How to deal with occasional cracks in cooling belt

Cooling belts are important equipment for the production of tablets, but the problem of occasional cracks may occur during use. This situation not only affects the quality of the product, but can also lead to decreased productivity and increased costs. The appearance of cracks is usually related to factors such as the nature of raw materials, formula ratio, equipment adjustment and operating environment. To address these potential causes, the following processing measures can be taken to gradually troubleshoot and solve the problem.  

1. Check raw material properties and granule quality

Lobbing is often related to the nature of the raw material particles in the tablet. If the raw material particles are too coarse, inhomogeneous or have poor flowability, this can lead to uneven shaping during tablet compression, and consequently, to lobbing. It is advisable to first check the size, distribution and flowability of the raw material particles to ensure that they meet the requirements for tabletting. For raw materials with poor flowability, they can be improved by a granulation process, such as wet granulation or dry granulation. In addition, increasing the proportion of lubricants or using excipients with better flowability can also effectively reduce the probability of lobe occurrence.  

2. Optimisation of formulation ratios

Inadequate ratio of components in a formulation is one of the major causative factors for cracking. For example, insufficient binder will reduce the mechanical strength of tablets and lead to cracking; too much disintegrant may cause tablets to expand prematurely and crack during the pressing process. To address this problem, the dosage of excipients such as binders, disintegrants and lubricants should be appropriately adjusted according to the actual production situation to ensure that the formulation can provide sufficient binding force and appropriate disintegration time. In addition, for active ingredients that are difficult to be pressed into tablets, try using excipients that improve tabletability or direct compression techniques.  

3. Check cooling belt moulds and pressure settings

Wear and tear or improper installation of tablet press moulds may result in uneven force and lobing of tablets during forming. Therefore, regularly check the condition of the upper and lower punches and dies to ensure that they are smooth and undamaged. In addition, the pressure setting when pressing tablets needs to be carefully adjusted. If the pressure is too high, the internal stress of the tablet may be too high, leading to cracking; conversely, too little pressure will result in insufficient tablet binding. Therefore, the pressure setting should be optimised according to the requirements of tablet hardness and thickness to ensure moderate strength and complete tablet formation.  

4. Control of operating environment and pressing speed

The operating environment and the running speed of the cooling belt also have an impact on the lobing problem. In a low humidity environment, tablets may be delaminated or lobed due to static electricity, while high humidity may cause moisture absorption problems. Therefore, it is recommended to keep the temperature and humidity of the operating environment moderate, usually at a temperature of 20°C-25°C and a humidity of 40%-60%. On the other hand, too fast pressing speed will lead to insufficient filling time of the punch or uneven material distribution, which will trigger the lobe. Therefore, the tablet pressing speed should be adjusted according to the actual demand during the production process to ensure the stable quality of each tablet.  

5. Enhance production process monitoring and quality inspection

In order to avoid the recurrence of the lobe problem, the monitoring and quality inspection of the production process should be strengthened. During the production of each batch of tablets, the appearance, hardness, thickness and other indicators of the tablets are checked in real time to ensure that problems are detected and production parameters are adjusted in a timely manner. At the same time, online testing equipment, such as tablet hardness tester and thickness measuring instrument, can be equipped to further improve the accuracy of monitoring. In addition, the residual material in the tablet press should be cleaned regularly to avoid affecting the tablet quality due to material mixing or foreign objects.  

6. Summary and Preventive Measures 

The emergence of a tablet problem is usually the result of the superposition of several factors. Therefore, when solving specific problems, it is necessary to comprehensively consider the effects of raw materials, formulations, equipment and environment, and take targeted measures. In daily production, strengthening the maintenance of tablet presses and optimising the adjustment of process parameters can effectively reduce the probability of lobe occurrence. At the same time, the establishment of a standardised production management and quality control system can also fundamentally improve the stability and quality of tablet production.  

Through scientific analysis and treatment, the lobe problem can be effectively controlled, thus ensuring the efficiency and quality of tablet production.