Redefining Roll-Handling Equipment for Digital
Back in the 1980s and early 90s, large numbers of continuous web digital (toner) presses started to make appearances in direct mail and transactional print centers. The early roll-handling equipment for these presses was fairly simple—either re-winding the printed roll, or fan-folding it for the envelope inserters. I never thought of these systems as real bindery machines.
Fast forward to 2012. As high-speed inkjet printers increasingly displace their offset cousins, these postpress machines have definitely evolved. The manufacturers have realized that their units will have to acquire many more talents in order to maximize the digital production workflow.
The newer systems can now convert the printed web into “bindery ready” work, including:
• Web to Stack: Sheeting the web into multi-up individual book blocks at printers speeds of up to 800 fpm. In many cases, the blocks are conveyed directly to the binder through a series of buffer conveyors.
Book blocks can be produced by either slitting the web and merging the slit sheets, or cutting the web into multiple pages across the web width.
• In-Line Plow Fold: These units “signaturize” the web by plow folding a 20˝ or 30˝ web, then cutting it into individual stacked signatures. Signatures have always been considered to be easier to handle and bind than loose pages. Stacked pages can de-stack, and a single page or even multiple pages may not drop to register in the binder clamp.
Better yet, signatures (or loose sheets) are glued on the spine side of the book block to produce a stable block for binding. The production goals of these new machines are to be able to produce the “one-off” book in any size, and in any sequence.
• Roll to In-Line Fold: Unwinders can now run directly into a buckle folder to produce a variety of straight and parallel folded products at high unwind speeds. In addition, theses cutter sheeters can double-cut and chip-cut the web, as well as dynamically perforate specific pages within the web.
Dynamic perforation and dynamic punching are highly valued for billing remittance stubs, coupons, and reply forms for booklets.
• Roll to Saddlestitch, or Roll to Perfect Bind: Complete roll-to-stitch or -bind machines are now on the market and they can run either near-line (from a separate unwinder) or directly in-line with the printer.
These units compare more than favorably with their commercial bindery brethren, running at speeds of up to 7,000 saddlestitched booklets per hour, with a much lower manning requirement.
The finale of this story is that these postpress systems are literally a completely new category of bindery machines. They offer many serious finishing possibilities working directly with the printed roll or press. By eliminating the various “prep” steps, including folding and palletizing necessary in offset, they are blazing new frontiers in digital.
The future possibilities are exhilarating!