Hydrogen fuel cells are moving from prototypes to commercial vehicles, backup power systems, and stationary energy units. Inside every stack are hundreds of individual cells that must remain perfectly sealed. Without the right gasketing, fuel and air can leak, water can collect where it shouldn’t, and the entire stack can lose performance or fail prematurely.
Why Fuel Cells Depend on Gaskets
A PEM (proton exchange membrane) fuel cell makes electricity by splitting hydrogen at the anode and combining the resulting protons and electrons with oxygen at the cathode to form water. For that reaction to run safely and efficiently:
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Hydrogen and air/oxygen must remain isolated; even tiny cross leaks waste fuel and can create flammable mixtures.
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Pressure and flow need to stay consistent across all cells; leaks cause uneven performance and localized damage.
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Water must be carefully controlled — enough to keep the membrane hydrated, but not enough to flood channels.
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Electrically conductive plates have to stay isolated to prevent short circuits.
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The stack is compressed under load; seals must hold through thousands of pressure and thermal cycles.
Materials That Work in Fuel Cell Environments
Closed Cell Silicone sponge
Closed-cell silicone sponge (such as R10480 Silicone Sponge) resists heat, humidity, and chemicals while maintaining flexibility. Excellent for perimeter and manifold seals where you want low leak rates and long-term resilience.
Closed Cell Silicone foam
Medium and firm silicone foams like HT-800 offer stable compression set and reliable environmental sealing — ideal for repeatable stack compression and long-term outdoor or under-hood conditions.
Viton® (FKM) solid elastomer
Viton is a fluoroelastomer known for exceptional chemical resistance and thermal stability. It withstands continuous exposure up to about 200 °C (short excursions even higher) and is largely unaffected by fuels, oils, solvents, and aggressive coolants. In a fuel cell context, solid Viton is valuable where the seal might see hydrocarbons (in reformer-fed systems), aggressive cleaning chemicals, or very high temperature and pressure.
Viton® sponge
Viton sponge is a closed-cell version of FKM. It retains the chemical and temperature resistance of solid Viton but with a compressible cellular structure, making it easier to seal under lower bolt load and to fill irregular gaps. Viton sponge is especially attractive for manifold seals and stack frames where aggressive chemicals or coolants could degrade standard silicone, but where a softer, conformable material is still needed.
Expanded PTFE (ePTFE)
Expanded PTFE is PTFE stretched under controlled conditions to form a microporous structure. This creates a chemically inert, soft, and highly conformable gasket that seals at very low compression force and resists creep. In fuel cells, ePTFE is often used as a thin sealing interface around MEAs and flow fields.
Graphite composite seals
Sometimes used in high-temperature fuel cell types (like solid oxide), graphite offers excellent thermal stability and conductivity control.
Adhesive Systems That Support Assembly in Fuel Cells
To make these materials easy to handle, pressure-sensitive adhesives can be laminated to the foam or rubber:
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3M 9472 — reliable for silicone bonding.
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3M 9485PC — high-temperature acrylic adhesive with strong long-term hold.
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3M 467MP — popular for bonding to metals and high-energy plastics in manifold areas.
Using adhesives simplifies production: gaskets stay put during stack build, and sealing lands are precisely located.
Converting for Precision and Repeatability
At NEDC we convert/die-cut and precision cut silicone sponge, silicone foam, Viton, Viton sponge, ePTFE, and other engineered materials into ready-to-install gaskets and adhesive-backed seals. Complex flow field geometries, thin sealing webs, and perimeter frames can be produced with tight tolerances. Parts arrive to the customer clean, cut to print, and ready for direct stack assembly.
Summary
Fuel cell reliability depends on controlling gases, pressure, and moisture inside the stack. Silicone sponge and silicone foam remain go-to choices for long-term sealing, while Viton and Viton sponge add aggressive chemical and temperature resistance where it’s needed. Advanced materials like expanded PTFE offer extremely low leak rates and excellent conformability. Combined with proven adhesives and precision converting, these materials allow manufacturers to build safe, efficient hydrogen systems with confidence.