SHEETFED DRYING/CURING SYSTEMS -- Running Hot and Cold

"One of the most cost-effective investments for a printer is to convert an old one- or two-color sheetfed press into a UV coater," asserts Prime UV Systems' Midlik. "The addition of UV dryers within an existing extended delivery or adding a UV conveyor extension at the end of a sheetfed press will enable the printer to apply UV coatings in-house. This easy UV retrofit can cost as little as 15 percent of the price for a dedicated UV coater."

Retrofitting is becoming very popular with the economy as it is, PRI's Douglas agrees. "Converting an existing press is expensive, but not as expensive as purchasing a new press with a UV system."

Sheetfed printers are not limited to UV technology when adding or upgrading the drying/curing capabilities of existing presses, but they may have to take physical constraints into consideration.

Adding an IR drying system to an older press can increase run speeds and cut turnaround times, thereby increasing the productivity of the press and improving print quality, says Oxy-Dry's Whitehead. "The main advantage to including a drying system as part of a new press installation is that the machine can be configured from the start to accommodate an integrated drying package, with an extended delivery allowing for sufficient dwell time."

Looking at the issue from another angle, William Fuchs—president of Fuchs-DeVries (FDV) in Mundelein, IL—contends that existing drying systems supplied with some sheetfed presses may not be adequate, even for water-based coating applications. "A substantial amount of high-volume hot air is required to set water-based coatings. Unfortunately, the systems supplied on some presses were designed with limited output of high-volume hot air," he asserts.

Inadequate drying capabilities on a sheetfed press can force a printer to reduce production speeds, rack loads to extend drying times and run with too much spray powder, in addition to limiting the type of coatings they can use and lowering the gloss levels they can achieve, Fuchs says. "These printers would clearly benefit by upgrading their existing systems."