On the flexographic printing presses, inks are often solvent based. The process is simple, just apply an ink color, dry it with a hot air dryer, and then apply another color ink and so on. This process is optimized with facilities that take into account this need for drying.
But in recent years, new methods and new inks no longer require these thermal dryers.
How to work these inks without solvent?
These new inks are called EB or UV inks. These are inks dried with ultraviolet (UV) or Electron (EB) beams. The composition is quite different from the traditional inks because they do not include solvents, but the photo initiators which, in contact with UV or electrons, trigger a polymerase chain reaction. Specifically, the reaction is done in the space of less than a second and makes the ink dry almost instantly.
No need for thermal dryers between each station, but just a flash of UV or Electron beams at the end of print to be sure that all inks are frozen.
What are the advantages of these new inks?
The first advantage is of course, the loss of thermal dryers. This means less equipment, so less maintenance and risk of failure, and a higher printing speed. But because these new inks are also solvent-free, they are “greener”. In a perspective of sustainable development, these inks without solvents may be an interesting solution, especially since the laws on solvent inks have become more and more severe, and even though their main problem stands at the recycling and de-inking stage.
At IMS, we have made the choice of using UV drying inks with a flexographic press such as Mark Andy Performance Series P7. This way, we can offer an optimal result quickly, with more green inks and solvent-free.