A curing step that takes seconds instead of minutes changes how a whole line is designed. UV curing equipment replaces thermal ovens and solvent flash tunnels with high-intensity ultraviolet light that fixes adhesives, coatings, and inks on demand, and choosing the right system starts with understanding how the three main formats differ.
How UV Curing Works
UV-curable chemistries contain a photoinitiator that fragments when it absorbs light at a specific wavelength, releasing species that drive polymerization. The reaction is fast, largely heat-free, and stops when the light stops. Because the material stays liquid until exposure, operators get unlimited open time to position parts, then lock the bond with a light dose measured in millijoules per square centimeter.
Two variables govern a successful cure: the peak irradiance at the surface, in milliwatts per square centimeter, and the total energy dose delivered over the exposure. Both must match the adhesive’s data sheet, and both should be verified with a radiometer rather than assumed.
Mercury Arc Versus UV LED
Conventional systems use a mercury or doped-mercury arc lamp that emits a broad spectrum from roughly 240 to 420 nm. They deliver high broadband intensity and cure a wide range of chemistries, but the bulb runs hot, has a service life measured in hundreds to low thousands of hours, needs warm-up and cool-down cycles, and its output drifts as it ages.
UV LED systems emit a narrow band, typically centered at 365, 385, 395, or 405 nm. They switch on instantly, run tens of thousands of hours, produce far less infrared heat, and hold stable output. The trade-off is that the chemistry must be formulated for the specific LED wavelength, and shadowed geometry gets no help from stray shorter wavelengths.
The Three Equipment Formats
Spot curing
A spot lamp delivers a focused beam through a lightguide or lens to a small target, often 3 to 12 mm across, at high local intensity. It suits precise, low-throughput work such as bonding small components, tacking wires, or fixing optical elements. The Incure L9000 UV LED spot lamp guide covers how lightguide length and working distance affect the dose that actually reaches the joint.
Flood curing
A flood lamp illuminates a larger area, from a few square centimeters to a full panel, with reasonably uniform intensity. It fits batch work, coated flat parts, and fixtures holding several parts at once. Matching the illuminated area and intensity to the part is covered in the Incure L-Series UV LED flood lamp guide.
Conveyor curing
A conveyor system moves parts under one or more lamp heads at a set belt speed, giving a continuous, repeatable dose governed by speed and lamp power. It is the format for automated, high-volume lines. Sizing the lamp head to belt speed and part width is covered in the Incure CDM UV conveyor guide.
Selecting a System
1. Start from the chemistry
Confirm the adhesive or coating’s required wavelength, peak irradiance, and dose. This determines whether a mercury or LED source is appropriate and how much power you need.
2. Size to throughput and geometry
Spot for precision and low volume, flood for batches and panels, conveyor for continuous production. Account for part height, since irradiance falls off with distance from the emitter.
3. Address shadowed areas
If the bond line is not in direct line of sight, plan for a dual-cure chemistry with a secondary moisture or heat mechanism, or add lamp heads at multiple angles.
4. Plan verification and safety
Budget for a radiometer, a maintenance schedule, and UV shielding or an enclosed chamber. Enclosed systems are covered in the Incure B/C-Series cure chamber guide. For help matching a lamp to your material, Email Us.
Common Problems
A tacky surface after cure usually means an underdose or an oxygen-inhibited skin on an open joint; raise the dose or blanket with inert gas. Cure that looks fine but has low strength points to a wavelength mismatch between lamp and chemistry. Output that has slowly declined without a process change points to an aging bulb or a fouled lightguide, both caught by routine radiometer checks. Yellowing of the cured film generally comes from too much infrared or an overdose on a heat-sensitive chemistry.
Frequently Asked Questions
Q: Can we switch an existing mercury line to LED?
A: Often, but the adhesive or coating must be requalified at the LED wavelength, and the fixture geometry may need adjusting because LED output is more directional. Treat it as a process change, not a drop-in swap.
Q: How often should the radiometer be used?
A: At shift start for critical bonds, and after any bulb, lightguide, or reflector service. Log the readings so a downward trend is visible before it causes rejects.
Working With Incure
Incure supplies UV LED and mercury-arc curing equipment in spot, flood, chamber, and conveyor formats, along with the UV adhesives and coatings formulated to run on them. Our specialists help you match the source, intensity, and format to your chemistry and throughput so the process is validated end to end. Contact Our Team to discuss your curing line.
Visit www.incurelab.com for more information.