UV pad printing ink is different from other types of ink, UV ink is cured and dried rapidly under UV energy. When UV light penetrates the ink, the photosensitive molecules in the ink will react with the neighboring molecules, the whole process in seconds or milliseconds. It has the characteristics of friction resistance, acid and alkali resistance and no volatile matter.
Sublimation ink needs special processing in the use process, that is, after printing, it needs to be heated to make the substrate porous, so that when the dye contacts the heated substrate surface, the dye in the ink becomes gaseous, and then enters the substrate surface, which actually changes the surface color of the substrate. Once the substrate cools, the ink sticks to the substrate surface.
The most common application of sublimation ink is computer keyboard printing, as well as those with higher requirements for oil resistance and wear resistance, which can not be achieved by using two-component ink. In particular, because sublimation ink actually changes the surface color of substrate, it is difficult to match the substrate and ink color. Therefore, the color of substrate must be lighter than the color needed for final printing, because the color change of sublimation ink on the substrate surface with darker color is often less obvious.
Special pad printing inks include edible inks, silicone resin inks, lubricating inks, corrosion resistant inks, conductive inks and UV curing inks. The ability of these inks to quickly become sticky will determine whether the ink can be effectively transferred to the substrate surface. At the same time, in order to adjust the printability and performance of the ink, in addition to the addition of solvents and catalysts, there may be many auxiliaries, such as viscosity inking agent, antistatic agent, rheological agent, etc. However, the use of auxiliaries will have a great impact on the printing performance of ink, so we must be careful when using them.