With growing popularity of UV-curing technology in the printing industry, a UVLED light emitting diode curing light printing, printing enterprises are paying more attention. Of UV LED light source, this paper discusses the characteristics and its analysis of the future development of the printing industry.
First, UV LED curing mechanism
Traditional UV printing refers to the photopolymerization initiator in UV inks, UV light irradiation, absorb different wavelengths and energies of ultraviolet light, to excited state and the formation of free radicals, or ions. Through Intermolecular energy transfer, prepolymers, monomers and polymers became excited, creation of charge transfer complexes. Crosslinking polymerization of complex particles constantly and eventually the ink curing membrane and adsorption in the printing process.UV LED (Light-Emitting Diode) light is ultraviolet light source technology towards more energy-efficient, and more environmentally friendly products, is able to launch a very narrow spectral half width of semiconductor electronics and electrical energy into light. Principle of photoelectric conversion, by note on the semiconductor substrate people, impurity-doped growth PN junction, and luminescence mechanism of edge effects Electroluminescent, collisions with electrons and positively charged in the move into light energy. Its radiation peaks single light energy with valid section of UV curing. Due to the many narrow spectral half width compared to traditional UV light source, high concentration of energy, low heat radiation more evenly. Use UVLED to reduce printing waste of resources, reduce the cost of printing, saving and printing production time, greatly improving production efficiency. Mutoh ValueJet-1626UH LED UV printer
Second, UV LED printing advantages
1. long life
Traditional UV light source will be replaced in about 1500 hours of work, frequent replacement of the light source replacement parts and may press curing failure caused by frequent and may also reduce the efficiency of printing press operation, printing enterprises normal production. Life of the UV LED light can reach more than 8 times times the traditional UV light sources, up to 12,000 hours, and not under the influence of switching times. According to the theory luminescence, UV LED light source power on only in one direction, forward bias, when electric current passes through it, electrons and holes in the compound and emit light, ensure the stability of the light sources, light decay rate is much smaller. In after 8,000 hours of work, for example, luminescence intensity can also reach its maximum power of 95%.
2. energy saving
Conventional UV printing, print to open the preheat light systems before, light power to open more, wait longer. Some printing enterprises in order not to delay the printing time as well as maintenance of UV lamp service life, often choose not to close the exposure system, keep it light, light sources caused considerable waste. UV LED light source according to its own characteristics of moment to convert electrical energy into light, low pressure starts, so there is no warm-up time to reach maximum power output. 80% per cent of the curing light for ink curing light energy. While low luminance, small heat. On very low light intensity of traditional UV light source can be achieved the same effect, you can reduce the power consumption of 70%~80%. High energy efficiency. And when it is not needed it can be closed, further reducing energy consumption and costs.LED UV Magenta Ink
3. suitable to a wider
Traditional UV light, heat, and thermal deformation of printing materials. UV LED is a cold light source, is issued by a single wavelength, infrared light is not included, no heat radiation and does not produce too much heat. So using UV LED light source can significantly reduce the heat generated by the curing process, appearance will not damage the substrate base material. Good printability for example cannot operate in conventional UV equipment for heat-sensitive film substrate, in the UVLED printing mode can better printability. Now fast-growing label printing, print faster and faster, the printed substrate and thin. If the heat is too high, will happen in the heat of the substrate reaction making it wrinkled, affect the quality of the product. Using UV LED printing greatly reduced defective rate to ensure printing quality and quantity within the duration of the task.
4. protecting the environment
Now UV printing in the printing industry’s market share increased significantly. Some printing enterprises in the use of high pressure mercury lamp as UV curing lights. Printing plant after using it takes human and financial resources to scrap their mercury emissions. If not timely, it will penetrate into the surrounding environment. Very low mercury content in discharged waste water, do not directly cause harm to the human body; but the microbes can absorb mercury compounds, and transferred through the food chain, eventually absorbed by the fish and shrimp and other seafood and stock up. Mercury transformation in vivo and drain very slowly, to long-term preservation of the body. If eating seafood, which can seriously affect your health. UV LED illumination system is free of mercury and other harmful chemical elements, work will not cause any pollution to the environment and human.
Three, UVLED print Outlook
Although the UV LED technology in civilian industries has been showing its many obvious advantages, but a late start in the printing industry. Now UVLED the market is growing at a rate of 20% per year, by 2020 the market could reach $ 350 million. But currently UV LED light of price also in high level, a group UVLED lamp of price basic to a hundred thousand of Yuan, than traditional UV lamp your have more, and and of supporting of UV LED ink, to in very narrow of spectrum paragraph select for of photosensitive agent, so more with specific sex, cost than traditional UV ink high 20% around, price also to than traditional UV ink your out many.
Most printing companies now feels updated equipment and raw material costs, while environmental consciousness is still relatively weak, the lack of comprehensive consideration of the social, economic and domestic environmental protection lack of implementation of laws and regulations are not sound enough, most printing companies still insist on using traditional UV light source.UV LED printing is in line with the packaging and printing industry the current advocates of efficient, energy-saving, environmentally-friendly development, taking into account rising industrial tariffs and environmental regulation and printed green certified pressure increasing, the popularity of UV LED printing is a general trend. As the printing industry in the future development of environmental protection and leaps in printing technology breakthroughs, UV LED illumination system will continue to mature, estimated cost of UV LED light sources will not be high. Predictable, UV LED printing in the printing industry in Flex just around the corner.