In the automotive and e-mobility sectors, ensuring the cleanliness of bipolar plates during the manufacturing of fuel cells is critical.

These plates play a vital role in transforming hydrogen into electrical energy, and any contamination—such as microparticles, dust, or laser-cutting residues—can compromise the efficiency of the fuel cell. This makes thorough cleaning, particularly steam cleaning, an indispensable step in their production.

Rea Steam Cleaning, thanks to its experience and internal know-how, has patented an in-line washing system specific for bipolar plates.

Patent of our system for cleaning bipolar plates (PDF)...

Benefits of steam cleaning for bipolar plates

Steam cleaning offers an advanced, non-abrasive solution for removing contamination from bipolar plates. By utilizing high-temperature, high-pressure steam, this method effectively cleans the intricate flow field designs of the plates, ensuring that they are completely free from debris.

Here are the main benefits of steam cleaning for bipolar plates:

  • Compact installation: Steam cleaning systems, such as those integrated in tunnel washers, take up minimal space (up to 300 cm in length) and can be easily added to existing production lines.
  • Fast processing time: The cleaning process is swift, with each plate processed in just a few seconds (from 3 to 6 seconds per plate), allowing high throughput on production lines.
  • Sustainability and optimization: All washing cycle operations are performed sequentially. The consumption of water is low, resulting in less polluted water to treat.
  • Low maintenance: The system requires minimal maintenance, with no filters to replace or bath quality to monitor, making it a reliable solution for industrial-scale production.
  • Consistent Results: Because steam is always clean, the process is stable and ensures uniform cleaning across all plates.

Why bipolar plate cleanliness is crucial

Bipolar plates, typically made from graphite composites or metallic materials, are responsible for distributing gases (hydrogen and oxygen), managing water removal, and dissipating heat in fuel cells. Any contamination, such as particles or residues left over from the laser-cutting or machining processes, can obstruct the gas flow channels or interfere with the coating applied to prevent corrosion. These impurities can cause a significant decline in cell performance, efficiency, and durability.

For fuel cells used in automotive applications, where reliability and longevity are paramount, precision cleaning is required. Even microscopic contaminants can hinder the electrochemical processes, leading to reduced power output or premature degradation of the cell.

Cleaning process of bipolar plates

In the image it is explain the process:

1) The Bipolar plates arrive from the production line and are depositated on the entry belt (red belt). This belt is motorized and speed is adjustable.

2) When the Bipolar plates enters the cleaning station, it is pressed down by a pneumatic cylinder that will keep it firmly against the driving belts (green belts). A matching plan (blue) will keep the plate flat and prevent it from being deformed by the pressure of the upper rolls.
The speed of the green belt is the same that the speed of the red belt. This speed is set up to the required quantity of plates that must be cleaned in 1 minute

3) If necessary, detergent is sprayed on the plate – In some cases detergent is not necessary, this depends upon the contamination of the plate, the speed, the required level of cleanliness

4) and 5) Steam is sprayed on the plate and suction is active to extract the steam. No steam comes out during the cleaning process

6) An air blade will remove the water droplets that have not been extracted by the suction

7) If necessary hot air is blown on the plate to make sure they are perfectly dry after cleaning

8) The bipolar plates are clean and dry and can be directed to the next operation

Photogallery