The advantages of modular generators for corona and plasma treatment stations

Corona stations are available in all sizes depending on the application- from 10 inch narrow web lines to wide coating machines and BOPP/BOPET lines of up to 10 meters. Usually, the high frequency high voltage that is needed to power the corona process is provided by generators that have to be upsized with increasing performance requirements.

However, their maximum performance is limited due to the maximum available size of the electrical components in the power inverters. With the maximum performance available on the market – 60kW per generator – and therefore per electrode bar, the limits of the technical possibilities are reached. Not only on extremely wide lines but also at high speed applications or for materials with high demands in terms of corona dosage.

Scaling for pretreatment by means of additional electrodes and a single generator quickly becomes expensive due to larger or additional rollers. A further disadvantage of these large single generators is that a technical defect at a critical part of the inverter can bring an entire web to a standstill.

Overcoming limitations

AFS, from Horgau, Germany, now offers a modular generator design as a solid solution to both problems. AFS’ modular generator overcomes the performance limitations of a single generator and, at the same time, minimizes failure rate.

These generators boast several parallel power inverters, which increase the maximum performance of a single generator to 144kW – more than twice as much as conventional products on the market.

Consequently, modular generators are capable of setting new performance records and are perfectly suited for the power needed for processes with controlled gas, such as plasma treatment systems.

If a module fails, the generator will still operate but with a reduction in power until the module is replaced by a new one – simply “plug and play.” Single modules are identical and thus interchangeable. Clearly, modular generators reduce production line downtime and costly trips by onsite service specialists.

During the development of their modular generator technology, the experts at AFS included the most sophisticated components available, such as a larger TFT color touch screens which employ an intuitive user-interface on the generator similar to the graphics and functions of smartphones and tablets. Operational settings can now be adjusted through the proven rotary knob as well as by means of a touch screen. Additionally, system parameters can be easily adjusted through a password protected area for specific applications.