In recent years, UVLED curing technology has been highly concerned all over the world. In many applications, UVLED light source is used to replace the traditional mercury lamp. UVLED is a kind of electroluminescent diode, compared with the traditional UV mercury lamp, it is more environmentally friendly, efficient and low energy consumption.

     The characteristics of UVLED.

     Single wavelength, high luminous efficiency, low energy consumption

     UVLED can convert electrical energy directly to UV light, and a single band ultraviolet light, light energy is highly concentrated in specific UV band, is now on the market mature application is 365nm, 385nm, 395nm, 405nm the band. However, the emission spectrum of the traditional UV mercury lamp is very wide, and the ultraviolet spectrum section, which can effectively cure, is only a part of it. At the same time, the photoelectric conversion efficiency is low and the energy consumption is large.

No infrared and ozone

     The traditional mercury lamp can produce infrared rays and emit a lot of heat, which is easy to cause damage to the heat sensitive substrate. The UVLED is a cold light source, can effectively avoid the substrate due to overheating and shrinkage deformation, the adaptability of the material more widely. At the same time for UV curing of UVLED is usually a long wavelength ultraviolet light, so in the curing process will not produce ozone, can maintain a good working environment, relative to the traditional mercury lamp safer, more environmentally friendly.

Electronic control

     The UVLED does not need to be preheated as a mercury lamp, and does not need to maintain the lamp life and efficiency. UVLED can instantly open (off) the light, the output energy can be set freely, and can automatically adjust with the machine speed, very energy saving, simple and convenient control.

Long service life and low maintenance cost

     LEDUV lamp life of up to 10 thousand -5 hours or more, is more than 10 times the traditional mercury lamp, and the light attenuation is very slow, the service life is not affected by the number of switches. At the same time, the LED light source has no mercury, no lampshade and other accessories, so it is not necessary to maintain and reduce the maintenance cost.

High flexibility, small system size

     LED light source can be divided into point light source, line light source and surface light source. The light source device has the advantages of small size, compact irradiation device and relevant supporting device, no need of larger mechanical installation space and pipeline construction. This feature makes it possible to adapt to all types of production processes, production processes are more efficient.

     2011-2016 UVLED and traditional UV mercury lamp equipment sales comparison

     UVLED and market prospects

     According to TechNavio research, UVLED market has maintained a very rapid growth in the past seven or eight years, from $20 million in 2008 to $90 million in 2014, a compound annual growth rate of up to 28.5%. 2016 due to the introduction of UV LED products, such as UV curing, sterilization and purification of the market, the estimated output value of $166 million, of which LED applications in the light curing market output value will reach $81 million. By 2020, the global UVLED technology market compound annual growth rate will reach 39%.

     2015, UV curing market accounted for 48.14% of the UVLED technology market.  The demand for UVLED curing equipment in the printing industry is increasing, and the flux density of UVLED chip has been improved greatly, which makes UV curing occupy a large part of the UVLED technology market. At the same time, the printing industry has developed into a large user of LED curing equipment. The UVLED technology has made great success in the field of inkjet, and promoted the application of UVLED technology in the whole printing industry.

     UVLED technology in the Asian market

     TechNavio predicts that the future of the Asia Pacific region, the fastest growing market for UVLED technology, UVLED technology in the Asia Pacific composite annual growth rate will reach 39.31%. Mainly due to the region's large demand for UV curing equipment and technology. China and India are emerging markets, which are encouraging UVLED manufacturers to increase production of UVLED, thanks to the government's efforts to promote energy-saving light sources and support industrial, medical and scientific sectors. LED light curing application mainly concentrates on the wood, and UV ink in three major areas, in the next few years will have a greater increase.      

     UVLED technology in the North American market

     UVLED technology accounts for 26.8% of the North American market share. TechNavio predicts that the North American UVLED technology market will grow from $34 million 330 thousand in 2015 to $179 million 60 thousand in 2020. Due to the rapid growth of the market, the North American graphic arts industry is increasingly using UV curing equipment and technology. Other UVLED light curing applications involving the health care industry, communications equipment industry, automotive industry, building materials industry, etc..

     UVLED resin

     Since UVLED is a single band of UV light source, the absorption spectrum of the initiator needs to match with the LED emission spectrum, the current market for the development of LED light source is not much, can be more mass production of the lack of. Therefore, the matching of initiator has been a difficult problem in LED light curing, and the currently used photoinitiator has TPO, TPO-L, ITX, DETX, BAPO, etc.. These initiators in 365nm, 385nm, 395nm, 405nm band and no very strong absorption peak, so the efficiency is not high. At the same time, compared with the traditional mercury lamp, the power is low, the radiation energy is not high, especially the ink color system, if the printing speed is too fast, easy to cause the ink curing is not complete

     In view of the problem of two aspects, such as the matching degree of the initiator and the power of the device, the light curing resin used for LED curing must have very high reactivity, so as to avoid the problem of bad curing. At present, the choice of UVLED curing resin market is very small, mainly due to the reaction activity and stability of these two issues.

Equilibrium of curing rate, surface oxygen resistance and storage stability

     Curing speed, resistance to surface oxygen resistance and storage stability, UV curing technology is very important in three aspects, relatively easy to achieve alone, but if the three have to take into account the difficulty is very large. Runao chemical researchers by experiments, using innovative methods are changed to the structure of the resin, and the auxiliary means, especially the development of UVLED resin with three different application system, to achieve the perfect curing speed, anti oxygen inhibition and storage stability of the balance of the three, which is to solve practical problems.

     Wood and plastic coatings

     FSP8370 is a four functional, specially modified polyester acrylate, specially developed for use in LED wood and plastic coatings. The resin has low energy curing speed, high conversion rate, high hardness, excellent wear resistance and water resistance. During the experiment, the light intensity is only 200mw/cm - 395nm point light source 10 seconds to dry. FSP8370 not only has prominent reactivity, but also has excellent storage stability. In the formulation of the initiator, the viscosity is not changed, and the thermal stability is excellent in 60 DEG C oven for 2 weeks.

UV direction

     FSP8376 is a two functional, specially modified polyurethane acrylate, specially developed for use in UVLED adhesive systems. The resin has the advantages of fast curing speed, low shrinkage, excellent cohesion and water resistance, high bonding strength to the plastic substrate, and the elongation at 130%.

Ink direction

     FSP8374 is a two functional, specially modified polyester acrylate, specially developed for use in UVLED ink systems. The resin curing speed, good flexibility, excellent pigment wetting, good flexibility, plastic, metal, glass have good adhesion, suitable for a variety of substrates. Good printability also makes it suitable for offset printing and screen printing process.

     The application of UVLED in the UV curing of

     UV inkjet

     At present, the market for UVLED curing technology is highly concerned, the most innovative inkjet field, while the advantages of UVLED curing just to meet the needs of this field.

     UVLED inkjet advantages: energy saving, high efficiency, high resolution, suitable for a variety of substrates. Applications: industrial or interior printing, inkjet printing, labeling and packaging printing.

UV offset

     Compared with ordinary UV printing, LEDUV offset printing, in the entire printing process, more energy saving and environmental protection, long life, can reduce energy consumption up to 70~80%, and the substrate has a superior adaptability.

PCB industry

     Components (capacitors, inductors, various plug-ins, screws, chips, etc.) fixed.

     Moisture proof potting and core circuit, chip protection.

     Circuit board type (angle) coating.

     Ground wire, wire, coil fixing.

     Wave soldering mask.

     Wood industry

     Compared with the traditional painting method, UVLED does not have an impact on the rate of substrate moisture, and from a closed bottom, primer, primer, paint the full realization of construction technology of UVLED fast curing, drying and curing time of eliminating the traditional wood finish bottom, long and low solid content and multi spraying construction procedures, to achieve full mechanization and the flow process, has a great role in promoting the improvement of plant capacity.

UV adhesive

     The use of UVLED curing glue has many advantages, such as low heat release, lower energy requirements, saving curing time and location, improve productivity, easier to automate. Therefore, it is widely used in the field of microelectronics and medical devices, and plays a role of adhesion, fixation and protection.

UV Nail Polish

     The use of low power LED lamp curing, the use of low heat release process, UV a good curing effect of oil, can be maintained for a long time as bright as new.   

     UV paints

     LED advantages: cold light source, less pollution, fast curing, low energy consumption, excellent film forming properties.

     Applications: mobile phone, automotive coatings, optical lens, plastic coating, optical fiber coating.