Curing and low-migration – what’s it all about?

IN the ongoing drive towards higher performance and more environmentally-responsible production, curing developments come thick and fast, as OEMs forge new partnerships with component suppliers and introduce ever-more effective technologies.

Among these, EB, UV and UV LED are curing acronyms currently in the news. And, as an increasing number of printers opt for UV LED technology, and the process gains traction, the cost of UV LED inks is becoming more competitive. So, with its eco-efficiency, cost-effectiveness and productivity advantages, this is among technologies driving printing industry development. However, an increasingly-important ink-related topic is that of low-migration, particularly in food packaging applications. Here we provide details of some recent product launches . . .

Low-migration UV LED ink from Flint

Flint Group has announced the global launch of EkoCure ANCORA, UV LED curable low-migration inks suitable for food-compliant labels and packaging applications.

This counts among the latest innovations for the narrow-web sector, combining revolutionary UV LED curing along with low-migration food-compliant chemistry. Together, the technologies enable food-safe printing with high reliability and productivity thanks to stable curing at high press speeds and optimised UV LED ink chemistry.

As highlighted by Guillaume Clement, global VP for Flint Group Narrow Web, this development fits in with the company’s commitment to support food-compliant labels and packaging.

‘It is with great excitement that we commercialise this new product line,’ he says. ‘It expands our ANCORA low-migration portfolio and enables converters to grow their businesses with short-run flexible food packaging.’

And Kelly Kolliopoulos, global marketing director, adds: ‘The innovative journey in developing UV LED curing products, started four years ago, is culminating in a milestone development – low-migration UV LED curable inks.’

Flint believes strongly in low-migration UV LED technology. The combination offers the economic benefits of UV LED curing, including improved press uptime and productivity and reduced energy consumption; along with assurance that packaging is safe for food products.

The company has finalised investments in GMP production capabilities in Sweden and the US, and is now commercialising these first-ever low-migration UV LED flexo inks globally. Flint has also completed an intense period of beta tests with selected converters, lamp and press partners who collaborated on this ground-breaking development.

Explains Tom Hammer, Flint Group’s North American product line director: ‘We were pleased to partner with two press suppliers at Labelexpo Americas in Chicago as both Bobst and Mark Andy were running EkoCure ANCORA live at the show. Bobst showed the REVO process utilising seven-colour process; and Mark Andy demonstrated a LED flexible packaging press and extended colour gamut printing.’

According to Mark Andy’s Greg Palm, LED printing will change the industry forever. ‘It is a paradigm shift,’ he says. ‘With LED curing converters no longer have to accept the unnecessary downtime associated with mercury lamp failures, inefficiencies and hazards. We ran a narrow-web flexible packaging job at 300m/ min with excellent cure performance using EkoCure ANCORA low-migration LED inks and Mark Andy ProLED at 20W/cm2 . The combination of LED lowmigration inks and highly efficient printing presses will become an unbeatable combination to address increasing demand for shorter and shorter run lengths in the flexible packaging market.’

The ink offers low migration properties achieved at very high print speeds (in excess of 150m/min) and is suitable for the most stringent food label and packaging applications meeting migration levels below 10 ppb, 50 ppb or SML and compliant with Nestlé Guidance Note, Swiss Ordinance and FDA regulations.

It also offers very good colour strength and adhesion to a wide range of synthetic substrates.

EkoCure ANCORA is available in the full range of Pantone basic colours, CMYK plus orange, green and violet for expanded gamut printing, and opaque white, as well as a range of coatings, adhesives and metallics.

EB curing option for Digicon 3000

Through close co-operation, ebeam Technologies and Edale have achieved the integration of ebeam’s electron beam (EB or ebeam) curing technology into the Digicon 3000, a product co-developed between Edale and AB Graphic International. So far, three Digicon sales with the ebeam configuration have been made to converters in the US and EMEA with two customers including ebeam lamination as part of the configuration.

The Digicon 3000 is a mid-web finishing solution for digitally-printed flexible packaging and labels. It’s highly configurable, offering numerous options including finishing for labels, shrink sleeves and POS/ POP as well as inline coating and lamination of flexible packaging and labels. It’s also compatible with the HP Indigo 20000 digital press.

EB curing has numerous benefits when integrated into post-press finishing, especially in relation to the wider materials printed on an HP Indigo 20000. These benefits include improved print integrity and visual presentation as well as substantially increased durability and abrasion resistance. It is also good for the environment, eliminating the need for solvents, produces virtually no VOCs and requires very little energy. Another important benefit is speed. EB curing is instant and because output from an Indigo is often surface print, it’s possible to surface coat for protection, and immediately send for slitting and pouch or bag forming.

For food packaging converters particularly, EB inks and varnishes contain no photoinitiators so the risk of migration is negated, resulting in food-safe packaging. ‘Electron beam curing is a fantastic option for Digicon 3000 customers because it resolves many key challenges such as fast turnaround times and environmental factors,’ says James Boughton, Edale’s MD.

‘We are seeing a lot of interest from finishers and converters, especially in the food sector because of the safety aspect and with three and counting, already the word is spreading fast.’

Adds Karl Swanson, VP global sales, ebeam Technologies: ‘We’re delighted to be working with Edale on the integration of ebeam curing into the Digicon 3000. The benefits in terms of faster line speeds and food safety are clear and give Digicon 3000 users a real competitive edge.’

Successful test and first sale of Uteco UV LED flexo press

A Uteco Onyx 810 CI flexo press equipped with UV LED curing technology from Air Motion Systems (AMS) has passed its print tests and is now ready to be shipped to Italy’s La Gerunda Merletti. This is said to be the world’s first UV LED-enabled, ultra-fast, low-migration VLF flexo press.

The Onyx 810 has eight printing stations, 1 250mm maximum web width and 1 100mm maximum print repeat cycle. Seven AMS UV LED curing lamps are fitted at the printing stations around the CI drum with the eighth situated at the exit of the web on the top deck.

The press is also supplied with housing for a ninth AMS unit, adjacent to the eighth, if La Gerunda Merletti should decide to upgrade the press to the 500m/min option with the next AMS UV LED lamp development, the XP Ultra.

During the tests, the team from La Gerunda Merletti was joined by specialists from AMS to see the press deliver ‘excellent performance’ at running speeds up to 400m/min. Colour vibrancy and tight registration were reported as being maintained at all speeds, even during changes in speed, and the printed substrate was ASTM tape-test dry on the roll in the delivery. Further, because there is no heat emission during UV LED curing, the printed roll was ready for immediate downstream processing.

AMS lamps use blue light LED, switching on and off instantly, eliminating the need for a stand-by mode and using much less electricity, offering typical savings of 60% over conventional UV.

According to Pino de Gradi, La Gerunda Merletti MD, these operational benefits offer him a clear manufacturing advantage over his four existing UV and EB presses, although the technical and environmental characteristics of the new Uteco system are of equal importance, as his company targets new market sectors.

Siegwerk’s LED UV inks for food, pharma packs

Seven years ago Siegwerk’s ink specialists were the first to demonstrate the use of inks matched to the specific radiation spectrum of LED UV light – that was on a Gallus EM 280 at Labelexpo 2009 in Brussels. Expectations of UV printing inks are high, particularly in the food and pharmaceutical sectors – users want the highest level of product safety and minimal migration risk coupled with optimal efficiency and short production time.

And now, Siegwerk has expanded its portfolio of lowmigration UV printing inks for food and pharmaceutical packaging with the Sicura Nutriflex LEDTec series. Siegwerk regards LED UV curing as one of the growth drivers in the market. ‘We anticipate a volumerelated switch from conventional UV to low-migration UV inks,’ comments Rolf Montag, product manager for Siegwerk’s Narrow Web BU.