Sun chemical produces UV LED ink, mainly inkjet ink and screen printing ink. In general printing applications, the printing effect is not perfect.
The company is very interested in UV LED curing technology, but from an ink manufacturer's point of view, the technology still has some problems, one of which is how to get UV energy.
LED light source is monochromatic light, which usually works in the range of 390 ~ 400 nm. This is the beginning of visible energy. A typical mercury vapor lamp produces an inefficient amount of ultraviolet energy. Only about 20 percent of the energy produces ultraviolet light, while 20 percent is visible energy and 40 percent is heat. The LED will transfer all the power to the desired part. But a standard mercury vapor lamp can plug in a lot of energy and emit more energy.
The standard uv bulb emits a spectrum of 200 to 400 nm, and has some unwanted radiant energy, but it can be used. Let different photoinitiators do different things, including what they do and what they want them to do. Ink pigments also transfer energy, so some pigments solidify better than others.
Besides ink, there's varnish. Varnish is usually used to achieve some kind of surface effect. The type of energy produced by UV LED lights does not solidify the surface well. It is difficult to use UV LED lamp to obtain a good curing UV varnish film. Another problem is that photoinitiators, which produce solidified surfaces, do not absorb energy well.
Still, the new technology is likely to be used in other areas in the future, and will certainly be improved in some places and more widely accepted.
As for curing speed, some people say that the printing speed of UV LED will be limited. The power of UV LED is relatively low, but many modules can be installed to improve power. When adding power, there should be equipment to cool the UV LED. Therefore, we need to weigh the total cost, is it really meaningful to increase the UV LED device?
UV curing ink compared to standard UV curing ink, UV LED curing ink will be more expensive. More light initiators are added to the ink, which is usually more expensive.