Quality Printing--Handling it Right
Proper web guiding, tension, and register control are basic ingredients needed for good print quality results.
PRINT REGISTRATION IS one of the first things packagePRINTING's Excellence Awards judges inspect when assessing the print quality of contest entries. For our expert panel, it's an easy variable to assess, and is used as an initial culling point to "separate the men from the boys." Entries will not contend for a first-place finish if they are not produced with good print registration.
This is clearly understood in the industry, but not everyone pays enough attention to some of the web-handling issues that directly impact registration, says Henry Rissier, president of AccuWeb (Madison, Wis.). "Poor registration is one of the most common print defects, and while many companies spend thousands of dollars on register control equipment, few address the root cause, which is often related to web control," he states. "Precise web guiding is a critical, but frequently overlooked requirement to producing superior print graphics."
There are innumerable variables that impact the ability to precisely control a web in its journey through a printing press. Many of these variables are directly related to the materials themselves.
"Webs can vary from vendor to vendor, roll to roll, and even within a roll," observes Jim Ward, VP of engineering for Martin Automatic (Rockford, Ill.). "The single most important step that one can take to fixing web problems is to avoid them in the first place. Choosing the right material supplier can have as much impact on a successful operation as choosing the right machine."
Bob Sarnelli, web tension product manager for ABB (Brewster, N.Y.), points out another big issue for package printers—the need to handle a wider variety of materials with the same machinery, from heavy to very thin and wide to narrow. This needs to be done while "still having perfect control over the process," he says. "Both the tension measurement systems and the newest digital drives need to have the widest operating ranges to meet the demands."