54 formulations is the low glass transition temperature, which ensures high tear resistance, long-lasting elasticity and resistance to temperature changes – essential when cold-starting fuel cell systems. In hollow-fibre membrane humidifiers, bundles of tubular membranes are potted into a support tube at both ends – a principle familiar from water filtration. The resins must penetrate between the hollow fibres and ensure sufficient wetting of the bundle without clogging the individual fibres. For this reason, potting compounds have been designed for optimal exothermicity. The heat generated during the reaction between the resin and hardener is controlled, thereby effectively preventing oxidative damage to the sensitive membrane tubes. At the same time, the 2K polyurethane systems are hydrophobic and prevent a reaction with the moisture contained in the membrane material and consequent bubble formation. For processing and application, the properties of the adhesive such as viscosity and pot life can be customised to meet individual requirements. Curing usually takes place at room temperature, but to accelerate manufacturing cycles, it is also possible to use thermal curing in a convection oven or via infrared radiators. The two-component systems can also be used for other applications in humidifiers, such as for sealing and bonding housings, for seals on water inlets and outlets, for sealing and bonding bypass valves and for creating internally sealed zones. UV curing High-performance, light-curable materials streamline bonding, masking and sealing steps in fuel cell manufacturing. The materials can be formulated for assemblies exposed to elevated temperatures and aggressive operating environments, maintaining dimensional stability and adhesion when used with metals, ceramics and composite substrates. The instant UV and visible light curing minimises thermal load, and enables precise control of bond-line thickness and gasket profiles, improving process consistency and repeatability. These materials are formulated without solvents to prevent contamination of active cell layers and reduce outgassing, supporting stable long-term cell performance, and they are compatible with multiple operations, meaning that the same curing platform can be used for structural attachment, edge sealing and protective masking. This simplifies process design and reduces cycle time through an integrated approach that supports automated assembly and quality validation. These capabilities help engineers increase throughput, and maintain mechanical and chemical reliability in demanding fuel cell applications. Applying the material Fuel cell manufacturers face a key challenge in sealing individual cells, which is a slow, energy-intensive process that directly affects the stack’s lifetime and reliability. Traditional methods involve long curing times and complex workflows, making them unsuitable for industrialscale production. Delo and Datron have jointly developed a fully automated, highspeed sealing system. This combines Delo’s fast-curing liquid sealant and UV technology with Datron’s high-precision dosing system. At the heart of the system is Delo’s Photobond SL sealant, which has been developed specifically for fuel cell applications. This is applied directly as a liquid gasket and cures in seconds under UV light. The process is enabled by the Datron evo 600 system, capable of dispensing at up to 50 m/min. The volumetric dosing control ensures a consistent bead profile, even at start and stop points. Two key features ensure the inline quality assurance: an integrated confocal sensor that measures bead height immediately after dispensing, and the fluorescent properties of the sealant, which allow optical quality checks in real time with a closed-loop monitoring system. Together, these elements create hundreds of precisely Deep insight | Fuel cell adhesives January/February 2026 | E-Mobility Engineering The Datron evo 600 system uses Delo adhesive materials (Image: Datron)
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