Three Important Factors for Flash-Cure Units

Most screen printers are familiar with the flash-cure unit, and many shops use this piece of equipment as part of their production sequence.  A flash-cure unit is used during production to cure the surface of the ink only, at least, that’s what it’s intended for. It is important to understand the relationship between several factors that play a role in how well the flash cure gels the ink, and how to manipulate each to get the best results. Here are some tips from Kieth Stevens, recently published in Printwear, on what to watch out for when trying to set up the flash for optimal use:

• Timing:  Depending on the ink you are using, the flash time may vary from a couple of seconds to several seconds.  Some inks are designed to flash faster than others to minimize flash times during production runs. Typically, 2–3 seconds should suffice to get the ink surface to gel.  Be careful not to over-flash the ink, as it may become tacky after gelling and stick to the next screen.

• Temperature:  Different flash-cure units produce different amounts and types of heat depending on whether they are using quartz bulbs or infrared panels.  Each of these differences will cure ink at different speeds, so adjustments may have to be made in the temperature settings in order to get an optimal flash-cure on the ink you are working with.

• Distance:  This is the third determining factor in working with flash-cure units and may be one of the most important. The distance between the flash-cure unit and the platen will ultimately determine how much heat the platen receives, regardless of what the temperature of the flash-cure unit is set at.

These three factors work hand in hand in dialing in the optimal temperature and dwell time for the flash-cure unit to gel the ink.  Remember that parameters might also change during printing, such as the temperature of the platens rising from repeated exposure to the flash, so be sure to adjust any or all of the three factors accordingly. Consistency is the goal to strive for when using the flash-cure unit, so that the ink cures to the gel stage and will not stick to subsequent screens. Kieth Stevens has been a screen printer and industry representative for more than 35 years, and has been teaching screen printing for more than 12 years. In 2014, he won a prestigious Golden Image Award for screen printing from SGIA. Stevens is a regular contributor to International Coatings’ blogs. International Coatings manufactures a complete line of non-phthalate screen printing inks, including a wide variety of whites, specialty inks, special effects inks, color matching systems, additives and reducers. For more information on our products, please visit our website at www.iccink.com.