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.
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."