UV-Curing Form-in-Place and Cure-in-Place Gaskets

  • Post last modified:September 2, 2026

Form-in-place and cure-in-place gasketing replace a cut rubber part with a liquid bead dispensed and cured directly on the component. Done with a UV-curable material, the cure takes seconds instead of hours, which is what makes the method practical for volume production.

FIPG and CIPG: The Difference

Form-in-place gasket (FIPG): The seal bead is dispensed onto one flange and cured before the mating part is assembled. The result is a fully cured elastomer gasket attached to one half of the joint. The parts then bolt together, compressing the cured gasket like a conventional seal.

Cure-in-place gasket (CIPG): Similar dispensing, but the emphasis is on the gasket being a permanent, adhered feature of the part, cured in place as a functional component rather than a consumable. In practice UV FIPG materials serve both roles, since they cure fully and quickly on the flange without needing the second part present.

Both approaches share the same advantages over die-cut gaskets: no pre-cut inventory, no scrap skeleton, no seam leak paths, an exact fit to any flange path, and consistent bead volume from an automated dispenser.

Why UV Cure

Room-temperature-vulcanizing silicone FIPG needs minutes to hours of skin and cure time, tying up the part and limiting line speed. A UV-curable FIPG cures on demand: dispense the bead, pass it under a lamp, and it is a handleable gasket in seconds. That collapses work-in-process and lets the gasket station keep pace with the rest of the line.

Incure Uni-Seal 6322

Incure’s Uni-Seal 6322 is a UV-curable form-in-place gasket and sealant. It serves as both a gasket and a sealant in one material, and cures very fast under low-energy LED lamps, which suits high-volume production. Its properties for enclosure sealing:

  • Air-tight seal with excellent conformance to the flange surface.
  • High resilience and flexibility, with good elastic memory so the gasket recovers after repeated compression cycles, outperforming many conventional cut gaskets on recovery.
  • Moisture and temperature resistance for demanding service environments.
  • Chemical resistance, which is why the material is widely used in electronics and automotive enclosures exposed to oils and process fluids.
  • 100 percent solids with no solvent, so there is no shrinkage from solvent loss and no VOC handling.

For a recommendation on bead size and cure setup for your flange, Email Us with the enclosure drawing and production rate.

Designing the Bead

  1. Compression target. Size the dispensed bead so it reaches 20 to 40 percent compression at assembly. Too little and the seal is marginal; too much and the gasket fatigues early.
  2. Groove or hard stop. A retaining groove positions the bead and limits compression. On a flat flange, design a metal-to-metal hard stop so bolt torque cannot crush the gasket.
  3. Flange rigidity. Keep bolt spacing close enough that compression stays even between fasteners. A flexible flange bows outward mid-span and opens the seal.
  4. Path tie-in. Program the dispense path to overlap cleanly at the start and end with no thin section.

Curing

Dispense, then cure under a UV source matched to the flange size. A UV LED flood lamp handles bench-scale parts; higher volume runs on a conveyor system. Verify the delivered dose at the bead with a radiometer against the data sheet. A tall bead cross-section can shadow its own base, so expose from more than one angle if the bead is deep. Watch for an oxygen-inhibited tacky skin on the exposed surface; a higher surface dose or an inert purge resolves it.

Validation

  • Compression set after aging at maximum service temperature.
  • Leak test at design pressure, before and after thermal cycling.
  • Thermal cycling across the service range, checking that differential expansion between the gasket and flange does not break the seal.
  • Fluid immersion in the specific chemicals the enclosure contacts.

Dispensing Equipment

A repeatable FIPG bead needs metered dispensing, not a hand-held cartridge. Progressive-cavity pumps and volumetric piston dispensers both deliver a consistent volume per unit length regardless of material pressure changes. The dispense head is carried on a gantry or robot that follows the programmed flange path at constant speed and needle standoff. Material temperature is held constant, since a 5 C change in resin temperature shifts viscosity enough to alter the deposited bead width. A vision check after dispensing, before cure, catches skips and thin spots while the bead can still be corrected.

Integrating the Cure Step

The cure lamp can sit at a fixed station the part indexes to, or travel with the dispense head a fixed distance behind the needle so the bead cures as it is laid down. Traveling cure shortens cycle time and prevents a long bead from sagging before it sets, but it requires the lamp and the dispense path to stay coordinated. A fixed station is simpler and fine for parts that hold their bead shape during the transfer.

FIPG Versus a Cut Gasket

A cut gasket is simplest for low volume and very large flanges. UV FIPG wins on medium-to-high volume, complex flange paths, and any case where seam leaks or gasket handling are a problem. It also gives tighter control of gasket volume and position than hand-placing a cut part.

Summary

UV-curable FIPG and CIPG give an air-tight, resilient, chemically resistant seal that cures in seconds and fits any flange path. Design the bead for correct compression on a rigid flange, cure to a verified dose, and validate with compression-set and leak testing. Incure supports formed-in-place gasketing end to end.

Contact Our Team to specify a form-in-place gasket process.

Visit www.incurelab.com for more information.