UV Curing has definitely found its niche in the offset printing market and there are plenty of suppliers out there (ex. Eltex, Prime UV, GEW, and IST to name a few) In this entry, I give you the perspective of a pressman who has actually seen a UV curing system integrated onto a coldset offset printing press. Coldset printers who want to start competing in the heatset printing market can make quick inroads with comparatively small modifications to their press line and this was no less true for our company. There are however some realities that you must be aware of from an operational standpoint.
Why Some Purchase A UV Ink System
What you will hear when debating whether to purchase this system is the cost analysis perspective. Is it worth it to make the comparatively small intitial investment of purchasing a UV drying system as opposed to buying a heatset oven? This is a complicated analysis and I do not offer such in this entry. What I can tell you is what we have experienced when implementing such a system onto our Goss Community press line. What I present is from an operational standpoint as opposed to one that examines cost. I hope this angle will give you the insight you need when deciding whether or not to go with heatset drying or UV curing.
Here are five things you should know.
1. Count on narrow ink and water balance window. The jury is still out on whether this can be resolved. This was the first painful learning curve when implementing our system. The ink and water balance window is much tighter, so expect more waste. We were promised less start up waste, but I never saw this. This will be an ongoing cost that must be factored. Time will tell if this can be improved, but I have found it much easier to balance and troubleshoot coldset and heatset printing inks.
2. New Consumables Must Be Implemented. Rollers, blankets and blanket washes all have to change. Count on these consumables costing about 20% more. They must be more resistant to the chemical of the UV ink.
3. Not All Paper Types Print Well. UV inks definitely give more vibrant colors and our color gamut increased notably as promised. Such are the benefits of in line drying. However the ink does not lay down well on all paper stocks in the newsprint category. If you have a paper that you dominantly print on, I would insist on seeing a sample printed somewhere to ensure your finished product will look right.
4. We Had To Replace Our Ink Pumps. This was not a surprise as we had been warned about it. UV ink, under pressure, will harden. That does not bode well for conventional ink pumps. Count on purchasing new pumps.
5. Health Issues. While some of the pressmen had a sensitivity to the various solvents and ink that we had been using, this problem seemed to worsen after handling UV inks. Some developed a rash if they had prolonged exposure to regular heatset inks, however exposure to UV inks caused an immediate reaction. I don't take any chances with the stuff. Count on wearing gloves all the time and wash your hands immediately after using it. This one of the hazards that must be evaluated when purchasing such a system.
Any other concerns, I found the company that supplied the UV curing system openly conveyed to us. I merely try to present it from an operational perspective. There are many advantages of printing with UV inks, but I think anyone that pushes those products will do a good enough job of selling you on the idea. If you have any observations of your own, please leave a comment below and share it.
Bill,
ReplyDeleteI have heard from other sources too that the water window is small with UV inks. This does not have to be the case in the future.
In testing a prototype concept for positive ink feed with EB inks and with UV inks, the water window was made to be quite large. So potentially a small water window will not always be problem for these types of inks.