The difference in UVA UVB UVC
Light-emitting diodes (LEDs) can be manufactured to emit radiation in the ultraviolet range. In 2019, following significant advances over the preceding five years, UVA LEDs of 365 nm and longer wavelength were available with efficiencies of 50 percent at 1000 mW output. Such LEDs are increasingly used for UV curing applications, and are already successful in digital print applications and inert UV curing environments. Power densities approaching 3 W/cm2 (30 kW/m2) are now possible, and this, coupled with recent developments by photoinitiator and resin formulators, makes the expansion of LED-cured UV materials likely.