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Something in the air

Oct 1, 2005 12:00 AM

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Imagine!, an $87 million printer located near Minneapolis, has worked hard to keep up to date and cost-effectively produce high-quality products—it was among the first U.S. printers to install KBA’s Rapida 205 “super XXL” press. Another key to its success has been controlling relative humidity (RH) levels throughout its operations, from stock storage and prepress through printing and finishing.

Like many printers, Imagine! found that low RH causes a host of production problems that reduce throughput and efficiency. Maintaining consistent RH levels mitigates or eliminates most dry air problems.

As a result, in early 2005 the company installed an engineered humidity control system. The system includes 61 individual humidification units serving six zones, remotely controlled via a central programmable controller. The system ensures proper RH levels year-round throughout the company’s plant and offices.

Winter woes
In Minnesota, dry air is a problem in fall, winter and early spring. As temperatures drop and heating systems kick in, in-plant RH levels often become desert-dry. For instance, when 10°F outside air with 50 percent RH is heated to 70°F, RH drops to eight percent—printers typically experience production problems when RH drops below 35 percent.

Ideal conditions for printing exist when RH is 40 to 50 percent at 68°F to 72°F. Papers and substrates are more pliable and easier to handle, static electricity is sharply reduced and many other problems can be reduced or eliminated.

“Any time the heat was on, we had production problems,” says Jack Lothenbach, Imagine!’s facilities manager. “Static electricity caused paper to cling together, so the press and the folder sometimes took up two or three sheets at once. We had trip-offs, jams and jogging problems that slowed production and caused downtime.”

Double sheeting can damage presses, and while folders are less likely to have major damage, it slowed the line. Says Lothenbach, “If paper’s not moving smoothly, you’re losing efficiency.”

Imagine! faced other dry air problems. Paper and stock shrank, causing print and die registration problems. Brittle stock cracked or broke during folding and die cutting.

“We did the best we could at the time,” Lothenbach recalls. “We brought in hardware store humidifiers. They didn’t put out enough moisture. We didn’t know what our RH was, or how to keep it consistent.”

Improvement and issues
In 1993, the company installed its first humidity control system. It was an electric steam system, and it was a big improvement. “It reduced our static, stock shrinkage and breaking problems; we were very pleased,” says Lothenbach. But unanticipated baggage also was part of the deal:

  • High energy costs. Electricity was not an efficient way to heat water into steam. The more water being put into the air, the higher energy bills climbed.
  • High maintenance costs. The system required constant maintenance; including yearly steam cylinder replacement.
  • Employee comfort. The steam system produced unpleasantly warm, moist air: “Our plant felt like a rain forest,” says Lothenbach.
  • Condensation. Every system produces some condensation, but problems occured when temperatures fell below zero. Moist exhaust air from compressors, presses and other equipment froze in the ductwork, then melted and dripped onto people, equipment and printing.
The decision to diversify services in the late 1990s put the company on a fast track as a “one-stop shop” for customers. The company expanded into a building next door. Substrates like plastics and films required technical sophistication and tight humidity control.

Lothenbach explains: “Static is an inherent problem with these stocks; they’re not as forgiving as papers. If you’re going to avoid static, you have to provide consistently higher RH.”

A high-pressure solution
Lothenbach planned to install a steam system in the new building, but concerns about energy and maintenance costs led him to investigate alternatives. At Graph Expo he visited Husson Inc., exclusive North American distributor for Danish-based ML System a/s, a global supplier of high-pressure humidification systems. “A high-pressure system like ML’s is inherently energy-efficient,” he says. “It doesn’t heat water; it blows water through a nozzle and creates a cool fog or mist. Our energy costs would be much, much lower, and so would maintenance.”

Lothenbach figured that with two buildings, he could do an apples-to-apples comparison of the two systems. “Steam was effective but expensive,” he says. “The ML system would cost less to operate and maintain. We wanted to see if it worked as well.” When he learned his local electric company was offering rebates to customers who replaced inefficient equipment with high-efficiency equipment, the decision was a no-brainer. “We could save a bunch on energy and maintenance and earn a substantial rebate.”

In 2002, Lothenbach installed an engineered humidity control system from ML and Husson: 10 ML Princess humidification units in two zones linked to a central programmable controller and pump. If RH dropped below a 40 percent set point, Princess units added cool fog to the air until RH returned to 40 percent.

The ML high-pressure system proved as effective as the steam system in maintaining RH and solving production problems, with far lower bills for energy and maintenance. “I remember thinking: ‘This is the way to go!’” Lothenbach recalls.

Capacity and control
When Imagine! consolidated the company into one large building, energy costs associated with maintaining consistent RH control was essential. Lothenbach’s experience with ML’s systems convinced him that high-pressure humidification would be the most energy-efficient and effective answer. “Our ML system had done everything we’d hoped, but we owed it to ourselves to see if someone could do it better or cheaper,” he says. “We looked hard, but we couldn’t find anything as good. For instance, ML handled six zones and 61 humidifiers from a single PLC, with one pump and one reverse osmosis water system. No one else could do that. It saved a lot.”

In February 2005, Husson technicians installed the new ML humidification system in Imagine’s new plant. Thirty-five ML Princess units and 26 ML Solo units provide total system capacity of 4,000 to 5,000 lbs./hr. in six zones from paper and stock storage through prepress, printing, finishing and shipping. ML Solo units, designed for low-demand areas with lower ceilings, provide humidification in offices and prepress areas.

Each zone has its own RH set point: 30 to 35 percent in offices, prepress and kitting areas; 40 percent in storage areas; and 45 percent where eight flexo presses print papers, plastics and films. All are managed from a central site with a single pump and reverse osmosis water system.

“The system went in with no problems and it’s providing the control we need with the low energy demand and maintenance we expected,” says Lothenbach. “It’ll pay for itself in two years or less. It would be nice if everything else was as easy.”

About Imagine!
Minnesota-based Challenge Printing started in Bob Lothenbach’s garage in 1988. In early 2005, with nearly 500 employees and $87 million in sales, the company changed its name to Imagine! Printing Solutions and consolidated all of its operations in a new 425,000-sq.-ft. building in Shakopee, MN, near the Twin Cities.

Imagine’s growth has been driven by a belief in high quality, ever-expanding technical and production sophistication, and diversification of services. In the late 1990s, the company added new capabilities to its traditional advertising offset: pressure-sensitive labels on a variety of substrates; paperboard packaging; UV printing of plastic cards and plastic packaging; and POP. Today, those new services represent a substantial majority of sales.