Common problem handling and maintenance of rotary tablet press
The film weight is over the difference (the difference in finger weight exceeds the limit prescribed by the Pharmacopoeia)
1 The particle size distribution is uneven, and the particle flow rate is different when the tablet is pressed, resulting in uneven grain thickness in the pores of the middle mold. For example, if the amount of coarse particles is large, the sheet is light, and if the fine particles are large, the sheet weight is heavy. Solution: Mix the granules or sieve out too much fine powder.
2 If the fine powder adheres to the punch and causes the slamming, the difference in the weight of the sheet can be made larger. At this time, the undershooting rotation is not flexible, and it should be checked in time, the die is removed, and the undercut and the middle die hole are cleaned.
3 The flowability of the particles is not good, and the amount of particles flowing into the middle die hole is often small, causing the difference in the weight of the film to be too large and exceeding the limit. Solution: Re-granulation or adding a suitable glidant such as micro-silica gel to improve particle flow.
4 particle layering. Solve particle stratification and reduce the difference in particle size.
5 smaller tablets use larger granules. Solution: Select the appropriate size of the particles.
6 The hopper is blocked, and this phenomenon often occurs in drugs with strong viscosity or moisture permeability. The hopper should be dredged, the tableting environment should be kept dry, and the glidant should be added as appropriate.
7 The material storage amount in the material is large, and the control is within 50%.
8 The feeder is unbalanced or not installed in place, resulting in uneven packing.
9 The scraping board is not flat or poorly installed. Solution: Leveling.
10 with forced feeder, forced feeder dial speed does not match the turntable speed. Solution: Adjust the consistency.
11 The punch has poor fit with the hole in the middle die. For example, more powder is leaked between the outer periphery of the undershoot and the wall of the die hole, causing the phenomenon of "burdening" under the undershoot, resulting in insufficient material filling. The punch should be replaced. Medium mode.
12 under the length of the rush, the difference is poor, resulting in uneven filling. Solution: Correction, within ±5μm.
13 undershoot with damping, the damping force of the damping screw adjustment is not good. readjust.
14 filling rail wear or instability of the filling mechanism. Solution: Replace or stabilize.
15 pursuit of production, the rotation speed of the turntable is too fast, the filling amount is insufficient. In particular, when pressing large pieces, it is necessary to appropriately reduce the rotation speed to ensure that the filling is sufficient.
16 The tablet press is too large, the structure is loose, the assembly is unreasonable or reassembled; the pressure setting of the tablet press is too large to reduce the pressure.