Jason Hammer doesn’t play favorites when it comes to printing processes or label market segments.
Housing flexography, offset and digital under one roof, his aim is to produce the highest-quality labels for all Hammer Packaging customers. With pressure-sensitive, cut and stack, roll fed, in-mold and foam labels, Hammer has the label market covered. Throw in flexible packaging, pouches, shrink sleeve and specialty packs and it’s hard to classify Hammer in any single packaging category.
“Our high-end offset background has instilled a bias for quality throughout our organization,” reflects Hammer. “When we added flexography, we did so with the goal of equaling offset quality. We match printing process to customer needs. We don’t want quality to be one of the criteria.” Installing the initial Esko XPS Crystal 4835 plate exposure unit in North America was one of the key pieces of that plan.
The 35-in. x 48-in. plate exposure unit was a perfect size for Hammer’s existing plate imager. “The side-by-side plate imager/exposure bundle was attractive to us, but we already owned a plate imager that was in near perfect working condition,” reflects Paul Rainville, director of prepress at the Rochester, NY converter. “So, we purchased the LED plate exposure unit, standalone, to work with our existing plate imaging unit.”
In piecing together flexographic plate making technologies, there were two issues of primary importance to Hammer Packaging. One, for sustainability reasons, it wanted to avoid solvent plate processing. Two, it wanted high-quality color reproduction on paper and film. Both had to equal the quality it was already getting in offset and digital.
“Prior to making the move into specialty screening and LED exposure, thermal processed plates took extra efforts for us to meet our high expectations for dot quality,” reveals Rainville. “Now, we are getting consistent dot quality that we need across both paper and film substrates.”
Reflecting on the current surge of LED plate exposure units going into narrow web flexographic markets, Esko Director of Business Development Rory Marsoun shares some insights. One reason the technology was developed in large format (50-in. x 80-in.) before small format (35-in. x 48-in.) was related to basic engineering.
“Most industrial equipment is brought to market in smaller sizes, then scaled up to larger sizes, if demand warrants. That’s usually done for marketing reasons,” reflects Marsoun. “From an engineering perspective, you get better equipment if you design for the large size and scale down to smaller sizes. All the uniformity, deflection and structural tolerances for the large size work for the small size, but the reverse is not true—You can’t just take the numbers from the small device, scale them upward and expect the same precision engineering.”
Esko’s XPS Crystal LED flexographic plate exposure technology was announced at drupa 2016 and brought to market in the 50-in. x 80-in. format that summer. “The primary focus was wide web flexible packaging and the timing and technology were a perfect fit,” recalls Marsoun.
Two years later, the 35-in. x 48-in. unit was introduced with a focus on labels and other narrow web applications. “It was about this time that customers were telling us that LED plate exposure benefits were not only about consistency, but also about quality,” notes Marsoun.
The difference between XPS Crystal plate exposure and “conventional” plate exposure is the light source. Conventional flexographic plate exposure units use high UV output fluorescent bank lights; XPS Crystal plate exposure devices use light emitting diodes (LEDs) [see sidebar]. Fluorescent bank lights have a large amount of variation, require warm-up time, generate heat—which adds to variation—and are classified as a hazardous waste for disposal purposes. LEDs have extremely high consistency, no warm-up time, generate very little heat and can be disposed of as normal waste. Additionally, LEDs last at least 10 times longer than fluorescent bank lights and have numerous sustainability benefits.
Esko’s original LED plate exposure system to be installed in the US was a 50-in. x 80-in. system at SGS in Minneapolis, MN in the fall of 2016. This system included a plate imager combined with an LED plate exposure unit.
The large format fit perfectly with SGS’ objective of offering a higher quality, more consistent plate to wide web flexible packaging converters. SGS Plateroom Manager Chuck Schoen reveals: “We’ve been running non-stop since installation more than three years ago. I can tell you that it produces the most consistent plates that I have seen in 32 years of working and managing flexographic platerooms.”
Scott Thompson, VP of technical sales and innovation, adds, “LED plate exposure technology has demonstrated the ability to produce flexographic print quality we couldn’t have imagined just a few short years ago.” SGS liked the LED plate exposure technology so much that it added a second unit in its Mississauga, Ontario facility. “The greatest benefit of all may be the ability to make the exact same plate in two locations,” states Ken Derstroff, director of operations for SGS Mississauga. “For a company like SGS, to satisfy brands and converters around the world, inter-device consistency is critical.”
Automation a Priority
In 2018, Simon Dumais, prepress manager of Imprimerie Ste-Julie in Sainte-Julie Quebec, Canada, began a major search to improve flexographic print quality. “We serve traditional markets such as labels, shrink sleeve and pouches, as well as high-quality niche markets, such as liquors, linerless and cosmetics,” he reveals. “Continuous quality improvement is an integral part of my job.” Having recently replaced a film lamination flexographic plate system with a LAMS system, Dumais had already created, used and analyzed a variety of test charts to show specific aspects of flexographic print quality.
“Testing the LED plate technology was simple,” he recalls. “I sent the test charts to Esko, it made plates and we printed the plates on our press. You could see the difference and measure the difference.” Bringing in a new CDI posed an interesting choice for Imprimerie Ste-Julie. “We could go with the tried-and-true CDI Spark or the new CDI Crystal,” says Dumais. “We went with the CDI Crystal because it has the growth path toward automation.
“Automation may be an even higher priority than print quality,” he continues. “It’s at the heart of every decision we make.” The plate making architecture currently installed at Ste-Julie uses the automatic plate loading to load and unload plates on the CDI, and uses a human to slide the plate from the CDI table to the adjoining XPS table. “We’re happy with the level of automation we have today,” says Dumais. “I like the idea that we can add the automated plate mover when we desire.”
Closely related to automation is productivity. Combining the throughput of the plate imager and LED plate exposure units with thermal plate processing, a complete set of plates can be produced and press ready in less than 45 minutes.
“We did time studies of our former masked-based system, compared to our new system and found that throughput is more than 50 percent higher,” reveals Dumais. “We not only get a plate out faster with less human touch points, we also produce more plates per shift.” As a supplier of both flexographic and digital technologies, Imprimerie Ste-Julie’s policy is to remain impartial. But when asked if flexographic print quality was as good as digital print quality, Dumais had a very simple response: “It’s better!”
Print Quality Hub
“Business growth was the factor that drove us to upgrade our plateroom,” remarks Thomas Dahbura, Hub Labels president. “Our current Hagerstown, MD location has grown to 110,000 sq. ft. with more than 20 presses.” More presses means a demand for more plates. “We began the investigation to update our plateroom in 2019,” he recalls. “We had three parameters we set out to optimize: sustainability, productivity and quality.”
Sustainability was the simplest. For plate exposure, it meant LED over bank. For plate processing, it meant thermal processing over solvent. “Bank lights are classified as a hazardous waste. The process of replacing and disposing of the fluorescent tubes is non-value adding activity with both safety and environmental implications,” says Dahbura. “LED lights last at least 10 times longer, are replaced on a very infrequent basis, and are not classified as a hazardous waste.”
Plate processing may yield an even larger environmental benefit. Compared to solvent plate processing, DuPont’s FAST thermal plate processing system boasts 63 percent less non-renewable energy consumption, 53 percent less greenhouse gas emissions, and 99.7 percent less Volatile Organic Compound (VOC) emissions. “In terms of sustainability, there’s just no comparison between an LED/thermal workflow and a bank light/solvent workflow.”