UV curable, 3D printing, UV LED curing, UV flexo ink, UV inkjet, Water-based UV, Photoresist, Matte paint, Medical adhesive, Photoinitiator, Bio-based materials, Hybrid curing technology
In this article, we will review the highlights of radiation curing industry in 2020 and also discuss the field and applications deserve our attention in 2021 in the industry.
1. 3D printing (additive manufacturing)
After experiencing an overheating period and a trough period, 3D printing has now entered a rising period, and the application of 3D printing has become more and more mature and widespread. It’s widely used in traditional mold applications, and the cost is decreasing.
3D printing continues to strengthen in medical applications, and one of its typical applications is dental materials. According to incomplete statistics, the annual output of dental mold materials in China has exceeded 10,000 tons, and is growing steadily.
Compared with traditional subtractive and equivalent material manufacturing, 3D printing can not only produce objects with more complex shapes, but also use the diversification of the material properties which makes it possible for many previously impossible applications. Its printing speed is also continuously improving.
2. UV LED curing
UV LED curing has replaced the traditional mercury lamp curing in many applications, such as adhesives and inks. It can not only save the energy , but also be switched on and off at any time, without ozone generation or mercury pollution, etc., so it’s widely used. However there are still many problems to be solved, such as surface curing, UVB and UVC band curing, photoinitiator yellowing, and supporting high-activity UV resins.
3. UV flexo ink
UV has been used in silk screen and offset printing inks for a long time and is very popular.
The flexo ink printing market is huge, mainly used for packaging printing of some daily products. It is still mainly based on traditional water-based, and alcohol solvents are also used. With the strengthening of VOC control, many large printing companies have gradually switched to UV, and this speed will also accelerate.
4. UV inkjet
Inkjet printing does not require complicated plate making process, and can be printed on site (such as home TV curtain wall printing), which makes it rapidly popularized in customized applications and the market of decoration materials.
In traditional inkjet printing, ink solvents account for more than 95%, and all these solvents will enter the atmosphere as VOCs, causing great pollution. Therefore, the application of UV inkjet in inkjet and outdoor light boxes has become more and more mainstream.
5. Water-based UV
Although UV curing has many advantages, its viscosity control is always a big challenge. That’s because the viscosity of the UV resin, which contributes the main performance, is usually very high. There are also many high-solid and low-viscosity products, but the selection of raw materials is relatively limited and performance is still subject to many restrictions. Water-based UV can solve the problem, because water-based UV systems can add any proportion of water to adjust the viscosity.
Of course, there are still many technical and technological problems in the water-based UV system, the main of which is the balance between performance and process. Fortunately the current progress is very encouraging. The control of solvent-based products in the 3C field will also greatly promote the development of water-based UV technology. Many major international manufacturers are already fully turning to water-based UV applications, which is another typical representative of technology advancement from the terminal.
Photolithography is a necessary process for manufacturing high-precision chips, and photoresist is one of the key raw materials. For the highest precision semiconductor photoresist used in chip manufacturing, it is completely dependent on imports.
The application of photoresist technology requires close cooperation between upstream and downstream enterprises, with long test cycle, high test risk, high cost, and extremely high requirements for basic chemicals.
7. Matte paint
With the change of people's aesthetic orientation, we have gradually transitioned from our first preference for shiny and golden high-gloss paint to semi-gloss and now matte decoration. From furniture to flooring, including all kinds of home decoration materials, they are gradually shifting to the "low-key, luxurious and connotative" decorative style of matte.
The first important feature of light-curing coatings is compactness and high gloss because of their high crosslinking density. Therefore, it becomes an important trend in the development of photocurable coatings, and also a difficult point, to achieve low gloss while maintaining the inherent physical and mechanical properties of photocuring.
8. Medical adhesive
Compared with traditional adhesives, UV products are more and more widely used in the medical industry with a faster curing speed and higher strength. Dental filling materials are one of the oldest applications of light curing in the medical industry. In addition used in the manufacture of medical equipment and consumables, the development of medical UV adhesives for wound repair is also very rapid. Although it still takes time to be fully clinically applied, once it is widely used in clinical practice, it can greatly improve the effect and efficiency of wound repair.
9. Self-healing materials
Light-curing and self-healing materials have been advancing in parallel at the same time, and the intersection of these two technical lines makes the manufacture of self-healing materials easier and more convenient.
In the process of promotion and popularization of UV LED curing technology, the current LED curing wavelength is still concentrated in the UVA band due to the equipment band and cost. There are not many options for photoinitiators in this band, and most of them have color or yellowing problems. Therefore, the introduction of photoinitiators that can absorb well at long wavelengths without yellowing has always been a rigid demand in the market. The development of UV LED equipment cooperating with photoinitiators toward UVB and UVA also greatly affects the development of photoinitiators.
11. Bio-based materials
The new material industry is based on petroleum, a downstream product of petroleum, and petroleum is a non-renewable resource. Therefore, looking for alternative renewable resources is an important topic that materials scientists have been paying attention to.
Large companies in the light curing industry are constantly paying attention to and launching bio-based light curing materials. Neither the needs of customers nor the promotion of the government, gives enough attention to bio-based materials at present. It still takes time.
11. Hybrid curing technology
Any single curing technology will have its own advantages and disadvantages. The combined use of different curing technologies can combine the advantages of processes and materials in different curing technologies.
The aforementioned water-based UV is a hybrid curing technology. The combination of UV and powder UV powder coating technology has shown great advantages in applications, such as MDF.
The combination of LED and mercury lamp is a good way to cooperate with curing equipment that can effectively solve the problem of photoinitiators.
UV-curable three-proof glue is a combination of UV and moisture curing, and is quickly replacing the traditional solvent-based three-proof glue system. And with the increasing demand for waterproof and moisture-proof electronic equipment and the improvement of standards, UV three-proof glue will continue to heat up.
The combination of UV excimer curing technology and traditional mercury lamp curing technology perfectly combines the two curing characteristics to obtain a special skin-feel surface and a coating with excellent physical properties.
Electron beam curing has a long history of development in Europe and America, and its application is also quite extensive, covering packaging and decorative materials. The combination of electron beam and light curing will better promote and develop electron beam curing technology, which may bring a revolutionary change in the decorative materials industry.