The solution to the phenomenon of sticking and punching in the process of tablet pressing

The solution to the phenomenon of sticking and punching in the process of tablet pressing

Tablet pressing is a common process in pharmaceutical production. However, in the process of pressing, many users will find the problem of sticking and punching, that is, powder particles adhere to the surface of the punch, can not form a smooth sheet surface, making the pressing products unqualified. So, for this kind of phenomenon, how should solve?

The adhesive punch may appear at any stage of the tablet pressing process, but the adhesive punch is predictable, and the determination of moisture and other properties of particles can help users predict whether the product is adhesive punch or not. The cause of sticking may be related to products, equipment, upstream process or tablet press operation, or may be a combination of several factors.

First, product issues. When the product is pressed, the operator needs to adjust the weight of the tablet first, and then adjust the thickness of the tablet. The hardness was determined by weight, thickness, pressing speed and holding time.

For some pressure-sensitive particles, if there is a problem of sticking and punching, you can quickly press a few rounds of very hard pieces, using pressure to make particles bonded into a piece, and the powder stuck on the washing away. But need to pay attention to the size of the pressure, if more than the load of the die may lead to damage or even fracture of the die.

In addition, experienced operators can also judge whether or not the sound of the tablet press. If there is a phenomenon of sticking and punching, the pressure setting can be changed, such as increasing the pressure, reducing the thickness of the sheet, reducing the preloading thickness, or reducing the speed of the sheet.

Second, equipment. The user needs to choose the regular stamping equipment manufacturer, because the manufacturer will generally do some work to avoid the adhesion, the problem of adhesion. Conditional users can also customize with adhesive characteristics of the die, but also change the height and Angle size, reduce the risk of adhesive.

In addition, the brightness of the steel surface may also occur. For example, the D2 and 440C steels contain more chromium than other types of steel, reducing the impact of adhesion. At the same time can also use special chrome coating, forming a high hardness, wear - resistant punch.

Third, air interception. It is understood that during the process of pressing the sheet, air may be sucked into the concave surface of the punch, so that the air forms a soft area on the surface of the sheet, causing the situation of sticking and punching. In addition, this also happens when the tablet is soft.

In such cases, the solution is to ensure the right holding time, to drain the trapped air, or to increase the main pressure discharge as much as possible. If the above adjustment is not possible, consider using a tapered die to help the air discharge.

Fourth, not properly lubricated. The function of lubricants is to prevent the powder from sticking to the dies, dies and other metal substances during the pressing process, and also to promote the lining. However, users also need to pay attention to the correct use of lubricants, otherwise they can not play a proper role. Generally speaking, the need for pre-treatment to eliminate clumps or larger particles, at the same time the need to let the lubricant mix evenly, and do not over lubrication, otherwise it will also occur.

Fifth, the upstream process. For example, the use of adhesive is not suitable, product drying is not complete, and so on, will also occur. Therefore, different problems should be solved accordingly.

To sum up, the occurrence of adhesive scour during tablet pressing may be related to one or more factors. Users need to make sure that the equipment is not in trouble, starting from the upstream to identify the cause, and make timely solutions.