Common Problems for film Coating Machine
Writer： admin Time：2022-02-15 16:32 Browse：℃
Coating machines are now widely used in pharmaceutical industry, food industry, biographical industry and so on. It can coat tablets, pills and sugars with organic film, water-soluble film or sugar coat, which can fulfill controlled or sustained release of drugs.
The working principle of coating machines can be explained in detail as follows: uncoated tablets are firstly fed into the rotary drum of the coating machine. And then feed syrup into the drum in several times. As the drum rotates clockwise, tablets roll and rub over and over so that they can be coated by the syrup uniformly. Meanwhile, hot air flowing into the drum can remove water on the surface of syrup coating film. As a result, uniformly coated and smooth tablets can be produced.
It can be seen that a lot of variables should be controlled during production, such as air inlet volume, drum rotating speed, and inlet air temperature, etc.. However, most of coating machines have shortcomings since their control systems adopt relay for logic control. The result is that lots of buttons are used and the control cabinets thus occupy a rather large space. Besides, flying dust will deposit on or around the buttons. Therefore, dead corners are formed, influencing not only regular cleaning but also drugs quality and hygiene. Even some equipment faults might occur due to dust deposit.
In this case, some coating machine manufacturers reform their machines from the perspective of convenience, time saving and stability. They replace relay with PLC for system control, adopt touch screen as HMI instead of buttons for easy operation, add an analog quantity input module and an analog quantity output module, and use frequency converter to regulate rotating speed of the rotary drum. On the reformed machines, users can control start and stop of all action components by controlling on the touch screen and through PLC and relative modules. For example, the temperature can be detected and controlled by FX2N-4AD-PT module and operating frequency of the frequency converter be modified by RS-485 bus. For another thing, frequency converter is the device which can convert the frequency of industrial frequency power supply on the basis of on-off action of power semiconductor device. It can realize functions of soft start of asynchronous AC motor, frequency control of speed, operation accuracy improvement, power factor change, over-current, over-voltage and over-load protection and so on.
Even so, there are also many problems emerging after long-term use, such as mechanical wear and tear of supporting wheel. The supporting wheel is a load bearing part and is also a wearing part. Most problems of them are screw loosening, jam caused by bearing damage, and roller beating caused by nylon wear and tear. Spraying gun is also problematic since some of them, even the imported, will clog finally.
The above problems are common on coating machines. Some have been solved while some are still pending. For higher-efficiency production, customers can select coating machines with high-end configurations. And during practical production, operators can keep regular check and maintenance to the machine. For any problems that users are not able to solve, contact the suppliers immediately, instead of maintaining the machine blindly. Casual maintenance to the equipment might cause secondary damage.
