UV light curing technology is a new technology in the green industry. It was once rated as an industrial technology with "5E" characteristics by the North American Radiation Curing Committee, which fully demonstrated the characteristics of this technology. The so-called 5E, namely Efficient, is highly efficient. UV curing can achieve complete curing within a few seconds, and the production efficiency is higher; Energysaving, energy saving, UV products are fast curing at room temperature, and their energy consumption is generally only 1/10 to 1 of thermal curing. /5;Environmentalfriendly, environmentally friendly, UV curing materials contain no or only a small amount of solvents, and the energy used for UV curing is electricity, no fuel or gas, and no CO2 generation, so UV curing is known as "green technology"; Economy, economical, compact UV curing device, assembly line production, fast processing speed, thus saving space, high labor productivity, UV curing process ensures thinner film, and has excellent performance to reduce raw material consumption, which is conducive to reducing economic costs; Enabling, wide adaptability, the UV product can be adapted to a variety of substrates, such as paper, wood, plastic, metal, leather, stone, glass, ceramics and almost all hard and soft materials.
Even though UV light curing technology has so many advantages, there are some unavoidable shortcomings. (1) UV mercury lamps have a limited service life; (2) UV mercury lamps consume a lot of energy, but the energy used effectively is not High, only about 20% of the input energy produces ultraviolet rays, while 20% is visible energy, and 40% is heat. From the spectrum of Figure 4, we can also see that in addition to the commonly used 300～ In addition to the 400nm waveband, there are many other wavebands, among which the infrared rays emitted will increase the temperature of the substrate, which can also better explain the reason why traditional UV mercury lamps are not suitable for heat-sensitive materials; (3 ) Although UV mercury lamps are environmentally friendly and environmentally friendly due to the absence of VOC emissions compared to solvent-based inks, UV mercury lamps also have some hidden pollution, such as the high pressure, high temperature and strong radiation of mercury lamps. , It is easy to cause the surrounding oxygen molecules to chemically react to produce ozone, and ozone not only has an adverse effect on the atmosphere, but also has a greater impact on health.
Compared with ordinary UV mercury lamps, the advantages of LED-UV are:
(1) Cold light source, no thermal radiation, low temperature rise on the surface of the illuminated object, solving the long-term thermal damage problem in optical communication and liquid crystal production, especially suitable for liquid crystal edge banding, film printing and other occasions requiring small temperature rise. The heat generation is small, which can solve the problem that the mercury lamp printing equipment heats up and the staff is unbearable. In addition, the LED-UV light source emits high-purity single-band ultraviolet light with almost no infrared output. It is a cold light source, and the processed parts will not be deformed due to heat.
(2) High efficiency: The light energy of LED-UV is highly concentrated in a certain ultraviolet spectrum with effective curing effect, and the actual use effect is comparable to the curing effect of traditional high-pressure mercury lamp UV light source with light intensity of 1000～2000mW/cm2 , Thereby shortening the curing time. The UV light of the traditional mercury lamp looks very bright, but the heat is very high, because its spectrum is very wide, the UV spectrum that is really effective for curing only occupies a part of the energy, and a considerable part of it is in the visible light range (miscellaneous Light) and infrared spectrum (resulting in heat generation), serious damage to the eyes of the operator and easy to thermally deform the processed workpiece.
(3) Ultra-long life: The life of LED-UV lamp is more than 10 times that of traditional mercury lamp, and the service life is not affected by the number of switching.
(4) Momentary switch, it can reach the maximum power UV output without preheating, and it can be restarted instantly after it is turned off.
(5) High energy, stable light output, good uniform irradiation effect, and improved production efficiency.
(6) The effective irradiation area can be customized, the length is from 20mm to 1000mm.
(7) does not contain mercury and does not produce ozone. It is a safer and more environmentally friendly alternative to traditional light source technology.
(8) Low energy consumption, the power consumption is only 10% of the traditional mercury lamp curing machine, which can save 90% of the power.
(9) The maintenance cost is almost zero, and the use of UV-LED curing equipment can save at least 10,000 yuan/set of consumables every year.
(10) Since the ultraviolet irradiation device and related supporting devices are very compact, there is no need for the large mechanical installation space and pipeline construction of the past, and the installation is simple and easy. It can be said that the LED-UV curing system further enhances the environmental coordination of the traditional UV curing system. LED-UV technology is an upgrade of the original UV technology.
As a new technology, LED-UV light source also has some problems at present. (1) Since the key technology of LED-UV is controlled by foreign countries, the price of domestic LED-UV lamps is relatively high; (2) Due to the limitation of technical characteristics, the light intensity of the current LED-UV lamp is not high, so that it affects the curing speed to a certain extent.