Extra! Extra! Extra!

Thanks to servo and sleeves, today's wide-web presses are a far cry from similar technology produced only a few years ago.

THE LAST FIVE years have seen significant innovation in technologies in nearly every arena.

The first commercially-available hybrid car was introduced in North America. DVD players were given the capability to record. A camera was added to cell phones—anything and everything that could in some way give consumers extra benefits and capabilities has become the goal of R&D departments, and not just in the car and electronics industries.

Wide-web presses have also undergone advances. The shift in technology incorporated in wide-web presses over the last half-decade has been nothing less than "dramatic," said Hans Deamer, president, Windmoeller & Hoelscher Corp.

A move to gearless engineering and advances in sleeve technology are two of the biggest changes in wide-web presses that are helping printers stay competitive. But a change in the design of both flexo and gravure presses has opened up press engineering to the imaginations of the designer, said Kurt Flathmann, vice president/sales manager, Fischer & Krecke.

"Tremendous advances have taken place in the last five years relating to press technology," he said. "Advances in AC servo drive technology—combined with advances in sleeve technology and lightweight, rigid materials such as carbon fiber—have combined to enable the traditional central impression press to take a leap forward in evolution. These advances enabled press manufacturers to start their press design with a clean sheet of paper, no longer bound to previous designs, but limited only by their level of innovation and far-sightedness."

Servo's contribution

Gearless innovations have aided both gravure and flexo wide-web printers in achieving quality that was impossible with previous press technology. Printers, like their customers, want better repeatability, reliability, and consistency in their end results, and wide-web press manufacturers have delivered with servo technology, said Tom Jacques, marketing manager, Paper Converting Machine Co.

Specifically, Jacques said, "Advances in print deck drive technology, such as those featured on third- and fourth-generation gearless flexo presses, have greatly enhanced the stiffness and registration capabilities of wide-web gearless presses."

What makes gearless technology so beneficial is its ability to potentially automate some print functions—such as impression setting and color density—and to eliminate some of the tweaking operators have to do with older presses. This will increase accuracy and repeatability in print jobs, Jacques said.

Steve Lekan, director of business development for the southern United States, Comexi, agreed. "Certainly the advancements in gearless press technology—increased production speeds, faster changeover features, more automation to make operator intervention minimal, totally integrated electronics, modem support, and technical service locations throughout the country—have vastly improved productivity and uptime," Lekan said.

So, what exactly about servo drives makes all these benefits possible? Today, servo drives are almost universally used for plate cylinders, which eliminates bull gears, plate cylinder gears, splines, and other bushings, Deamer said. And without all these components, the usual problems associated with them are also eliminated.

Sleeve it

Along with servos, sleeves have revolutionized wide-web presses. Not only are sleeves lighter and easier to handle than cylinders—in most cases— they can be cheaper, too.

"Fast-change flexo sleeve presses have also become virtually universal, while there still is a significant market for servo driven 8- to 10-color automated cylinder presses fitted with robots, servo drives, automatic deck positioning, and automatic impression setting, especially where very high production speeds of up to 2,000 fpm, long runs, and wide widths are involved," Deamer said.

While sleeves have yet to become widespread in gravure due to general reluctancy and on-going perceived issues with engraving of the sleeves, they've taken a firm foot-hold in flexo presses. Most flexo presses built today incorporate mechanics designed for sleeves, Flathmann said. "The new sleeve-based presses feature a window in the side of the press frames that enables operators to slide sleeves off the support mandrel on a cushion of air through the press side frames, without hoists or robotics required, making equipment less expensive and far more convenient," he said.

There are some drawbacks to sleeves, however. There are still problems with durability, handling, accuracy, balance, and longevity, Deamer said. Also, while sleeves are lighter than traditional cylinders, at widths over 60˝, they are still too heavy for an operator to handle.

In addition, printers without the capital to spend on a new piece of equipment may find themselves losing customers. According to Deamer, sleeves and servo drives combined have made flexo presses older than 10 years "obsolete and non-competitive in today's aggressive price-pressured market place."

Presses today vs. yesterday

The innovation that has taken place in wide-web presses is helping printers deliver the kind of quality their customers demand and the kind of quality they need to compete in the industry, Jacques said. "The flexibility and low maintenance inherent in today's gearless presses allow package printers to compete effectively against converters with older technology," he said. "Also, these presses allow streamlined work processes, which further enhance [printers'] competitiveness."

But no matter how much the technology has progressed or how the market place changes, the laundry list of key words that printers want in their equipment has stayed the same. It's still about throughput, quality, and dependability, said Rick Ruenzel, director of business development for the Midwest, Comexi. "[The list includes] productivity, with increased speed, ease of changeover, and operation; quality in the equipment and in the printing; reliability of both the press and the technical support of the press; and of course, price. All of these items translate into a relative economic value," he said.

It may seem like an exaggeration that presses today are really that much more advanced than presses from a few years ago. However, they really are, Flathmann said.

There are many reasons for this. "The tooling changes associated with a specific job are reduced. The inventory of plate cylinders is vastly diminished, and replaced by less expensive sleeves. Gears are eliminated, as are keyways, splines, hubs, etc., reducing job costs further," he said. "Changeover times are decreased, enabling more throughput from a single machine. Increased press speeds also contribute to more throughput. Greater flexibility allows for the same machine to run short-run jobs more quickly, run wide-web jobs more easily, and run long-run jobs at higher speeds. This combination allows one machine to potentially be as efficient as two to three older presses, equaling their throughput, improving their print grade and quality, and increasing press speed—all while reducing waste and set-up times.

"Printers have been able to replace older equipment, reduce staffing, increase throughput, improve grade and quality, and reduce waste—formidable accomplishments that significantly contribute to overall profitability of any plant. The advantages are clear," Flathmann added.

by Kate Sharon

Associate Editor