In for the Long Haul

Today's near-necessity of value-added coatings persuades more converters to embark on the in-line path.

By Jessica Millward, Associate Editor

For those in the know, coating and laminating are quickly becoming part of the basics of package printing. Today's sophisticated packaging has given birth to a dizzying array of coating/laminating combinations and capabilities, and the in-line process continues to reap the benefits. Applications are increasing across the print process board, in flexo, in offset, even in gravure.

Of course, in-line is still best-suited for longer-run work. Though Matt Tielkemeier, Dri-Tec's VP/GM, notes in-line's potential for short runs will grow with the development of robotic presses, he believes, "Robotic coating and laminating equipment won't be available for several years." For shorter runs, and, as Tielkemeier relates, for truly "exotic" applications, off-line coating is usually the system of choice.

In the offset arena, Heidelberg has supplied in-line coating units on sheetfed offset presses for almost 20 years. Detlef Janke, marketing director for the Speedmaster 102, reports the majority of machines the company sells are now equipped with at least one coating unit. "This has become the standard for all parts of the industry," he asserts. "While it was, at the beginning, only aqueous coating to protect the printed sheet and allow faster finishing, it is now more value-added coatings that are gaining the industry's interest."

In-line's proven efficiency guarantees it its place in the coating/laminating hierarchy. The big issue facing potential "in-liners" now is the exact equipment set-up their packaging requires. As Janke, describes, "Printers don't want to coat only after printing, [they also want to coat] even before, or before and after."

Branching out

While it's sometimes difficult to keep up with the breadth of uses their equipment is engaged in, coating/laminating suppliers definitely discern several applications that rack up the most requests.

For Kroenert's National Sales and Marketing Manager Kent Shouse, it's all about energy-efficient, UV-curable coatings and adhesives. He cites UV silicone release coatings; UV 100 percent solids liquid polymer acrylic PSAs; and a new class of UV low-melt-index, hot melt PSAs for tags, tapes, and labels as prime examples of the move away from thermally dried and cured coatings. Shouse also predicts a big future for in-line UV silicones, paired with UV PSAs or hot melt adhesives, for linerless tapes and labels.

In-line lamination is still a hot topic, as flexo printers continue to develop end-use-specific converting methods. Michael Ferrante, VP/sales at Preferred Systems, Inc. (PSI), sees a number of new line and retrofit installations involving the ability to print up to ten colors, in-line laminate, and apply an in-line cold seal in register for bottle labels and candy wrappers.

Relatively traditional dry bond applications also have a new emphasis, Ferrante explains. Thinner, lower-gauge films, and specialty substrates, such as the anti-fog film used in pre-cut salad packaging, will keep steady pace with more high-profile coating practices. Solventless lamination is not to be forgotten about, either, he claims, as it infiltrates certain markets and hedges more toward LDPE/LDPE applications.

Heidelberg has ventured into unique flexo-offset combinations through coating and laminating. Janke details how the company has printed offset inks and applied metallics by utilizing flexo plates on a coating unit. Another popular configuration, he says, is "printing in-line with conventional inks, applying a waterbased primer to seal the fresh print, and applying a UV gloss coating on top."

In auto-motion

As is true with most sectors of printing equipment, coater and laminator manufacturers aren't hesitant to make the move toward more integrated, automated machine control. Dri-Tec's Tielkemeier believes the use of more automation will inevitably result in better quality printing. "With automation features," he insists, "the operator pays more attention to running a good product, rather than to babying the machine." Automation also allows faster operator training, he states.

Dri-Tec produced RegiTrend™ software for its coating lines to take advantage of those benefits. Tielkemeier comments, "Often times, especially with something like a polyethylene web, the register changes." Based on an artificial intelligence model, RegiTrend measures variance after the lamination process, and corrects that variation through the line in tiny increments, rather than in one gross adjustment.

PSI, too, has gone the way of "e-control," offering centralized control systems, complete with online real-time monitoring and reporting functions. The Toolless Roll Removal System (TRS) for gravure roll exchange and sleeved impression rolls also cuts makeready time.