A UV curing conveyor is meant to cure with light, but the lamp, the housing, and the parts all carry heat. On heat-sensitive substrates and thin plastics, how that heat is managed decides whether the part leaves the conveyor cured and flat or cured and distorted.

Q: How do you control heat on a UV curing conveyor?

A: Choose a lamp head and intensity no higher than the process needs, keep the cooling and exhaust paths clear, set belt speed and lamp height so parts spend only the required time under the lamp, and pick a belt material suited to the part temperature. Then measure part temperature at the exit rather than assuming it.

Where the Heat Comes From

Three sources contribute on a conveyor:

• The lamp head. Incure’s CDM™ conveyor uses forced-air cooling, and its mercury-arc heads also require exhaust ventilation. Dual-head x2A configurations add the thermal load of a second head.
• The exposure itself. Time under the lamp is set by belt speed. A slower belt delivers more dose and also more time in the cure zone.
• The cure reaction. Many UV adhesives and coatings release heat as they polymerize, so thick deposits can warm independently of the lamp.

Parts can also arrive warm from an upstream process, adding to all three.

Step 1: Do Not Over-Specify Intensity

The simplest way to reduce heat is to avoid more lamp than the adhesive needs. Incure’s own configuration notes describe the F400 and F500 arc tiers as carrying higher heat load than the F200 tier, and suggest the F200x2AC as a proportionate step for lines that have outgrown the F100x2AC without needing more. The same logic applies across the platform: confirm the dose the adhesive requires, then choose the configuration that meets it with margin rather than the highest-output head available.

For LED applications, the choice between flood and focused beam also matters. A focused-beam head such as the M51 exposes only a 1-inch strip, so components outside that strip receive no UV. Incure positions focused-beam heads for assemblies with heat-sensitive or pre-bonded neighbors next to the bond line.

Email Us with your substrate, part thickness, and required dose, and Incure can suggest a CDM™ configuration that cures without unnecessary exposure.

Step 2: Keep Cooling and Exhaust Working

Cooling only works if air can move. Keep intakes clear, inspect filters on a fixed schedule, and confirm exhaust ventilation for arc heads is sized for the configuration installed — particularly when moving from a single-assembly x2AC head to a dual-head x2A. Incure flags the second head’s added thermal load as a facility consideration on lines without existing high-capacity ventilation.

Step 3: Balance Speed and Dose

Belt speed on the CDM™ runs from 1.5 to 12.0 ft/min. Running slower than necessary adds exposure time without adding cure benefit once the adhesive is fully cured. If parts run warm, first check whether the belt is set slower than the qualified dose requires; restoring the correct speed is a zero-cost fix.

Where a process genuinely needs more dose, adding dose without adding time is often possible on the arc platform: the x2A configurations double the dose of the matching x2AC at the same belt speed. As a hypothetical, a part that needs 4,500 mJ/cm² UVA could run on the F200x2AC at about 3 ft/min, or on the F200x2A at 6 ft/min, where Incure publishes 4,500 mJ/cm² UVA. Whether that reduces part temperature on your line must be measured, since the second head also adds heat.

Step 4: Choose the Belt for the Part Temperature

The standard CDM™ uses a 9-inch polypropylene belt. Incure notes that a solid polypropylene surface can trap heat or residue against the part, and positions the CDM™ Compact’s 9-inch stainless-steel wire belt for higher-temperature parts. The Compact supports only the F400 and F500 heads, so this option applies when those heads already fit the process.

Step 5: Measure at the Exit

Part temperature is a measurement, not a calculation. Check it at the conveyor exit on representative parts, at the production speed and height, and after the lamp has run long enough to reach steady operation. Record the result with the product recipe. If temperature is too high, change one variable at a time — intensity, speed, height, or cooling — and measure again.

Arc Start-Up and LED Behavior

Mercury-arc lamps have a warm-up and cool-down cycle, so arc heads tend to stay running through short stops. LED heads have no warm-up delay and accept PLC, RS-232, and foot-switch control, which makes it practical to turn the head off whenever no parts are present and avoid heating an empty cure zone.

When Heat Points to a Different Approach

If a substrate still distorts after intensity, speed, cooling, and belt have been optimized, consider whether the bond needs a narrower exposure, such as a focused-beam head, or whether the joint design and adhesive selection should be revisited. Incure’s discussion of how CTE mismatch causes adhesive bond failure covers the thermal-stress side of that question.

For conveyor fundamentals, see the industrial guide to curing conveyors, and for each head’s output and ventilation requirements, the CDM™ lamp-head guide.

Contact Our Team to review heat management on your conveyor line.

Visit www.incurelab.com for more information.