Bipolar plates straightening machine for serial production
- For the first time, the Graebener® Straightening Machine enables you to produce flat bipolar plates – a necessary requirement for both economical stack production as well as high performance and durability of the stacks.
- The machine can be operated either as a single machine or as part of a fully automated production line.
- Thanks to Graebener’s in-house production laboratory, they determine the corresponding process parameters in advance in a prototyping.
- How warping occurs:
- In the production of metals and in their further processing, residual stresses are introduced.
- With very thin material thicknesses, as is the case with metallic bipolar plates, these residual stresses become particularly visible.
- In addition, the complex three-dimensional geometry of the bipolar plates leads to a further asymmetrical distribution of residual stresses.
- As a result, metallic bipolar plates always contain a certain residual stress despite all technological and process precision.
- This shows up in the form of warping or deviation from an ideal flatness.
- Advantages of straightening: More efficient and economical stacks
- For use in fuel cells and electrolyzers, metallic bipolar plates are stacked and pressed together in stacks of sometimes several hundred plates.
- In addition to the bipolar plates, extremely flexible and sensitive components such as membranes, gas diffusion layers and seals are also installed.
- If the bipolar plates are not flat but warped, this leads to an inhomogeneous distribution of pressure between the components when a stack is pressed together, which has a negative impact on the effectiveness and durability of the stack.
- If the resulting transverse forces are too great, this even leads to microcracks in the sensitive components, and total failure of the stack can occur.
- Warped bipolar plates also reduce the overall economic efficiency of stack production, as they require more effort in all processes following the welding process, i.e. in seal testing, post-coating, seal application and stacking.
- Contactless straightening: Highest quality with full flexibility
- With this specially developed and worldwide unique technology for straightening metallic bipolar plates, these residual stresses can now – depending on the geometry – either be significantly reduced or even almost completely eliminated.
- Bipolar plates straightening machine is designed in such a way that the straightening process is contactless.
- Thus, it neither influences the surface and a possible coating nor the moulded geometry of the metallic bipolar plates.
- Furthermore, the bipolar plates straightening machine can be used for all metallic single and bipolar plates, without geometrical restrictions in the X and Y directions.
Key features
- Elimination of warping respectively residual stresses.
- Prevention of inhomogeneous pressure distribution between the individual components of a stack : stacks with higher effectiveness and durability.
- Reduction of the effort in all processes following the welding process (i.e. in seal testing, post-coating, seal application and stacking) : more economical stack production.
- The machine can be operated either as a single machine or as part of a fully automated production line.
Application areas
- Production of metal bipolar plates for fuel cell application
- Production of metal separator plates for electrolysis application
- Production of metal bipolar plates for heat exchanger application
Contact us
- Let us help you out in getting the most efficient production lines for serial production of Bipolar Plates production. Interested? Please contact the vendor by filling in the contact request form.
