How low can you go?

Apr 1, 2008 12:00 PM, By Katherine O'Brien & Debora Toth

Makereadies have been drastically reduced over the past few years. Thanks to ink presets, automatic plate changing and other innovations, it's possible to switch from one job to the next in just 10 minutes.

For this feature, we asked some top press vendors to highlight technology that supports quick-turn, short-run work. Stay tuned — with Drupa around the corner we can expect more uptime improvements.

Faster, bigger, smarter

Doug Schardt, sheetfed product manager for Komori (Rolling Meadows, IL) says short-run lengths continue to decrease. While technology plays a crucial role in achieving maximum productivity, managers must do their part. “Someone with four or five older presses who buys an automated press typically doesn't ramp up their estimating or production standard to reflect the new addition,” says Schardt. “It's like a racehorse surrounded by Clydesdales.” Komori's customers can participate in “wellness checks” to ensure their presses are operating at peak efficiency.

Artificial intelligence (AI) (or advanced intelligence as Komori calls it) will continue to push presses to new levels of sophistication. “Presses can't think,” says Schardt, “But they can make choices based on data.”

Drupa is the coming out party for Komori's Lithrone SX40. Rated at 18,000 sph, the press can accommodate a 41-inch sheet. The press can start printing at 12,000 sph for significant time and paper savings. “When a press is accelerating, the ink and water aren't stable,” says Schardt. “At 12,000 sph, you're close to running speed, so [it makes sense] to start feeding sheets.”

Fully automatic plate changing makes it feasible to change six plates in less than two minutes, with nonstop plate removal. Further makeready savings are achieved via software that controls all inking functions, air and register presets.

Komori's On Demand Changeover Theatre will showcase KHS-AI on its sheetfed presses. A self-learning function memorizes any changes the operator makes to CIP4 download information and uses it for subsequent jobs. The press is “aware” of printing conditions and constantly updates itself to reflect them.

As variables change (for example, if rollers shrink), the self-learning function knows to adjust the ink key relative to the coverage required. “The result is that you're at target density very quickly,” says Schardt.

KHS-AI's Smart Sequence component automates color correction and adjustment. On a job-by-job basis, printers can choose the most appropriate of three preprogrammable automatic operations for complete press set up. These include de-inking, wash ups, pre-inking, plate changing and full automatic makeready so that, for example, the operator can select the pattern for “start of the day,” “job change” or “end of the day.”

For more on Komori's (www.komori-america.us) Drupa plans, see pg. 44.

Wash and go

At Graph Expo 2006, Heidelberg (Kennesaw, GA) debuted the Anicolor zoneless inking system for the 20-inch Speedmaster 52. Anicolor's keyless inking and anilox technology help it maintain a consistent ink film. An engraved anilox roller transfers ink from the chamber onto the plate form roller. From there, the ink is transferred onto a predampened, standard offset plate. A 4-color makeready on the press reportedly takes about seven minutes; the press is up to color in as few as 10 to 20 sheets.

“We are reducing makeready times to just hanging plates and washing blankets,” says Joerg Daehnhardt, director of sheetfed product management. “Once you've done those two things, you're ready to print.”

Anicolor incorporates elements of offset printing as well as flexography. “You're using standard plates, ink and a dampening unit,” says Daehnhardt. “On the other hand, you're using screen rollers as you would on a flexo or anilox coating unit.”

Unlike a conventional offset press that might require an operator to monitor 16 rollers, an Anicolor operator essentially deals with only with two rollers. “There's the screen roller and the form roller, and you're already at the plate,” says Daehnhardt. “It's a short ink path and train.”

Controlling the anilox roller's temperature is the key to ink metering. Operators raise or lower the temperature at the press console to transfer the desired amount of ink.