The Look of Glass: Getting Smooth, Clear UV Coating Again!
With every year that passes, I sound more and more like my father while having discussions with my three daughters. I start sentences with the phrase: “When I was younger...” Or, use the expression “good old days” just as he used to say when I was growing up.
Professionally, I’ve been feeling nostalgic when it comes to the smooth, deep look of UV coating. Back in the day, when I first became involved with UV printing, we had a press with a two-roller coating system. These systems allowed the pressman to apply as much coating as needed for the job. The two- and three-roller coating systems also made the coating look as deep and smooth as a sheet of glass.
Then it all changed with the introduction of the new closed-chamber, anilox style coating units. They were sold by the OEMs as “pressman proof.” They enabled management to have the ability to make sure that all of the pressmen apply the same amount of coating regardless of the individual or knowledge level.
How many of you are familiar with the term microfoaming or microbubbles? This is the direct result of air being trapped in a roller's empty cell as it attempts to refill with UV coating. This inhibits the coating from laying even on the sheet without pin holes in the surface.
This condition appears instantly with some coating systems as the unit goes on impression and the press speeds up. You have no choice but to either run with these imperfections, add leveling agents to the coating to assist with reducing the foaming issues, or as the surface degenerates, change the barrel of coating out prematurely to a new barrel while setting the foamed up coating aside until the tiny bubbles dissipate.
Back in the spring, I had another opportunity to write up the specifications of a new printing press that we equipped for my customer’s needs. Having the ability to use vendors for the auxiliary equipment that I have had the most experience and success with, I reached far outside the box.
I specified the machine with a coating unit that, until this request, had not been installed on any of this OEM’s machines delivered here in the United States. I’m sure that I don’t have to tell you about the eyebrows that were raised or the phone calls that I received early on, but the requests were fulfilled and the machine delivered early last month. It is now up and running.
I was recently on site to initiate the UV application and process training along with the UV production start up. Let me say this; regardless of the press speed, sheet size or substrate, the coating looked and felt as smooth as a sheet of glass with not a bubble in sight. The results were outstanding.
Knowing how “out of the norm” this request had been, I want to thank everyone involved for their support throughout this order and delivery. A satisfied customer is priceless.
Personally, I can’t tell you how good it felt to see coating like in the “good old days” again.
We all know how printing can be a high-pressure business, but remember, there are times when pressure is a great thing.