Ultra-violet printing is not a new technology. As a matter of fact it has been utilized with great success for more than a decade in the flexographic printing industry. UV printing provides a higher quality print as compared to water-based or solvent ink systems. With a UV flexo-printer the 100 percent solid ink can be comprised of oligomers, monomers and photo-initiators that “when exposed to intense ultraviolet light provide outstanding durability, chemical resistance and graphic brilliance well beyond that of water or solvent ink systems.”
UVA, UVB, UVC and UVV wavelength outputs through medium pressure mercury vapor lamps help the flexo ink system operate. UV flexo inks are poured into ink fountains which then makes them easy to transfer to the anilox, plate cylinder and a printers’ substrate. On the technical end of the spectrum, the “UV flexo process requires that a 400 WPI UV curing unit be placed directly after each print station.”
Following the transfer of the ink to the substrate, UV light is shone to expose the photo initiators in the ink system which then turn into “free-radicals;” this means they will seek out the monomers and oligomers, adhere to them and perform the printing task. UV flexo ink provides a print quality that is prized for its ink density and the high quality of its graphics printing.
Some other advantages and benefits of an UV flexo printer include:
- Better half-tones
- Less dot-bridging
- Higher solid ink densities
- More reproducible color from run to run
- Because the ink does not dry on the printing plate it leads to a cleaner print during long run printing tasks
- This technology doesn’t need clean up during print project changes
- There is less downtime
Many who use the UV flexo printers find they are reaping higher quality in their print tasks; in some cases these printers rival the speed of offset printers.