It's a Wide, Wide World
Wide-web press manufacturers are adding features to make
these big guys more nimble and easier to operate.
By Tom Polischuk, Editor
WIDE-WEB PRESSES offer many scale advantages for package printers that can provide great returns for their businesses. The downside, however, is that this scale also translates to higher costs for downtime, waste, and job changeovers.
Press manufacturers know well the issues faced by their customers. In addition to print quality and material usage, Jim Coddington, vice president for BHS Printing Machinery, sites productivity for short and long runs, and flexibility of the process as important issues for operators of wide-web presses. Features incorporated into BHS presses to address these issues: automatic laser-measured impression adjustment to compensate for varying substrate thickness; job changeovers with plate and anilox sleeves measured in minutes; and a Promet job management system that stores all critical press positions for future recall.
Frank Passarelli, Product Manager for Bobst, spells out some of the press variables that can be automated and preset for improved press operation. These include web tension, dryer temperature controls, ventilation system, pressure settings, doctor blade settings, and registration controls. "All of these will greatly influence the press repeatability results and contribute to a reduction in waste levels," he states.
Press operation
Today's wide-web presses include many state-of-the-art features that are designed to improve reliability and reduce operator intervention. Servo drives are just one example. The advantages these systems have over conventional mechanical systems are many. Gary Owen, director of marketing for KBA, says that the use of shaftless couple drives has delivered significant efficiency gains from improved color registration, reduced start-up waste, and improved press set up.
Another development discussed by Hans Deamer, president of Windmoeller & Hoelscher (W&H), is the use of cantilevered changeover sleeves. "Developments in plate cylinder sleeves has been rapid," he states, "and today's designs are vastly superior to those of only a few years ago. However, at about 52", these sleeves become too heavy and bulky for one operator to handle."
Sleeve durability and accuracy is also an issue raised by Deamer, whether using a composite plastic sleeve or a bridge sleeve system. Composite plastic sleeves have a life of only three to four years, and bridge sleeves offer a partial solution, but are heavy and difficult to handle. So for cantilevered sleeve presses, Deamer sees future developments that improve the durability of plates on the anilox roll sleeves, make plates light enough for use with wider machines, and provide low-cost handling systems.
In addition, Passarelli says that second- and third-generation designs will make further enhancements in areas such as servo drive systems, memorization of job settings, automatic register systems, and print cylinder wash-up and changeover systems.
Presses to consider
PCMC's Avanti is an 8-color flexo press designed for quick changeovers of plate and anilox sleeves. It's available in a 50" web width with AC servo motors that allow an infinitely variable print repeat length between 14 and 30 inches. It runs at speeds up to 1,000 fpm and can run solvent and water-based inks and coatings.
At an open house in April, KidderComexi demonstrated its Comexi FP 1808 Direct Drive Gearless Press. This 8-color flexo press features an AC servo motor that directly drives the impression cylinder. All of the plate and anilox drive motors are electronically synchronized with the impression cylinder. It is available with a fully automatic wash-up system, a dedicated sleeve system for plate and anilox rolls, auto registration, and print defect detection.
Wolverine Flexographic Mfg. Co. offers the CIRE Series of central impression presses that is available on 4-color or 6-color frames. The presses are 30 to 60" wide, with repeat lengths ranging from 14 to 50 inches.
Inta-Roto's extra-wide flexographic presses are available in one to six colors in either central impression or stack-type configurations. Features include an automatic wash-up system, sleeve-type plate cylinders, gear or gearless drives, and repeats of 60" or more.
W&H's ASTRAFLEX® Series of 8-color CI flexographic presses are available with geared or gearless drives, in widths of up to 75 inches. Enhanced with the ECO PLUS® package, the press includes automated plate cylinder and anilox roll changes, an automatic ink supply and wash-up system, and the ability to changeover unused ink stations while the press is running. ASTRAFLEX has been expanded to include a 10-color version.
