This blog is the first of a three-part series discussing the positive attributes of UV-curable ink technologies as presented in a panel discussion at IT Strategies’ Digital Packaging Summit by Mike Barry, Fujifilm Product Marketing Manager – Digital Solutions.
How does UV-curable inkjet technology work?
The basic make-up of UV-curable inks consists of four components: monomers, oligomers, pigments and photoinitiators.
The monomers provide a building block of the ink and can contribute certain properties such as softness/hardness of the ink when cured as well as flexibility or elongation characteristics of the ink for varying types of applications. Monomers also help control ink viscosity which is essential to jetting reliability.
The oligomers in the ink formulation consist of reactive resins and uniquely formulated adhesive components for printing on particular substrates.
The pigments provide the color. However, the pigment dispersion is a critical component of the UV ink make-up as the particles need to be ground to less than 200 nanometers (one-fifth the size of a human nerve cell process) to fully develop color, with each nano particle coated to prevent agglomeration (clotting). Particles that are too large or agglomerated would compromise jetting accuracy, resulting in unacceptable print quality. Essentially all inkjet inks, whether UV or aqueous, need to be nano-sized to jet reliably and provide precise drop placement to optimize print quality.
“The R&D and quality control in the manufacturing of inkjet ink is crucial to achieve the incredible color consistency and print quality delivered by today’s digital presses.” — Mike Barry, Fujifilm Product Marketing Manager – Digital Solutions
When the photoinitiators are exposed to UV light, the oligomers and monomers cross-link or polymerize. So unlike aqueous or water-based inks, no heat or air drying is required for curing. But even the photoinitiators need to be tuned to a specific wavelength of UV light so curing can be accomplished by UV or UV-LED lamps.
For a more intensive review of Fujifilm UV-curable inkjet inks for packaging, visit Fujifilm Packaging Insights.
In the UV Ink Series 2, we’ll answer the question: What makes UV-curable inkjet technology a good fit for packaging printing?