It's a demanding business. There's no room for 'good enough' or 'commercially-acceptable,'" says print cell manager Bruce Warkentien. "The labels we print have to be perfect because they're crucial to the way the finished product looks and sells."

Warkentien knows what he's talking about. Labels produced by his employer, St. Paul, MN-based Smyth Companies, are mostly retail-oriented, appearing principally in mass-marketed products where label appearance is a vital part of packaging, marketing and merchandising.

Smyth is an integrated producer of glue-applied, sheetfed-offset and pressure-sensitive, flexographic labels. They also handle package-centered promotional vehicles, point-of-purchase materials and labeling systems. One of the country's largest consumer-products labelmakers, Smyth has more than 550 employees at four locations in Minneapolis, St. Paul, Austin, MN, and Bedford, VA.

A typical plant, such as the headquarters facility in St. Paul, runs four 44-in. Komori Lithrone 44 sheetfed-offset presses. Two presses are 6-color, one is 8-color plus coater and a fourth is a 10-unit model (8-color plus coater, 1/c backside).

Starting in the late 1990s, the four Smyth plants began manufacturing initiatives aimed at improving product quality while lowering electric-utility costs. A key component of the initiatives has been the installation of high-pressure humidification systems from ML System A/S (Ry, Denmark) and its North American distributor, Husson, Inc. (Sturtevant, WI).

Like many printers and converters in Northern-tier states, Smyth's label printing plants were bothered by quality and throughput problems caused by overly dry air. According to Warkentien, problems were mostly seasonal. They occur mainly when icy-cold Minnesota winter air was heated to a normal 70 F in the plant, dropping relative humidity (RH) to 10 percent or less. Optimum RH levels for printing and finishing labels is 45–55 percent at 70 F.

"We always had more waste and more rejects in winter when the bottom dropped out of our humidity," Warkentien says. "Static electricity caused problems throughout the entire process—from our sheeting area, through the press room and into finishing and diecutting. And dried-out paper and other stock caused its own printing and finishing problems."

For instance, as static-charged 32 × 44-in. sheets came off presses, they clung tightly to one another, without being parallel—like stalks of hay in a jumbled haystack. Sheet-separation problems led to this "haystacking" of sheets in the jogger prior to guillotine cutting, making it difficult to get a uniform edge prior to cutting.

Smyth cuts sheets into individual labels before diecutting, rather than diecutting whole sheets. The individual labels are stacked 30 deep, then die-cut in batches of 1,000 labels. "Haystacking" made it nearly impossible to get a reliable edge, so cuts weren't precise, leading to waste.

Dry air also caused dimensional instability of unprinted stock, including paper shrinkage, bowed sheets and wrinkling. "All of our stock comes wrapped, but very soon after you unwrap paper or other substrates they start losing moisture," Warkentien says. "And once shrinkage occurs, it's usually impossible to fix. Stock that's shrunk, bowed or wrinkled is largely unprintable or doesn't register for finishing."

Some Smyth operations had tried to combat static electricity and dry-paper problems using electric-steam humidification, ultrasonic systems and other technologies. But according to recently retired Smyth operations chief Ken Rush, none had the capacity or the consistent performance throughout the plant to solve the problems. Moreover, Rush and the Smyth project team felt energy costs and maintenance requirements of the company's electric-steam systems were excessively expensive.

Rush and other Smyth executives sought solutions, that would reduce static electricity and dimensional stability problems through improving the consistency of humidity levels in the plants, while also reducing maintenance and energy costs.

After reviewing alternatives, Smyth installed high-pressure humidification from ML System in its Austin facility. The system met the plant's capacity needs, distributed its fine, cool mist uniformly with an integral fan and had energy costs only about 1/100th of that of electric-steam system, the converter says.

Rebates from local electric-power companies to encourage more efficient energy use were an extra incentive to replacing the electric-steam system with high-pressure humidification. A financial analysis showed that reduced electricity costs alone would lead to investment payback in less than two years.

Smyth's humidification systems use standard ML pumps and controllers in a centralized control area. Remote sensors in several zones in each plant measure RH levels. If RH in any zone drops below the desired 45 percent, the ML automatically triggers humidifiers in the area. Along with the ML humidification system, Smyth also runs static eliminators on its presses.

"Our humidification system provides a consistent level of humidity, which reduces static, but can't eliminate all of it," Warkentien says. "Some of the sheets we run have static electricity in them inherently."

The ML installation in Austin quickly met its goals for consistent RH, waste reduction and lower maintenance and energy costs. Installations in St. Paul, Minneapolis and most recently in Bedford followed, all meeting their performance goals and achieving rapid payback.

"We've had a very positive experience with ML high-pressure systems," Warkentien says. "In every plant, we've achieved our goals. The savings have been significant enough that our payback has consistently been two years or less."