There have been more than 500 retrofits or installations of LED UV technology around the world, consultant Richard Wilson told the British Coatings Federation’s Shining the Light on LED UV in Edinburgh last week.
The event gets a second run out in Sutton Coldfield tomorrow (Tuesday). “All the main press manufacturers support the technology,” he said, explaining that UV LED has been fitted to presses across the range from narrow web to a Heidelberg Speedmaster XL162. “And it will break into packaging,” he added. “It has already done this with web offset where the printers have now turned off their conventional dryers and are running UV LED with no emissions.”
However, there is still a knowledge gap across the industry. Consequently printers are each feeling their own way to success, making the process longer than it needs to be. “We need best practice guidelines: the tolerance for running a litho press is a lot tighter than with conventional inks. UCR is essential: ink coverage should be no more than 320%. This is because UV inks can feed back and blend into the yellow.”
To remedy this he suggests that printers consider changing the lay down sequence of inks and keeping a close check on density measurements which will also differ from those a printer may be used to. Matched fount solutions, roller coverings and blankets are essential.
And while one of the benefits of running with UV is that it becomes much easier to print on uncoated papers and non standard substrates, it is not automatically win-win for rougher papers where there can be abrasion of the surface or on silk papers where the coating my flake from the paper. A lick of seal will stop this.
“Don’t just buy a lamp unit, put it and run because you will come up against problems,” said the consultant who has been adviser on a large number of retrofit projects.
His views were endorsed by the experiences of two printers present, both of whom cautioned against any exception that UV LED meant saving money. B&B Press was the first in the UK to install a new LED UV equipped press and now has four- and five-colour Sakurais with the technology. Sales and marketing director Dave Stones described benefits including a wider colour gamut, reducing the need for spot colours; the ability to sell on quality to luxury brands and helping an envelope converter by being able to print on bond paper and return a job without a lengthy period waiting for the sheets to dry.
J Thomson Colour managing director Kevin Creechan echoed this saying that its analysis before investment could not clearly justify the investment in a six-colour press. “We ended up taking a leap of faith,” he said. “If we had put in a standard press would we have been behind the market when we came to replace it in seven years' time?
“It has taken time to get there, but the best we have done is invest in that press.”