Although UV radiation is harmful to human body, it is a natural enemy of bacteria and viruses, especially UVC band UV. As shown in Figure 4, it can kill bacteria and viruses in a short time.

UVCLED is widely used in hospitals, air conditioning systems, disinfection cabinets, water treatment equipment, drinking machines, sewage treatment plants, swimming pools, food and beverage processing and packaging equipment. In addition, in the most recent scenes from our daily life, there have been a lot of disinfection, sterilization applications, such as maternal and infant sterilization kits, toothbrush sterilizers, portable sterilizers and so on.

Ultraviolet B is in an awkward position and has little application at present. Recently, it has been heard that medical applications have begun to use UVB band. 293 nm UVB can produce vitamin D3 and inhibit metabolic bone diseases such as osteoporosis, especially in areas lacking sunshine. But because the market is so small, few people talk about U. VB.

UVA band is the mainstream of UV market because it can irradiate special glue to make the glue polymerize and curing.

How to solidify? I am a student of physics, organic chemistry is not my specialty, so I use what I know to give you science popularization! UV adhesive curing principle is that the photoinitiator (or photosensitizer) in UV curing material absorbs ultraviolet light and produces active radicals or cations, initiates monomer polymerization, cross-linking and branching chemical reactions, so that the binder from liquid to solid in a few seconds, because the photoinitiator only in the appropriate wavelength range So different wavelengths will correspond to different UV glue. What I know is that the UV glue with 365 nm wavelength photoinitiator is cheaper, but the UV LED with 365 nm wavelength is more expensive. After synthesizing the UV curing technology of 365 nm and 380 nm ~ 395 nm is not cost-effective. On the contrary, perhaps the future 365nm wavelength LED has a breakthrough in cost performance, and the mainstream curing technology will be 365nm.

Typical applications of UVA band are UV curing and UV inkjet printing. The typical wavelengths are 380nm~395nm and 365nm~370nm. UV adhesives are cured in the display, electronic medical and instrumentation industries; UV coatings are cured in building materials, furniture, household appliances, automobiles and other industries; UV ink curing in printing and packaging industries can see the traces of UVA. In the electronics industry, the PCB version of the exposure machine is the main wavelength of 365 nm, semiconductor chip moisture protection coating, wafer mask, etc., all need UV glue curing technology. In addition to these applications, in daily life, we can often see the shadow of UV, such as 365 nm wavelength mosquito killer lamp, this application is not possible in other bands; and UVA curing nail polishers, usually 365 nm and 390 nm bands, can make the nails coated with glue more gorgeous!