Adhesion, frosting, bridging... Common faults and countermeasures of film coating machines

【Technical Articles of Pharmaceutical Network】Film coating machine is an integrated equipment that integrates strong electricity, weak electricity, hydraulic pressure and pneumatic
.

After the film coating is polished, the color is bright, and the complete consolidated coating produced by the crystallization of sugar on the surface can not only prevent the chip from oxidative deterioration, moisture or volatilization, but also cover the unpleasant taste of the chip when taking it
.

In recent years, with the continuous development of China's pharmaceutical industry, the market demand for film coating machines is also considerable
.

From the structural point of view, the film coating machine is mainly composed of the main machine (original sugar coating machine), the controllable normal temperature hot air system, and the spray system for automatic liquid supply and air supply
.

The main motor is variable frequency speed regulation, which can spray coating accessories onto the surface of the tablet with a high atomization spray gun, and at the same time the tablet moves in a continuous and complex trajectory in the coating pot, so that the coating liquid is evenly coated on the core of the tablet.
There is a controllable room temperature hot air in the pot to dry the tablets at the same time, so that the surface of the tablet can quickly form a firm, dense, complete and smooth surface film
.

Today, film coating machines are widely used in the pharmaceutical industry, but under the condition that the quality of the coating powder remains unchanged, many users occasionally encounter some failures in the coating operation, such as sticking tablets, frosting, racking bridges,
etc.

In this regard, some manufacturer's technicians said that these are common problems, as long as you master the corresponding solutions, you can no longer be troubled by them
.

The author lists 8 common faults and countermeasures of film coating machines, which are only for industry reference
.

 　　Sticky sheet Sticky sheet is mainly because the spray volume is too fast, which violates the principle of solvent evaporation balance and makes the sheets stick to each other
.

In this case, the spray amount of the coating liquid should be appropriately reduced, the temperature of the hot air should be increased, and the speed of the pot should be accelerated
.

 　　Frost spraying If there is a "frosting" situation on the surface of the coating film, there is no need to make a big mess.
This phenomenon is caused by the high humidity of the hot air, the long spraying process and the poor atomization effect
.

At this time, it is only necessary to appropriately reduce the temperature, shorten the spray process, and improve the atomization effect
.

 　　The appearance of the logo on the word sheet on the surface of the "bridging" coating film is very important and needs to be clearly visible
.

The appearance of "bridging" means that the marking of the coat film on the lettering sheet is blurred
.

In this case, the coating spray speed should be slowed down, the drying temperature should be lowered, and attention should be paid to controlling the hot air temperature
.

 　　The appearance of "orange peel" film If the drying is not appropriate, the spray pressure of the coating liquid is low and the sprayed droplets are heated and concentrated unevenly, which will cause the coating film to appear ripples
.

In this case, the evaporation rate should be controlled immediately and the spray pressure should be increased
.

 　　Spots appear Spots are caused by uneven mixing or insufficient fineness of solid-like properties when preparing the coating solution
.

This also reminds the user that when preparing the coating liquid, it should be fully stirred evenly
.

 　　There are cracks on the surface of the tablet If the solid content of the coating liquid is not selected properly, the speed of the film coating machine is too fast, and the spray volume is too small, the tablet performance will appear cracks, cracks, peeling or the edge of the tablet is worn
.

In order to avoid this situation, the user should select the appropriate solid content of the coating liquid, and adjust the rotation speed and spray volume appropriately
.

However, if the hardness of the core is too poor, the formula and process of the core should be improved
.

 　　Pinholes on the surface of the coating If you find pinholes on the surface of the coating, this is caused by excessive air entrapment in the preparation of the coating solution
.

Users should avoid getting involved in too much air when dispensing
.

 　　There is a color difference between the tablets The color difference is caused by the uneven fan surface of the spray, or the excessive solid content of the coating liquid and the slow rotation speed of the coating machine
.

At this time, the spraying angle of the spray gun should be adjusted, the solid content of the coating liquid should be reduced, and the rotation speed of the film coating machine should be appropriately increased
.