Most of what is written about inkjet printing is focused on what happens at the print step. As companies evaluate their options for migrating from toner or offset environments, they may be thinking about web width, print speed, and ink application. What happens to the printed output may not be given the same level of consideration. That could be a problem.
Finishing issues can surface when an organization changes printing technology. Some of those matters can keep an operation from realizing the productivity benefits they sought by changing to inkjet. Other potential issues affect the ability to take full advantage of the flexibility and creativity inkjet provides.
Faster throughput on the printer won’t be useful if the finishing equipment can’t keep up. This is immediately obvious if pages are finished inline, but it might be a problem with nearline configurations as well. Printed output waiting to be finished is exposed to fluctuations in temperature or humidity, which can cause edges to curl. Jam rates on the finishing lines will increase, resulting in reduced throughput and more reprints.
Inkjet printing involves the application and removal of water. Shops that formerly had no problems with waterless imaging processes might experience a different outcome with inkjet. Dealing with wavy or curled pages caused by uneven evaporation can force inserter operators to slow the equipment. Uneven sheets can also bring about inconsistent folding, which prevents addresses from aligning properly in envelope windows, increasing the number of rejects and reprints.
Areas of heavy ink coverage may not dry sufficiently. Paper transports on finishing equipment can cause smudging, or ink can transfer to belts and rollers, contaminating other pages with ghost images. If the workflow must be changed to add more drying time, productivity will suffer.
Paper handling on finishing equipment must be evaluated along with choosing an inkjet press. Though paper choices for inkjet presses have been constantly expanding, characteristics of supported inkjet paper may not match finishing equipment specifications. Paper grain, weight, stiffness, or smoothness can affect finishing equipment abilities to feed, fold, or insert.
If roll-to-roll printing is the plan, document operations managers must be sure there is enough room in the shop for stationing roll unwinders and cutters at the finishing equipment. Redesigning the layout or replacing several slower finishing lines with fewer but faster machines might be necessary to free up space. Printed rolls must be moved from the inkjet presses to any piece of finishing equipment without disrupting production in progress.
A white paper workflow allows print operations to combine several small jobs into large print runs. This strategy improves productivity on the press, but requires solid document integrity and tracking capabilities in the finishing operation. This is especially important when sorting for postage discounts before printing. Upgrades to finishing equipment may be necessary to ensure all items are accounted for and each piece is properly assembled.
Another advantage of white paper workflow is the ability to apply variable perforations. The finishing equipment must be able to handle horizontal and vertical perforations at different places on the pages without causing paper to jam or separate. Reviewing finishing equipment specifications regarding the location and density of perforations is recommended before committing to press-attached perforation units.
Document operations may plan on taking advantage of a white paper workflow to generate a wider variety of page sizes. Obviously, the finishing equipment must process the range of width, length, and orientation of the printed documents. In shops with a mixture of document sizes, finishing equipment that can be automatically configured to meet the requirements of each job can save time and reduce mistakes.
Switching to inkjet can affect many parts of a document workflow. Finishing is an important area that should be included in the plan.
Mike Porter is President of Print/Mail Consultants. He helps his clients get the most from their document print and mail centers and prepare strategies for the future. Visit www.printmailconsultants.com and sign up for his free newsletters written especially for document industry professionals or follow on Twitter @PMCmike.