Where Materials and Minds Meet

Coating and laminating in-line takes a few imaginative turns.

By Susan Friedman

For package printers, the basic equation for in-line coating and laminating installations—flexographic printing plus flexible packaging—remains the same. At the same time, though, active "additions" for coating and laminating are on tap: more applications, more accuracy and ease-of-use, and, likely, more creative retrofits.

In 1999, in-register cold-seal adhesives received a good deal of in-line application buzz, but now other uses are angling for attention and elbow room. Hans Deamer, senior vice president at Windmoeller & Hoelscher, confirms in-line coating/laminating's continuing importance, and cites additional layers of growth within the flexible packaging arena.

Deamer believes cold seal's growth has stalled in the past year, and that the application is facing overcapacity. More measurable momentum can be found, he says, behind in-line (and off-line) solvent-free lamination, which has grown not only due to its environmental benefits, but its ability to eliminate solvent costs and dryer energy costs. Early problems with ink and adhesive compatibility have been overcome, and the latest generation of solvent-free adhesives has improved performance.

Printco Industries' Account Executive Matt Burie predicts flexible packaging will continue to lead the in-line pack simply due to the volume involved, but notes new products have also touched off a surge of in-line activity in both business forms and tissue/towels.

As far as package printing is concerned, coating and laminating activity continues to be strong both on and off the press line. Deamer expects shorter and shorter run lengths, and their requisite changes in web widths and adhesives, to continue to render roll-to-roll, off-line equipment an attractive option.

Mid-web, however, with its claims of short-run cost-effectiveness, may be a major ticket to market for in-line. Tom Jacques, marketing strategist for Paper Converting Machine Co., reports, "More mid-web press owners are looking to add in-line stations for flexible packaging and labels to increase the value of that packaging to the final customer." Jacques ticks off a list of mid-web end product applications including potato chip bags, peanut bags, soda bottle wraps, and trading card wraps; in-line pattern coater products such as candy bar wrappers (with cold-seal adhesive), fresh-cut produce salad bags (with anti-fog coatings); and in-line flexo station products such as backside game rules, bottle wraps, and ice cream wraps.

Burie notes many improvements in in-line operations currently stem from enclosed doctor blade chambers, more accurate gearless drives, and more precise anilox rolls. Other operational advancements soon to be out and about include Dri-Tec's new RegiTrend™ software, which monitors variance in repeat length after lamination, and then spreads out that variance to eliminate larger "catch-up" corrections to registration down the line. Benefits of direct-drive, infinitely variable repeat presses—centered mainly in ease-of-use and universality—also carry over into attached coating and laminating units, Deamer adds.

Retrofits: creative additions

An in-line retrofit can help converters avoid "one-size-fits-all" installations, Burie maintains. In fact, creativity is an almost mandatory starting point.

Converters who must expend extra effort to solve a tricky application may turn to used equipment to balance the budget side of the situation. "A new line that could run $850,000 might only cost $250,000 if bought used, as is, or as little as $450,000 if bought used and reconditioned," observes Matt Tielkemeier, Dri-Tec VP/GM. "Once the converter gets to capacity, he'll order a new machine. Or, new drives and computer controls can be added to old equipment to bring it close to new."

A creative transformation along these old-to-new lines recently took place at The Outlook Group Corp., a printing firm offering both flexo and letterpress services for packaging and labels, as well as sheetfed offset commercial printing.

Outlook's initial in-line coating/laminating configuration, comprised of used equipment and components and placed behind a 45˝, 6-color flexo press, didn't take efficiencies quite as far as the company wanted to go. The rubber rolls on its older coating station, for instance, required 45-minute changeovers.

But the biggest issue, recalls Operations Manager Jim White, was poor tension control—a condition that couldn't continue in light of the high level of thin film work that had to go through the line, such as coffee bags with a layer of 44 gauge metallized polyester laminated to a layer of 1.5 mil polyethylene, and pork sausage wrap with a layer of 1.35 mil polyethylene laminated to a layer of 1.35 mil Saranex.

Working with Dri-Tec on a second in-line configuration, Outlook solved its tension troubles by taking two measures: incorporating servo electronics for accurate tension control throughout the run, and reversing the coater and laminating nip sections to put the laminating nip closer to the secondary unwind.

On the original line, the secondary (more extensible) web was coated and dried, and met the primary web at the combining nip in the center of the two machines. With the new design, the primary web, which is generally thicker gauge and more stable, is printed, sent through a turning bar and coated, and then joined with the secondary web at the combining nip, which is now positioned back from the middle of the machine, closer to the secondary web. White says coating the more stable substrate and shortening the secondary web path has allowed Outlook to control tensions, reduce web curl, and increase speeds by 50 percent.

The upgraded, reconditioned line, which incorporates a new gravure coating station and a new secondary unwind, has not only helped Outlook secure a large amount of newly acquired coffee packaging business, but also serves as a ready show-piece.

"We built this line to be very cosmetic, and are now comfortable bringing customers through," White comments. "With this upgrade of machinery, our customers feel confident with our ability to get them a quality product in a shorter time period."