Digital Magazine

Delivering Digital: CTP Carries Flexo Printing to Competitive Quality

I want a T1, DSL, digital cable line. That doesn't make any sense, right? For some of us, indeed, it doesn't make any sense. For others of us, well, we're not quite sure if it makes sense or not. But we do know, somehow, they're related.

More and more, it's the same for printing via a traditional methodology (flexo, in this case) and the digital buzz we encounter these days. Flexography (and probably all printing methods some day) and digital printing are invariably linked; significant advances in CTP (computer-to-plate) have secured this coupling.

What's more, digital stations retrofitted to flexo presses have entered the marketplace and made short-run, variable-information printing not only a reality but increasingly commonplace. (See Product Focus, July 2001, p. 88: “Digital Printing at Your Service: Keeping Customers Happy.”)

But it's digital platemaking technology that's soldering the flexo-digital link. “Digital-plate technology, as a workflow, is an advantage,” says Colleen Larkin, industry manager, MacDermid Graphic Arts, Atlanta, GA.

“Digital workflows for platemaking [will remain a] really hot topic,” agrees Ken Lowden, marketing/industry relations manager, DuPont Imaging Technologies, Wilmington, DE. “One advantage of digitally created plates: shorter time to market. Everybody wants cycle-time reduction. Also, users reduce consumable costs while producing the best image quality possible.”

CTP, eliminating the analog film-imaging step altogether, is helping make all these possible, Lowden asserts.

Additional advances in flexo printing plates aren't limited to the digital domain; technological strides in plate structure are raising flexography to new quality heights, too, report Lowden and Larkin.

“A big trend recently is thinner plates,” says Larkin. “The advantages of that: With less photopolymer*, you're going to image better. Also, because there's less pressure required for ink transfer, thinner plates provide better durability.”

Jim Accuosti, converting division manager, Bell-Mark, Pine Brook, NJ, says another recent development is the “capped” plate, which is a plate with a thin top layer on its surface. “The surface slows exposure, thereby creating a matte texture, which has an excellent affinity to ink, and, thus, a more uniform ink transfer,” he explains.

Both Accuosti and Larkin say plates compatible with ultraviolet inks are getting better, too; both companies offer UV-compatible products.

Also, Lowden reports, thermal printing plates now are available from DuPont. “The significance: First, it takes no water or solvent to process. You eliminate all that chemical use and storage. Secondly, there's a productivity gain; because you don't have to dry it, it takes platemaking time from four hours to about one.”

Imaging onto performance-enhancing sleeves is something from which flexo printers can benefit as well, says Larkin. “Digitally imaging plates directly onto a compressible sleeve provides a web flexo printer the best platform he or she could want — durable plate cylinder activity with an excellently imaged plate.”

Digital imaging and improved composition are taking flexo plates, the “brain” of the methodology, as Larkin calls it, to new quality levels. This “brain” is responsible (along with other OEM innovations) for the flexo industry's increasing ability to compete with gravure and offset.

And platemaking suppliers certainly aren't the only ones touting flexo's improved quality status: HDF (High Definition Flexo) is a supplier consortium (with Harper, Comco, Swed/Cut, Smurfit-Stone, UV Technology Inc., and others) that's recently released a white paper on the growth drivers of the HDF market.

Now, if I could only get my brain straight as to what kind of digital-data conduit makes sense for me: T1, not possible; DSL, soon; digital cable, definitely a couch-potato craving for future consideration. For now, I should be happy I know the difference.

But for the flexo industry, from platemaking suppliers to flexographic printers to the many OEMs in between, it's just the opposite. They're quite happy about the decreasingly naked-eye difference between flexographic print quality and that of other methodologies.

*Photopolymer plate composition was pioneered to replace rubber plates, says DuPont's Ken Lowden. But, he notes, rubber plates are not extinct. “Typically, rubber plates are utilized for products that don't need high-impact graphics. Or they're doing some type of engraved rubber. There's still rubber out there; the printing markets in Europe and the Americas are well advanced, but it's not like all the world is converted to photopolymer.”

Restrictions of time and space limit the number of companies, products, and trends that we can discuss in these reports. For additional information, see PFFC's features and departments each month and consult the June Buyers Guide.

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