Piece of (Sheet) Cake
Press developments make the dizzying heights of today's sheetfed offset a little easier to reach.
by Jessica Millward, Associate Editor
IT WAS ALMOST heartbreaking for the packagePrinting 2000 Excellence Awards Competition judges. Faced with about 50 sheetfed offset folding carton entries, they struggled to whittle the category down to only four winners; ultimately, only the slightest register flaws eliminated the competition. Such a resounding testament to the health of sheetfed offset prompts a question: What challenges do sheetfed printers face? And what solutions do press suppliers offer to enable those formidable folding cartons?
Challenge 1: Freedom of substrate
Four years ago, Hammer Lithograph ran nothing but paper at its plant in Rochester, NY. Customer and marketplace demands encouraged the company to branch out, says Director of Sales and Marketing Louis Iovoli, into the realm of BOPP. Though once considered a sheetfed no-man's land due to the substantial drying time required for inks, Hammer now prints sheetfed BOPP on all its Mitsubishi presses, including a 56˝ model and an in-line UV press. Using a proprietary formula for controlling press variables, Hammer uses sheetfed BOPP for high-profile jobs such as the Perrier wide-mouth water labels.
Mitsubishi's Ray Mullen, VP, sales and customer service, sheetfed presses, notes the company's carton presses employ a heavy-duty sheet guide system to prevent marking or smearing of board, and the Centralized Operator MakeReady and Control (COMRAC) console handles adjustments for stock thicknesses and sizes in about one-third the normal makeready time.
To ascertain the substrate is running correctly, and to statistically define mechanical characteristics of the press, Mitsubishi recently premiered the third generation of its DRA (Digital Register Analysis) service. DRA 2000, provided to press buyers and existing users, measures, within microns, precise sheet-to-sheet movement on every element of the press, then determines standard deviation and the adjustments necessary to eliminate imperfections.