UV LED Curing for Formed-in-Place Gasket (FIPG) Sealing

A formed-in-place gasket is not a part that gets fitted — it is dispensed as a bead of liquid directly onto the component and cured where it lies. Doors, hoods, battery pack trays, control-unit housings and electrical enclosures are all sealed this way, because the bead follows whatever path the flange takes and there is no cut gasket to stock, position or get wrong.

The materials normally used slow the line down. Two-component gaskets need metering, mixing and pot-life management, and they foul the dispensing head. Moisture-cure materials are simpler to dispense but cure from the outside in at the speed the ambient humidity allows, which can mean hours of racking before the part can be handled — floor space and work-in-progress that a takt-time line cannot absorb. Neither gives a bead whose height and density are the same on the first part of the shift and the last.

A one-component UV-curable foam gasket removes the mixing and the wait. The robot plasma-treats the flange to raise the surface energy, dispenses the bead, and a UV LED head mounted on the same robot or over the conveyor cures it inline at 395 nm. The material supplier reports a cure of roughly one second to a depth of up to 5 mm, with the material expanding up to 4.3 times as it foams, so less material fills the same gap.

From the ETIA catalogue the cure head is the OmniCure AC Small series: the AC4 at 365/395 nm delivering 8 W/cm² across 50 mm and 75 mm lengths, or the AC5 at 395 nm delivering 14 W/cm² air-cooled at flexible working distances and in any mounting orientation — which matters when the head has to ride on a robot arm rather than sit over a flat conveyor. The specific width and irradiance depend on the bead geometry and line speed, so ETIA sizes the head against the actual part.

OmniCure® AC Small (AC4 / AC5) is recommended for formed-in-place gasket curing: 395 nm output matched to one-component UV foam gasket chemistry, air-cooled with no chiller, and mountable in any orientation for robot-carried or conveyor-mounted inline cure.

As an authorized OmniCure® distributor, ETIA supports application review, product selection, genuine supply, installation, training, troubleshooting, and long-term service.

ETIA helps customers translate UV curing requirements into practical, reliable production solutions.