The fixture is the most overlooked component on a UV cure conveyor. It sets part height, holds the bond line in the beam, decides what gets shadowed, and rides through the cure zone thousands of times — yet it is often designed after the conveyor is already on order.
Q: Do parts on a UV cure conveyor need fixtures or carriers?
A: Not always, but any part that can shift, tip, or present its bond line inconsistently should ride in one
Flat, stable parts with exposed adhesive can sit directly on the belt. Parts that roll, sit at an angle, carry adhesive on a narrow seam, or vary in orientation need a carrier that locates them the same way every pass. The carrier then becomes part of the optical setup: it changes the working distance, it can cast shadows, and its material has to tolerate repeated UV exposure and the belt environment.
Rule 1: Account for Carrier Height in the Working Distance
Published irradiance is measured at a stated working distance — 2 inches for the UV LED heads on the Incure CDM™. A carrier lifts the part, so the bond surface ends up closer to the lamp than the belt height suggests. Curing height adjusts from 0.5 to 2.0 inches on the LED heads and from 3.0 to 6.5 inches on the F400/F500 arc heads; set it from the bond surface in the carrier, not from the bare belt.
Consider a hypothetical carrier that raises the bond surface 0.75 inch above the belt, with the lamp set 2.0 inches above the belt. The bond now sits 1.25 inches from the lamp (2.0 − 0.75), not at the 2-inch reference distance where the irradiance figure was measured, so the delivered intensity will not match the data sheet. Measure at the bond position in the loaded carrier, and qualify the process at that real distance.
Rule 2: Keep the Bond Line Inside the Beam
Flood heads forgive small position errors; focused-beam heads do not. The M51 exposes a 1-inch-wide strip and the M62 a 2-inch strip, by design, so components outside the strip receive no UV. A carrier for a focused-beam line must hold the seam inside that strip on every part. Flood heads have their own limits: the L64’s 6″ × 4″ footprint is sized for a 4-inch panel lane, and the L88 clears parts up to 8 inches wide. A carrier that positions a part partly outside the rated width will under-cure the overhanging edge.
Email Us with a sketch of your part and proposed carrier and Incure can check it against the head’s beam footprint and curing height.
Rule 3: Design Out Fixture Shadows
Every wall, clamp, or locating pin taller than the adhesive can block light arriving at an angle. Practical habits:
- Keep locating features below the bond surface wherever possible.
- Chamfer or open the walls on the sides facing the lamp.
- Place clamps on surfaces with no adhesive nearby.
- Check exposure with photosensitive indicator paper placed at the bond position inside the loaded carrier.
Rule 4: Choose Carrier Material for the Environment
The carrier sees the same UV, heat, and cleaning cycle as the belt. On the CDM™, the belt choice already signals the environment: the standard chassis uses a 9-inch polypropylene belt, with an anti-static option for parts that need it; the CDM™ Compact uses a 9-inch stainless-steel wire belt for higher-temperature parts, sharper-edged fixtures, and wash-down or solvent exposure a polymer belt would not survive long term. Match the carrier to the same conditions, and note that a reflective carrier surface can raise local dose compared with a matte one — published curing-energy figures already vary with working distance, part height, and reflectivity.
Rule 5: Make Loading Repeatable
A carrier only helps if it is loaded the same way each time. Add keyed features so the part cannot sit in the carrier backwards, mark the bond-side orientation, and make the carrier’s footprint fit the belt so it tracks straight. If the cell uses an LED head, the carrier can also carry a feature a part-present sensor can detect, letting the PLC switch the lamp only when a loaded carrier arrives.
Validating a New Carrier
Before production, run a short trial: place a radiometer probe at the bond position in the carrier, pass it through at production speed, and compare the reading with the same measurement on the bare belt. A large difference points to working distance or shadowing. Then cure sample parts at production speed and verify them with the adhesive supplier’s cure test. Record the carrier revision alongside the belt speed and curing height so later changes are traceable.
Lamp-head footprints and curing heights for every configuration are listed in the Incure CDM™ UV conveyor guide. For the general case for conveyorized curing, see the curing conveyor industrial guide, and for the LED flood array used on the L64 and L88 heads, the Incure L-Series™ LED flood lamp guide.
Contact Our Team to review carrier design for your UV cure conveyor.
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