Designed to be used on thin paper, Toyo Ink's "FD LED Series" of LED-UV curable offset inks consists of a range of offset inks hard dried using ultraviolet rays produced by dedicated light emitting diodes (LEDs). Although the "FD LED Series" achieves the same level of ink performance as UV curable inks dried using conventional UV lamps, it is lined up as a next-generation technology due to the fact that it reduces environmental impact by conserving energy. It is aimed squarely at users focused on printing innovation.
First and foremost, UV curable offset inks are regarded as a particularly environmentally friendly printing system compared to conventional oxidative polymerization drying offset inks. They are characterized primarily by the fact that they do not include VOC (volatile organic compounds). Regular ink involves dissolving solids or high-viscosity resin in organic solvents, which are then released through volatile evaporation during printing. This gives rise to various issues that need to be addressed, including operational safety during the printing process and health hazards from residual solvents on printed matter. UV curable inks on the other hand use low-molecular organic compounds that produce photo-polymerization reactions under ultraviolet light as solvents, all of which are cured through polymerization during the printing and drying process, eliminating volatile evaporation of solvents.
Another key characteristic is instant drying. The rapid drying of regular inks involves heating with a hot-air dryer to speed up solvent evaporation, producing CO2 emissions from the electricity or gas used to heat the air. Although UV curing produces CO2 as a result of the usage of UV lamps, the amount of CO2 is greatly reduced.
The "FD LED Series" of LED-UV curable offset inks on display at this year's drupa2008 make UV printing even more environmentally friendly. They are also compatible with offset printers fitted with industrial LED-UV curing systems. The main benefits of LED-UV curing systems are as follows.
1. Compared to conventional lamps, LEDs consume much less electricity (roughly 1/4). This is due to the fact that, whereas UV lamps use an arc discharge luminescence mechanism, LEDs harness the electroluminescence of semiconductors. This effectively makes it possible to cut energy costs (electricity bills) and substantially reduce CO2 emissions.
2. As the light emitted by LEDs does not contain any infrared, the amount of heat generated in minimal. This makes it possible to print onto films and other materials with a low level of heat resistance and minimizes the effects of heat on the printer itself, which in turn means that fewer adjustments are required in terms of printing precision, reducing printer wear and tear.
3. As LEDs have a substantially longer life span when used as a light source element compared to lamps (roughly 12 times as long), they need to be changed much less frequently.
4. LEDs can be turned on and off instantly, thereby eliminating the need for warm up and cool down periods, as with conventional lamps, and improving operational efficiency.
5. As UV curing units are exceptionally compact, they don't take up lots of space when installed like conventional equipment.
The range of emission wavelengths for LEDs shows much sharper peaks compared to UV lamps. In an effort to achieve efficient drying properties based on this characteristic range, Toyo Ink has developed and optimized new pigments, resin monomers and photo-polymerization initiators to create the "FD LED Series". We believe that the collaboration between such new inks and systems will bring about major innovations in conventional UV printing systems, making it possible to save both energy and space.
It addition to showcasing the "FD LED Series" in its own booth at drupa2008, the Toyo Ink Group also plans to put on printing demonstrations as a sample exhibit in the booth belonging to Ryobi Limited (Hall 17, Booth A06), which has developed a printer equipped with an LED-UV printing system.
