UV in the spotlight

A new type of curing system that, it was claimed, “could change the face of UV in the printing industry” was launched at Labelexpo Americas 2012 by the working partnership of Mark Andy, Flint Group and Phoseon Technology.

ProLED is a “complete and integrated” curing system based on Phoseon’s FirePower UV-LED technology. Using solid-state semiconductors, the principle difference of the new technology over conventional mercury-based lamps is that it uses medium wavelength UV, which avoids ozone and heat generation.

The partners claim that this offers advanced capabilities, with economy of operation, and ‘green credentials’ that “leave existing systems far behind”. Operating at 16W/cm², it is predicted to show an ROI of less than 12 months, with a far higher level of press uptime than is currently possible.

The drawback is that the system will not cure conventional UV inks and lacquers, so a range of EkoCure inks (F for flexo, S for screen) is being offered, with development underway for coatings, metallics, shrink whites, and laminating adhesives.

Pro-LED is designed for use on flexible packaging, folding cartons, labels and shrink sleeves, and is claimed to consume 50% less power than existing systems. With maintenance also reduced (by up to 75%) due to the absence of blowers and ducting, and no moving parts such as mirrors and shutters, the whole system has a footprint half the size of existing UV set-ups.

New users

Greg Palm of Mark Andy says: “This technology will bring UV to new users because of its low cost and simplicity. For existing users, it offers a deeper and faster cure, but it also brings in those who are running water-based inks.”

He adds: “In the five-year trial we ran, we didn’t have single LED failure”.

In fact, the Beta site in the US is a water-based press, which substantiates what Palm says about attracting new business by having UV/WB combi capability. Designed initially for OEM fitment, the new system also has great sales potential in the retrofit market, where its size makes it an easy shoe-in on existing presses, UV or otherwise.

Also at Labelexpo Americas, GEW launched the next generation of e-Brick power supplies incorporating new design elements to increase energy efficiency.

Users can now select the power level required for the job depending on the properties of the ink, coating or adhesive at the appropriate press speed. Rather than being set by the manufacturer, users can now select whatever power they need to print a specific job, while being assured of the highest level of energy efficiency.

“The tendency has been to use full power to combat the risk of under-cure,” says Brian Wenger, president of GEW’s USA operation.

“Our aim is to reduce energy costs and prevent spoiled print jobs by using the minimum power required to cure, with extra in reserve for the more difficult jobs.

“We have achieved this through further development of the e-Brick electronic power supplies, UV lamps, reflectors and software, and by developing a range of scientific tools to monitor UV output.”

In addition, GEW now offers remote diagnostics that enable minor issues that affect UV curing to be corrected via the internet, eliminating downtime and service calls. Also, average system standby can be reduced to well below 15% through the use of the Greentimer facility.

Dr Hönle has developed a broad band sensor for the measuring of LED wavelengths, to assure production process security and for reliable and repeatable test results in the R&D laboratory.

LED irradiation units do not produce a broad UV spectrum, but emit narrow bandwidths at specific wavelengths. Therefore, any UV measurement of these bandwidths with conventional sensors is inaccurate. To enable the measurement of LED UV units, the broad band sensor developed by Dr Hönle can measure across the bandwidth of all LED wavelengths – from 365 to 405nm – with only one sensor. The new sensor is attached to a standard UV meter which displays the measured value in W/cm² or mW/cm² with a maximum intensity of 20W/cm².

Integration Technology Ltd (ITL) reports growing interest in applications for its LED Zero series products in many applications such as product packaging, printed electronics, and photovoltaics as well as wide format digital printing, where the company already has significant market share. Seven new air cooled UV LED’s plus a further three new water cooled versions are now available to complement the existing Pincure and Solidcure products.

ITL and IST recently co-hosted a conference on UV LED curing in the US. Key outcomes suggested that UV LEDs were not merely replacing LEDs but opening new market opportunities for a technology that is “going from strength to strength”. The event in Chicago followed a seminar in Paris earlier this year. Another event on the topic will be held in Europe next spring.