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FLEXO Magazine : December 2011
EDGE OF POSSIBILITIES Jacques Perreault is a connoisseur of dots. As the plant manager of Starflex Packaging, Inc., his discerning eye for four-color dot structure, dot gain, dot density and dot consistency has helped propel the Montreal-based wide-web FTA member printer to the forefront of North American premier- quality flexography. With full support of management, Perreault is al- ways eager to set expectations higher for his food, medical and pharmaceutical clients who need long runs of eye-popping flexible packaging, bags and lamination. Assisted by Printing Manager Alain Guimond, Perreault abides by the mantra, “Quality is not a goal. It’s a requirement. ” So, it’s no surprise that Starflex was an early adopter of high-quality, high-definition technology. The team realized that the advent of laser-engraved digital plates and software enabled finer line-screens and dot formation. The team also discovered that conventional 60° hexcell anilox rolls couldn’t al- ways deliver the printability benefits of wider color gamut, dot precision, less pinholing in process solids—and just as important—repeatability. Revolutionary plates without revolutionary ink-to- plate transfer was not good enough. So Perreault had a choice: stay with conventional hexcell anilox or take the next step to new “open slalom ink- channel” technology. Dubbed Genetic Transfer Technology (GTT), this “S” curve-shaped suc- cessor to hexcell anilox surfaces, was developed and patented by Netherlands-based Apex Group of Companies. It provided Perreault the prime benefits of “stability and less variation” within the demanding zone of 175 line-screen-and-up flexo on work run on Starflex’s 50-in. Carint gearless press. What’s more, with GTT, Perreault could reduce ink viscosity by at least four seconds to achieve target density. “ With GTT, the dot gain is smaller and the results are more stable,” noted Perreault. “ T hat’s why we are migrating our entire plant to GTT,” which includes geared and gearless presses. And though Starflex was one of the first North American printers to deploy GTT three years ago as a “beta tester,” Per- reault was wowed again by a recent trial of GTT rolls coupled with DuPont Cyrel Digiflow DFQ digitally-engraved plates powered by Esko software: “In the 250-line screen tests, these were the nicest results we’ve seen,” he recently reported. Even after tens of thou- sands of meters, densities didn’t drop off as they did with 60° anilox. Mottling and pinholing were reduced. And, he enjoyed “obviously less cleaning of [GTT rolls] and printing plates.” Plus, “GTT eliminated the fact that you constantly had to ad- just pressure and viscosity around banding. The solids in our process work are fantastic.” Perreault recalled his optimism from just four years ago at the ability to print 175-line screen process work using conventional hexcell anilox rolls. “ We used 1200-1400 LPI [Apex] UltraCell-Plus hexcell anilox rolls, which were among the highest quality anilox available.” High print quality was achievable in tests and short runs at these extreme toler- ances. But, he admitted to being disappointed because “ink transfer wasn’t stable or predictable enough” over long runs. Perreault, like so many flexographers, had “hit the wall” of hexcell anilox technology ’s Achilles’ heel: repeatability. Willing to experiment with new technology, Perreault was intriqued when Apex introduced GTT as an upgrade. Work- ing with Apex Director of Sales Aaron Lessing, he began to improve printability while maintaining consistency. In the wide-web arena, GTT is branded UniFlexGTT and is available in five sizes, which correspond to the range of conventional hexcell line screens and volumes. The sizes include: • “XL” for heavy solids • “L” for solids and screens • “M ” for mid-range • “S ” for mostly screens • “ XS” for high-definition and dedicated process printing In a head-to-head trial at StarFlex of GTT vs. UltraCell-Plus conventional anilox, Lessing recommended testing magenta as the control color, as it’s one of the hardest density targets to hit. They compared a high-LPI UltraCell-Plus anilox against the UniFlexGTT XS. The commonalities were DuPont Cyrel www.flexography.org december 2011 FLEXO 31 5004003002001000435.68CONV.GTTCONV.GTTCONV.INKUSAGEKILOGRAMSSOLVENTUSAGE204.50CONV.186.50GTT314.10GTT UK Wide Web Trial Total Ink/Solvent Consumption: GTT vs. Conventional Anilox