There are still concerns among printers, converters and end-users about the health and safety and environmental profile of the process. These worries have dogged UV in Europe since it was first introduced approximately 30 years ago.
The biggest anxiety continues to be centered on the danger that components in UV inks, particularly photoinitiators, can migrate through packaging materials into food products.
To counter fears about the safety of UV, more care tends to have to be taken in ensuring that printers follow the correct procedures when using UV inks. As a result, producers of UV inks are having to provide a lot of technical support to their customers.
To ease the task of printers, equipment manufacturers have been developing monitoring tools and systems, including electronic controls, so that operating data can be collected and used as the basis for benchmarks.
In the longer term, the biggest challenge facing producers of UV inks, ancillaries and equipment could be the necessity to develop alternatives to the conventional mercury vapor curing lamps. Mercury is already classified in European Union regulations as a hazardous substance whose use in electrical and electronic equipment should be phased out.
One of the most promising new technologies is the UV curing of inks and varnishes with light emitting diodes (LEDs). However LED curing requires big changes in ink formulations.
Nonetheless, the use of LED equipment does offer the prospect of a UV process which ecologically will be an advance on conventional curing systems, particularly since it should be able to achieve considerable cuts in energy consumption.
A major impetus behind the expansion of UV into new printing sectors is the growing acceptance of its safety and contribution to environmental compliance, especially with the EU’s new regulatory restrictions on emissions of volatile organic compounds (VOCs).
“UV is regarded now as having the same risks as other major processes,” Klemens Ehrlitzer, managing director of the German label printers association (VSKE), said. “It is no more hazardous than using solvent- or water-based inks. With all these processes, the main requirement is that the printing is done in the right way.”
The improved image of UV among printers and converters has helped support demand for UV inks during the recession. Although sales have generally decreased in Europe, they have not fallen as sharply as those for other inks.
“There has been a slight slowdown in demand for chemicals for UV inks, but already there are signs of a turn-around,” said Steve Flaherty, a product manager at UK-based distributors Chance & Hunt, which sells UV ink raw materials. “Hopefully increased sales next year will pick up to such an extent that it will make up for this year’s small decline. What we see at the moment is a reflection of the underlying strength in demand for UV inks.”
UV Becomes Mainstream
UV has established itself in Europe as a mainstream printing process which can be applied across a broad range of sectors, even newspapers. It is seen as guaranteeing higher print quality without having to compromise health and safety rules.
“In the European narrow web sector, around 90 percent of printers are now using UV – in most cases as an alternative to solvent-based inks,” said Mr. Ehrlitzer.
UV inks have also been making rapid inroads into the inkjet printing segment in Europe, where printers consider them to be an effective alternative to solvent-based products and also a means of raising the quality of digital printing.
The visual impact generated by the colors and resolution of UV printing has been a powerful driver behind the demand for UV inks in packaging.
Brand owners are regarding the packaging of their products as an increasingly effective means for promoting their products. While the current revenues of advertising agencies are declining, those of agencies specializing in packaging are increasing, Thomas Reiner, chief executive at the German packaging consultancy Berndt & Partner, told a recent seminar in Berlin on packaging decoration organized by Zeller+Gmelin, Eislingen, Germany, specialists in UV ink production.
This focus on the promotional power of packaging is not only boosting demand for UV inks as a means of raising the quality of the graphics on packaging, but is putting pressure on printers to use them properly.
With food packaging, end-users not only want eye-catching graphics, but also a standard of printing which ensures that no chemicals can migrate through the packaging material.
“There has to be zero levels of failure with packaging,” said one ink company executive. “If something does go wrong, it is virtually always the fault of the printer or converter and not the ink manufacturer. If UV inks are applied and used properly, they are completely safe and will provide the highest printing quality.”
Health and safety agencies in Germany, the UK and other European countries have helped raise UV printing standards by issuing guidance on the correct handling of the inks and equipment during the printing process.
The production of food packaging, including the use of inks, is now covered by an EU regulation on Good Manufacturing Practice (GMP). The pharmaceutical sector also has a similar GMP code relating to packaging.
Ink producers themselves have been improving their inks and ancillary products to make the UV process easier for printers.
Sun Chemical’s SolarFlex Nova, a new generation UV ink, is provided with an advanced ink management system with a dispenser and color matching tools.
Ink companies have also been focusing a lot on upgrading services for printers using UV inks, particularly in the provision of technical support.
“Services in UV printing are very important, because they are a way of keeping the printer well informed,” said Alex Stevenson, chairman of Colorgen, a start-up in UV inks located in Haverhill, England, whose managers and technical staff are well-established experts in the process.
“We place a lot of value in the giving of information,” he added. “We have a small staff, but they have a lot of skills and knowledge in UV which can be extremely useful to printers. In recent years, printers have become much more aware of UV but they still have a lot to learn. We ourselves are always wanting to know more about the subject and to pass that knowledge on.”
Equipment manufacturers have been developing monitoring systems which enable printers to manage the UV process more tightly.
These include electronic tools which coordinate UV intensity levels with printing speeds and substrates while also detecting operating errors such as overheating and shutter defects.
There are many aspects of the UV process which can be measured, whereas each measurement can itself have many parameters, Reno Huber, product manager at Uviterno AG, a Swiss-based UV equipment manufacturer, told the Zeller+Gmelin seminar. At the same time, many different factors influence the quality of UV printing, he added.
Uviterno has introduced a process control system with a range of measuring points from which data is recorded, processed and archived to be used as a reference source for future printing jobs.
IST Metz, a German UV equipment maker, has developed similar data- gathering systems. It also provides components which help reduce energy use for the same amount of UV output.
The strategy behind Metz’s innovations is to seek improvements to the whole UV process rather than just to individual pieces of equipment. It employs computer tools, for example, to trace the UV rays so that the geometry of reflectors can be optimized.
Ideally, printers would like to have a device which would enable them to find out directly that an ink has been 100 percent cured.
“The ability to make sure that an ink is completely cured is a big issue in the narrow web industry at the moment,” said Mr. Ehrlitzer. “Printers want to know more than just the energy output of a UV lamp and other operating data at a particular moment.”
The equipment manufacturers point out that the data from their measuring systems provides a basis for determining a total cure.
“It would be extremely difficult to measure 100 percent cure levels because there are so many parameters to be taken into account,” said Gerhard Ohmach, a marketing executive at IST Metz. “Printers can instead use as a reference point the data they have collected from their existing measuring systems. They will then know the data needed for a complete cure.”
The strength of UV’s position in the Europe’s printing market is demonstrated by the limited rise in demand for electron beam (EB) curing technology. EB cures inks and coatings immediately with relatively small amounts of energy and, unlike UV, does not emit odors.
However, EB equipment is expensive, which is a major disadvantage during an economic crisis. EB also requires wet-on-wet printing, which continues to restrict its expansion outside the large format sheetfed sector.
“In Europe, EB has attracted a lot of interest,” said Peter Baird, marketing manager at Flint Group’s Print Media Europe in Manchester, England. “In spite of this interest, only a few printers are actually investing in EB-equipped presses. The emerging markets of Eastern Europe appear to be more open to the technology.”
LED curing could become a major rival to conventional UV curing technologies. Currently in Europe, the use of LED for curing is in its infancy. It could be many years before it becomes widely applied in European printing.