"The old concept of putting lots and lots of IR emitters in the system and literally cooking the sheet with IR energy is simply not effective on state-of-the-art, high-speed printing presses," Bonallo says. "Achieving curing and/or drying at press rated speeds requires 'smart' system technology that will allow the infinite control of drying energy to the substrate. Although we configure our systems with power outputs that provide rated press running speeds on a wide variety of substrates and levels of ink coverage, nonetheless we like to dry/cure using only the amount of energy necessary to do the job.
"Running at that level normally results in cooler substrate and load temperatures," he continues, "thus having less effect on the potential of effecting the dimensional stability of the sheet, which can affect sheet-to-sheet register on subsequent press passes or off-line finishing, as well as image registration on second pass or second-side printing."
technotrans america recently signed an exclusive agreement with IST Metz, which allows its sheetfed division to be the exclusive representative for IST Metz UV curing systems in the United States and Canada. technotrans provides a line of infrared hot-air thermal drying systems for sheetfed ink- and water-based applications, as well as both hybrid and full UV.
Honle UV America's customers are looking for highly efficient UV curing systems that allow them to successfully cure UV inks with coatings at fully rated press speeds up to 800 fpm in flexo presses, according to James McCusker, president.
"Film creates more challenges when curing with UV," he says. "Customers are now demanding 'cold mirror' technology when processing supported and unsupported film, due to the thermal sensitivity of the stock."
Honle's Advanced Cold Mirror (ACM) UV unit provides a higher peak intensity, while reducing web temperature by 70 percent.
Eltosch North America offers a number of drying/curing solutions. The UV Interstation can be placed after a print unit or over a perfecting unit and is available with dichroic reflectors and stepless power control. The UV End Cure can be used with the Interstation or as a standalone final UV cure, while the Mega System is a combination of IR and thermal air that accelerates the drying of aqueous coatings at maximum speed.