In the production of two-color tablets in the pharmaceutical, food, and health product industries, the Coant (Shandong) two-color tablet high-speed tablet press is the core equipment to ensure efficiency and quality. However, in long-term operation, the equipment is prone to various malfunctions, which can affect production progress. This article focuses on high-frequency equipment issues, identifies the causes and practical solutions to help quickly troubleshoot problems.
1、 Exceeding the weight difference of tablets: precise investigation from materials to components
Problem manifestation
The weight fluctuation of a single two-color tablet produced exceeds the industry or enterprise standard (usually with an allowable error of ± 5%), and some tablets have missing or excess materials.
Common reasons
1. Poor material fluidity: uneven particle size and excessive humidity of dual color materials result in unstable filling amount during feeding;
2. Speed mismatch: The feeder speed is not coordinated with the main spindle speed of the tablet press, and the feeding speed is too fast or too slow;
3. Die wear: After long-term use, the wear on the inner hole of the die increases, and the material filling space becomes abnormal.
Processing Steps
1. Optimize material condition: detect material humidity (recommended to be controlled at 3% -5%), add flow aids such as magnesium stearate (dosage 0.5% -1%), and improve flowability;
2. Adjust the speed parameters: gradually adjust the feeder speed, and after each adjustment, sample and test the weight of 10-20 pieces until the weight fluctuation stabilizes within the error range;
3. Replace stamping die components: Disassemble the stamping die, check the wear of the inner hole, replace it with a new stamping die that meets the equipment specifications, and test produce 50-100 pieces after replacement to verify the effect.
2、 Dual color film layering/loose bonding: focusing on synergistic optimization of materials and pressure
Problem manifestation
There are obvious separation gaps between the two layers of materials in the two-color tablet, or they peel off after being compressed, which affects the appearance and safety of the tablet.
Common reasons
1There is a large difference in material hardness: the particle hardness of the two materials differs by more than 2kg (detected by a hardness tester), and uneven force during compression leads to delamination;
2Improper pressure parameters: The main or pre pressure is set too low, and the two layers of material are not fully compacted and combined;
3Unreasonable feeding process: The feeding sequence is disorderly, or the filling speed is too fast, and the two layers of materials are not evenly adhered.
Processing Steps
1Unified material hardness: By adjusting the amount of adhesive added during granulation (such as hydroxypropyl methylcellulose), the hardness of both materials is controlled at 3-5kg;
2Gradually increase the pressure: Increase the main pressure by 0.5-1MPa each time (to avoid cracking the tablet due to excessive single pressure increase), and observe the bonding effect after pressure testing;
3Standardize the feeding process: fix the order of "adding lower layer material first, filling flat, and then adding upper layer material", reduce the filling speed to 80% of the original speed, and ensure that the two layers are fully in contact.
3、 Abnormal noise during equipment operation: comprehensive inspection from lubrication to installation
Problem manifestation
The noise suddenly increases during equipment operation (exceeding 75 decibels, while the normal operating noise is about 60-65 decibels), accompanied by metal friction sound or vibration sensation.
Common reasons
1Lack of oil in transmission components: Insufficient lubrication in transmission parts such as gears and bearings, resulting in increased friction and noise;
2. Installation deviation of stamping die: The stamping die is not aligned with the center position, or the fixing screws are loose, causing collision with the inner wall of the equipment during operation;
3. Internal component wear: The clearance between vulnerable parts such as cam and guide rail exceeds 0.2mm, resulting in loosening and collision during operation.
Processing Steps
1. Add suitable lubricating oil: After stopping the machine, disassemble the transmission parts and add No. 32 or No. 46 industrial gear oil (as required by the equipment manual) to ensure that the lubrication covers all friction points;
2. Recalibrate the punching die: Loosen the fixing screw of the punching die, align it with the center position with a calibrator, tighten the screw and manually rotate the spindle to check for any jamming or collision;
3. Replace worn parts: Check the clearance between the cam and guide rail, replace parts with excessive clearance, run empty for 5-10 minutes after replacement, and confirm that the noise has decreased to the normal range.