Improving Surface Cure with UVC LEDs


Mike Kay, Excelitas

UV LED solutions have demonstrated the ability to successfully replace older mercury lamp solutions in a number of curing applications by providing reduced operational costs through longer lifespans, reduced electrical consumption, higher reliability and reduced heating of substrates. At the same time, formulation modification has enabled the use of an increasing number of UV LED curable adhesives, inks, and coatings for commercial applications. In a number of applications such as UV curable coatings, there are still limitations for UV LED curing, preventing wide commercial adoption. Among the available formulations, the variation in curing performance is quite large and surface cure remains the biggest challenge to overcome with LED curing. When using LED based light sources, additional exposure to deep-UV irradiation or curing under inert-gas blanketing is most often required to achieve a tack-free surface. Post exposure to deep-UV LEDs is an attractive solution that is investigated in greater depth to explore irradiance, dose and wavelength requirements for industrial curing solutions.  In addition, the feasibility of adding deep-UVC LEDs into a commercial LED curing system is also discussed.