Keeping Up With Today's High-Speed Digital Web Printing Presses
Not long ago, many digital press vendors preferred to configure the digital press and finishing operations as somewhat separate entities. The main reason for this was that early on, high-speed digital presses (mainly production inkjet) struggled a bit to maintain consistent uptimes in the high 90th percentile. As such, digital press vendors didn’t want something connected to their system that might actually contribute to lower overall press availability.
But times have changed, and continuous technological improvements in inkjet have many presses running 24/7 with only stops for necessary maintenance. This is causing a shift in attitude on the in-line vs. off-line finishing debate. I deal with digital press print-and-finishing configurations every working day and I am seeing more proposed in-line finishing than ever.
What are the drivers? There is an innate desire now to offer the prospect a fast and flexible print-and-finishing solution that minimizes the labor needed to run it, and that can quickly change over to produce the variety of formats that customers require. This has a lot of appeal. But the print guys have it comparatively easy. They’re starting with, and handing over a printed web of, 20˝, 30˝, 40˝ or more. It’s us "bindroids" that have to make this roll of paper into a finished, sellable product. So an in-line finishing system must first cut and slit the web into the correct (untrimmed) format size for the product.
Or the web may need to be plow-folded in-line to create signatures of the correct size. The folded signatures may need to be edge-glued and pressed together to create a stable book block for the in-line perfect binder. For soft-cover perfect binding, covers need to be applied and the book block and cover need to be three-knife trimmed. The trimmer must be automated in order to read a cover barcode and trim the book according to the trim values captured in the barcode.
On top of the various web conversion functions, when in-line, the finishing system must be able to keep up with the press, and deal with the challenges of paper curl in the web, static issues and more. And presses continue to get faster, with 500 fpm or more fairly normal now. So, to be viable for in-line press-to-finish applications, finishing systems need high levels of automation, the ability to deal with various paper conditions and have a high degree of inherent reliability. But they’re getting there, and if the prospect can justify both the press acquisition and the considerable cost of a sophisticated in-line finisher, the reward will be a very capable high-speed, digital print-and-finish module that will earn its keep.