Digital at the Finish Line
Digital print's short-run suitability presents a sizeable learning curve to converters' in-line finishing.
by Jessica Millward, Associate Editor
THOUGH COMMON WISDOM claims otherwise, sometimes you can have things both ways. That need has been, and will continue to be, the mother of invention regarding digital print finishing. The paradox: How do you pair in-line converting with a print process engineered for short-run jobs? The stops and starts of in-line have thus far greatly restricted much integration with on-demand techniques, but press manufacturers' discovery process has only just begun.
Thoro Packaging's hesitation to embrace digital technology in its folding carton facility is typical for printers. As Plant Manager Steve Jokela enumerates, one of the chief reservations his firm has in investing in digital is its ability to handle the in-line application of aqueous coatings, which are so common with its traditional offset jobs.
"The driving force is economics," Raymond Dickinson, marketing manager at Indigo America, summarizes concerning the choice of finishing system for the digital print process. And while suppliers differ on precisely where the digital print/in-line converting combo becomes infeasible, they all seem to agree on the priority of bang for printers' buck.
Dickinson relates digital press speed is the gating factor governing throughput in any in-line digital printing/converting configuration. Financial analysis leads most converters to conclude it makes little sense to allow the comparatively slow digital press to shut down for even one second of the time required for the converting set-up.
Nilpeter President John Little sees time/money loss in the die configuration of many digital presses. "The real problem is: How do you change a die with short-run work? If you're running 1,000 small, ten-up labels, it takes you longer to change the die than to run the material."
Unfortunately, the cost issue can run deep even with add-on, off-line converting machinery. Ken Daming, director of product management for Mark Andy, insists the major challenge to converting with existing equipment is its add-on nature. Because the press has its own web tension system, and the printer material must conform to another tension system for finishing, the need for a zero-tension loop in the web in between the two systems arises. The finishing line must then be capable of sensing an eye-mark on the pre-printed web to re-register.