UV LED Curing in Inkjet Printing Applications

Abstract

LEDs have many potential advantages as alternatives to traditional UV light sources for adhesive and ink curing. However, the application of LEDs for UV curing has not been as successful as expected by many researchers, despite the many attractive features LED technology provides. The high cost of UV LEDs is often cited as the primary reason for why they are not widely accepted in the industry.Based on our understanding of LED technology, we have compared the performance of LED based light sources with traditional UV light sources and addressed the technical issues such as spectrum and light intensity needed for UV curing applications.While much effort is still needed to successfully use LEDs in full-cure applications, recent work between EXFO and key digital print partners has shown that LEDs will improve the quality of digital printing. Print quality is controlled through an intermediate stage called ‘pinning’, where UV ink is partially cured on the print media. At this stage, LEDs have many advantages compared to traditional UV light sources. The improvements in print quality including enhanced image resolution, color depth and color clarity have been discussed.