Big and Better

Package printers are reaping the benefits from productivity enhancements that are built into today's wide-web flexo presses.

BIGGER IS BETTER! That's a motto that suppliers of wide-web flexo presses wish all package printers would adopt.

But bigger also conveys images of heavier, more cumbersome, and slower—all qualities that today's nimble, agile manufacturers can't afford to be. And they don't have to be—because today's wide-web flexo presses are getting better and better in many ways that make them "lighter on their feet."

Steven F. Lekan, director of business development for Comexi America, gives credit to flexo printers for helping drive the positive changes. "Flexographers are known for their willingness to embrace and adapt to new technology. This desire to strive for being better has given the incentive to machine builders to consistently develop new technology to satisfy the demand."

While there have been numerous advancements in flexo press technology in the last several years, Lekan stresses the "aggressive push towards efficiency and operator performance" that has occurred most recently. The end result is increased production with reduced waste. "It is not uncommon to hear that new press performance can replace as many as three or four older presses," he says.

Press enhancements

Many of the recent improvements in wide-web flexo press technology fall into the category of press controls and peripheral equipment. The objective of many of these enhancements has been to either reduce waste (which can accumulate real quickly on wide presses) or to improve the handling of the larger machine components. In either case, the net result is increased productivity from faster changeovers, and set ups, and start ups.

As an example, Lekan points to a pre-register system from Comexi that puts all print stations in register within three revolutions of the central impression (CI) drum. "Prior technology relied on the operator or optional features in a video camera that was tied into the deck controls," he says. "The result is minimal operator intervention and minimum waste."

A standard feature on most of today's high-performance presses is automatic wash-up of the doctor blades and anilox rolls/sleeves. The impact on changeover and makeready times can be significant. "A complete 10-color press can now be cleaned up in as little as eight minutes—automatically," says Lekan.

For drying, PCMC's eXtreme™ drying system can improve performance on a variety of substrates and applications, including different inks and low-gauge, extensible films. It uses high-velocity, low-pressure, compressed air to improve heat transfer and provide better air movement in the boundary ink layer. This can result in higher speeds, lower retained solvents, and better print quality.

Hans Deamer, president of Windmoeller & Hoelscher, notes the continual efforts by W&H to improve the reliability and productivity of its presses. These efforts have most recently resulted in a new automated sleeve-handling system, called PORT-A-SLEEVE, and EASY-SET, a fully automatic impression-setting system.

PORT-A-SLEEVE is a fast, semi-automated and pre-programmed system for sleeve changeovers. With the use of simple programming, the sleeve cart is automatically moved to the right machine position for the operator to change the sleeve.

EASY-SET is an interesting concept. It automatically adjusts the inking and impression nips when starting a new print design, says Deamer. The impression is measured across the entire web width, along with the real-time print results. This forms the basis for impression adjustments on both sides of the plate cylinders and anilox rolls, which are done automatically. The system does not use any printed marks for the impression adjustment.

"EASY-SET dramatically reduces impression setting time and waste, while at the same time allowing the press to run at high speeds during the automated adjustment process," notes Deamer. It can be used with transparent, opaque, and reflecting materials.

Fischer & Krecke introduced its Flexpress line of sleeve-based, servo-driven presses at drupa in 2000 and has been continually improving performance. The productivity enhancements from such state-of-the-art presses can be substantial. One of its customers, Ultra Flex Packaging, replaced four presses that ran 24/7 with two Flexpresses that run 24/5.

F&K continues to develop productivity enhancements for the Flexpress line. Kurt Flathmann, VP sales and marketing, reports one of its latest additions, Flexpress Control, was jointly developed with Advanced Vision Technology (AVT).

The system looks at a printed mark using a video camera and simultaneously sets impression for all print units. "Flexpress Control dramatically reduces set-up time, waste, and labor requirements," says Flathmann. It can be combined with AVT's pRegister automatic register pre-setting and control system to automatically register the print units using printed register marks.

Another recent introduction from F&K is its Flexpress Motion®, a logistics system that includes material handling hardware, robotics, software, and computer controls. Flathmann says that Motion closes the loop for flexo printers by bringing the isolated peripheral technologies seamlessly into the flow of production.

"Our engineers looked beyond designing a press and considered every practical aspect of a printing operation—every component involved in the delivery of a finished job—integrated it all and delivered a system that complements our press speed and our rapid changeovers."

The Bobst Group has developed a new engineering concept called Universal Deck. "The Universal Deck concept is radically innovative, as it affords the freedom of building around different solutions that can be implemented at any time after the press is installed, to conform to the converter's changing needs," says Frank Passarelli, product manager, printing and coating for The Bobst Group USA. An example of this is the ability to transform a CI flexo press from eight to 10 colors.

The Universal Deck approach was developed to address the converters' needs for flexibility and productivity, while addressing the uncertainties that arise from the constantly evolving packaging markets. "By integrating such printer needs, Schiavi developed the Universal Deck solution to give a concrete answer to all major processes and printing difficulties," says Passarelli.

In addition, he notes that in-line solutions, including downstream units such as lamination, can be economically retrofitted to an existing Schiavi CI Flexo Press that is built with the Universal Deck concept. "In-line and/or downstream units transform the press from a standard printing press to a production machine," he says.

Helping out the operators

To help operators handle the workload that comes with the increased productivity, press suppliers are looking at all aspects of the work that's required to keep these large machines up and running.

To reduce labor and operator fatigue in handling rewind rolls, Comexi has developed an automatic rewind roll unloader. "With on-press slitting capabilities and short runs, small rolls are often produced on the rewind very quickly," says Lekan. "To assure maximum production speed, this system automates the rewind roll unloading, and prepares the shaft for the next roll automatically."

Press suppliers are also providing the information systems that operators need to make effective brand changes and to keep the presses up and running. Passarelli points to job recipes for repeat orders that reduce machine set-up time, while Flathmann highlights the ability to safely set up non-operational print stations for a new printing job while another job is still running on the press.

Human machine interfaces (HMIs), typically in the form of intuitive touch-screen controls, are high on the list of technology enhancements that have made life a little easier for operators. Comexi's systems include bi-lingual touch-screen interfaces to address the needs of a diverse workforce. "Operators can be trained quickly since most people are accustomed to standard Windows screens and diagrams allowing look-and-touch control," says Lekan. "Of all the new technology integrated into today's presses, this is the feature most cited by operators as making their job easier."

Perry Lichon, president of Retroflex, reports that the addition of state-of-the-art HMIs to its Fox Series of wide-web flexo presses has allowed operators to experience a higher level of control and flexibility. "It has allowed for a much cleaner installation and faster set-up times," he states. "When HMI is combined with features such as a flush system for ink wash-up and sleeved rolls, the operator is able to achieve greater productivity."

Although Lichon believes that operators embrace the new technologies being offered in today's presses, he cautions against taking this for granted. "All of these state-of-the-art features require continuous operator training to be sure you are operating the equipment at maximum efficiency," he says.

New market opportunities

With the significant reduction in changeover times for wide-web flexo presses, package printers are able meet the needs for shorter runs that are being driven by the market. The flexibility that this provides will be critical for success as printers look at new business opportunities.

This affects how both suppliers and printers view their press assets. "The difference between press controls and press peripherals is quickly becoming a fine line," says Lekan. "What once might have been an option or a peripheral only necessary for a specific application, is fast becoming an integral part of all presses. This is especially beneficial to our industry as we continue to strive for versatility."

by Tom Polishuk

editor-in-chief