In the next few years, experts anticipate a marked growth in the market share of LED UV systems. And not without reason, because their particular advantages ensure cost-efficient and energy-saving production. LED UV units are ready to use as soon as they are switched on, and transmit only minimal heat to the substrate. These compact systems boast a particularly long service life. The LEDs can also be individually controlled, depending on where light is required on the substrate.
UV systems manufacturer IST METZ GmbH supplies both UV systems with medium-pressure lamps, and LED systems. The latest LED series is called LUV, and is available in different output levels. The LUV 80 model is designed for a working distance of 30 mm or more, and is used by companies Druckerei Hertle in Kirchheim/Teck and Häuser in Cologne, among others. Both printing firms spoke of their experiences with the system at an Information Day held by IST METZ at the end of November, on the subject of "LED drying in commercial printing".
Graphics firm Häuser KG in Cologne started as a letterpress and offset printing business in 1922, and today is the largest media production company in Cologne, and one of the largest in the whole of North Rhine-Westphalia. More than 80,000 customers around the world use the services of this large printing firm, including more than 1200 print shops. Over 1000 print jobs per day are completed in their entirety every day. The technical equipment comprises more than 50 machines and systems. Since 2003, Managing Directors Günter and Heiko Mazur have been running an online print shop called Druckdiscount24.de. Today, Häuser produces around 80% for the online platform, and 20% for traditional business.
Häuser decided to use LED UV technology in order that its printed matter would be more abrasion-resistant, and could be further processed immediately if necessary. On the Heidelberg Speedmaster XL 105 with two retrofitted LED UV feed units (one above the turning mechanism and one in the delivery chute) with water cooling, ink agitators are now used to maintain the correct flow characteristics of the UV ink. 13,000 to 15,000 sheets per hour are produced. As the printing inks are cured immediately and no powder is required, the sheets can be further processed without delay. There is significantly less paper waste and drying times are a thing of the past, saving several hours of production time. Based on the good experiences they have had with LED UV technology so far, Häuser intends to retrofit further presses in future.
Also this year, commercial printing firm Hertle installed an LUV 80 LED curing system from IST METZ. They were spurred to make this investment by one of their major clients – a publisher of greetings cards who found delivery times too long. For reasons of space, they decided to update their existing Heidelberg Speedmaster SM 74-5. At the Information Day, Managing Director Robert Hertle reported that previously the company had been compelled to allow three to five days for drying the cards. UV drying enabled them to dispense with this time, as well as the time and staff required to sort out paper waste. In addition, the upgrade meant they were able to add substrates to their portfolio. Mirror cards, plastic film and natural paper can now also be printed on in high quality.
The reports from these two users were joined by presentations from Epple Druckfarben about the properties of LED inks and varnishes, and from Fujifilm Europe on printing plate technology for UV printing. A presentation by IST METZ GmbH itself contained basic information on the advantages of LED technology in commercial printing.