On April 13, 2015, an EU ban came into force that prohibits the use of mercury in lighting, causing concern among some in the wide format print industry that printers using mercury vapo r for ink curing will also be affected. While it seems this is not on the cards just yet, the EU’s focus on the metal suggests it may be worthwhile looking at the alternatives when choosing new equipment.
 
Luckily, other curing technology offers more benefits than just escaping the attention of Brussels. Because LEDs are solid-state devices that use semiconducting technology to produce their output, they do not share some of the drawbacks of traditional mercury lamps.
 
LEDs have a much longer lifespan than a traditional bulb: 20,000 hours for an LED vs. 800-1000 hours for a mercury-arc bulb. The diodes in an LED also provide consistent output throughout the life of the lamp. While a mercury bulb will show a marked decrease in output intensity over its lifespan, an LED will provide the same level of power through its entire life.
 
LED technology also allows for the lamps to be switched on and off as needed with no warm-up or cool-down periods required, further enhancing their energy saving properties. Much of the efficiency in LED lamps is due to the fact that 100% of the energy emitted is used for curing. LEDs are monochromatic, which means that all of their energy is emitted in a very narrow spectral band; typically 395 nanometers. We also see LED systems emitting their energy in the 365nm or405nm range. With mercury vapor lamps, a great deal of the energy emitted is lost to the visible spectrum or to heat, neither of which aid in the curing of the deposited material.
 
LED lamps have proven to have tremendous benefits over the mercury-arc lamps that have traditionally been used for UV curing. Several inkjet printer manufacturers are claiming power reductions of their UV curing systems in the 65%-75% range. Studies done by Nazdar on LED/UV curing system in the screen print industry support the assertions made by inkjet printer manufacturers.
 
Beyond the reductions in power consumption by the curing systems, studies have also shown a reduction in the energy needed to cool the print environment when LED lamps are used in place of mercury-arc lamps. While not as significant in the enclosed confines of an inkjet printer, the reduction in overall heat and ozone produced can lead to an additional energy savings in the shop environment.
 
Furthermore, most machines can be wired into standard electrical current, making installation easier and cheaper, while print companies report shorter drying times for LED-cured output compared to prints completed on mercury vapor machines.
 
Many users are finding they can use thinner and more heat-sensitive substrates thanks to lower temperatures, thus reducing material costs. While LED lamps do produce heat, that fact that an LED is very similar in its construction to a printed circuit board allows the use of heat syncs, air cooling and even water cooling to help draw heat away from energy emitting components of the LED. This allows for very little of the heat generated by the LED unit to be transmitted to the substrate being printed.
 
For inkjet printers producing jobs on heat sensitive films or on substrates that tend to buckle under the high heat of mercury-arc lamps, LEDs are a technology that can greatly improve the efficiency of the print operation. To businesses and customers looking for cheaper, more environmentally friendly products, there are plenty of advantages.
 
From the perspective of an ink manufacturer, Nazdar sees great growth potential in LED curable inks and is focusing a great deal of its research and development efforts on LED curable inks. Nazdar has been involved directly with a number of printer and printhead manufacturers to fine-tune LED curable inks for use as OEM and white-labeled inks.
 
Nazdar has developed a wide range of inks for use with LED curing technology for digital, screen and narrow web printers. Each are designed as plug-and-play, color-matched alternatives to OEM inks for specific printer models or series, enabling users to convert to lower-priced, high-quality Nazdar ink with no flushing or other downtime.
 
For digital printers, Nazdar 260 Series inks are ideal for POS applications using substrates such as reinforced vinyl banner, pressure-sensitive vinyl, styrene, foam board, coated paper, fluted polypropylene and digital-grade polycarbonate, thanks to excellent adhesion, flexibility and chipping resistance. Designed for use on LED curing printers at normal conditioned room temperatures, the inks make for a more pleasant working environment while producing prints with consistent, high-intensity colors with low colour-fade.
 
UV LED can also be used with screen printing, as Wisconsin’s Empire Screen Printing demonstrated in 2011 with the world’s first UV-LED curing screen press, utilizing Phoseon and Kammann equipment and Nazdar inks. The process does not emit harmful ozone nor as much heat as mercury lamps, resulting in a cleaner, cooler environment and prints on thinner materials. According to Empire Screen Printing, it is also possible to retrofit UV LED kit onto small-format screen presses.
 
Nazdar 2600 Series, 2300 Series, 2400 Series and UV LED Air Texture Clear inks are designed to work with LED-curing printers to produce POS and graphics, packaging and textured items. There is an even wider range of UV LED flexo inks for narrow web printing, formulated for tag, label and packaging applications.
 
Nazdar is also happy to work alongside OEM manufacturers who are developing LED-equipped printing systems, taking complete responsibility for the ink aspect of the development to create top-quality ink formulations engineered precisely for the system and its complementary substrates and applications.
 
Print businesses considering a move to UV LED inks can also be safe in the knowledge that they have the support of experts, through Nazdar’s Ink Answers support service. Users can send the company their queries via the email address [email protected]and will receive an answer from the person on Nazdar’s technical team who is best equippedto deal with that particular question. Around 3,000 emails are sent to Ink Answers per year, covering topics including the best inks for specificapplications,local ink suppliers, regulations on safety and disposal.
 
The merits of UV LED inks are many, and there’s never been a better time to discover them.
 
Rich Dunklee has been with Nazdar Ink Technologies for just over fiveyears and serves as the global market segment manager for UV Inkjet products. Heis tasked with the development and marketing of new UV inkjet products, and the product management of Nazdar’s portfolio of UV inkjet inks. Dunkleehas spent the last 25 years in the print industry, mostly in the offset print sector.