hanging or sticking. The material is re baked, and the lubricant is added for rework. In addition, the process formula should be improved to control the particle size distribution, fluidity and compressibility of the material.

5) if the upper punching is not clean, the upper punching, hanging punching, sticking punching and upper guide rail will be worn. The upper punching shall be cleaned and slide freely to the upper punching.

2.2 wear of lower guide rail: wear of lower guide rail bridge plate, repair with oilstone if it is light, and replace if it is seriously worn.

1) if the pressing material is too thin or too damp to make the lower punching hole or the lower punch skinned, resulting in the lower punching hanging punch, sticking punch and the wear of the lower guide rail, the lower punching hole shall be cleaned and the lower punching shall be turned to be flexible. Whether there is any abnormal sound during the operation of the operator during tablet pressing. Shut down the machine in time when hearing the abnormal sound, wipe off the crusting or tablet pressing materials on the punch and punch for rework. In order to avoid the damage of the lower guide rail due to the serious down impact and lifting impact.

2) the down punching is not clean, resulting in the phenomenon of down punching and hanging punching. Brush the lower punching hole. If the punching hole is skinned, the skinning must be cleaned with a scraper. For products with high viscosity, the punch must be cleaned with alcohol to ensure that the punch can rotate flexibly.

2.3 pressure wheel

The pressing wheel is a device to adjust the pressure of the tablet and increase the protection. Its common faults include the wearing of the pressing wheel, the lack of oil or the damage of the bearing of the pressing axle. If the outer circle of the press wheel is seriously worn, resulting in great resistance at the end of the punch rod, the press wheel shall be replaced; if the inner hole of the press wheel and the press axle are seriously worn, the press wheel or the press axle shall also be replaced: sometimes the press axle is broken due to the excessive bearing pressure, most of which is due to the improper adjustment operation due to the difficulty of material pressure, at this time, the press axle shall be replaced, the material shall be adjusted, and the pressure shall be readjusted. In addition, regularly lubricate and maintain the bearing of the compressor shaft, and replace it in time in case of damage.

2.4 overload protection system

The common fault of overload protection system is frequent alarm. The main reason is that the pressure of the tablet is overloaded or the set pressure of the overload protection spring is too small. The solution is to adjust the pressure hand wheel, reduce the pressure or increase the set pressure of the overload protection spring.

2.5 reduction gearbox

The gearbox is composed of worm, worm and box. Its common fault is oil leakage. It is mainly caused by loosening of flange screws or aging of oil seal. The solution is to tighten flange screws or replace oil seal and apply sealant.

2.6 fully automatic rotary tablet press die

Die is an important part of tablet press. The common faults in use are: rod wear, rod wear