Gasketing
Gaskets provide correct compression and act as a ‘barrier’ for potential fuel leaks; maximizing the highest possible efficiency.
One of the important parameters in a fuel cell build is the thickness of the gaskets. The gasket thickness determines how much the flow fields are allowed to pinch into the electrode. For a good contact (i.e. low contact resistance), it is essential that the values are 0.002” to 0.003” for a carbon paper backing and 0.010” to 0.015” for a carbon cloth backing*. Since electrode thickness for anode and cathode may vary, gasket thickness for each side is determined separately using the formula: Gasket thickness = (individual electrode thickness) – (desired pinch)
* These numbers are provided for guidance only. It is better to determine the pinch for individual situation with due consideration for the type of backing used and the nature of the gasket material (elastomeric materials, e.g. EPDM, tend to compress more than non-elastomeric films, e.g., PTFE)