How to distinguish UV ink

UV ink is a solvent-free, fast drying speed, good gloss, bright colors, water resistance, solvent resistance, good wear resistance ink. Uv ink refers to the use of different wavelengths and energy of ultraviolet light to make the ink connection material monomer polymerized into polymers, so that the ink into a film and dry ink. Now from the following two aspects to identify the quality of ink good or bad
China
.
1, observe the ink color
to purchase UV ink to "check the color." UV ink is sensitive to UV light, if the UV ink after construction continues to be exposed to ultraviolet light (such as sunlight and daylights), UV ink will continue to react and turn yellow, which is the UV ink itself defects. For conventional UV inks, it is not possible to fundamentally improve for the time being, but the degree of yellowing of UV inks from different suppliers is different unless specific non-yellowing or white UV inks are used.
for UV ink after lighting ink color change, the main reason is ink problems. Ink has some pigments, such as light blue, is a blue acidic pigment, is an organic dye tribenzene methane stain attached to the body pigments such as aluminum hydroxide, the formation of insoluble pigment pigments in water, low price, bright color, but its light resistance, solvent resistance and alkaline resistance, alcohol and other solvents or alkali, red easily dissolved, weakened or disappeared. These pigments, such as those used in book inks (the surface is no longer polished after printing), are feasible, but are very dangerous if used in color box inks, as most color boxes are post-processed. The detection method is to drop a drop of oil and ink on the surface of the ink, 1 hour later to see if the ink is changing color, very obvious.
For printed paper, if the ink changes color, you can use forced ink drying, such as drying or a little more time to solve, or the use of neutral base oil, solvent-free UV ink, solvent-free books UV ink and other methods to reduce ink color change tendency.
2, distinguish the taste of ink
When buying chinese ink, we also need to "debate taste" assessment of the smell of UV ink has two indicators, one is the smell during the construction process, the main source is the residual solvent in UV ink, normally, the residual amount of solvent is 2% Below, in special cases, such as cigarette packet UV ink requirements less than 0.5%, but in today's soaring oil prices, many suppliers in order to reduce the cost of UV ink, added a large number of solvents, such as alcohol and toluene, the highest can reach 25%, which is detrimental to the long-term development of UV ink and environmental protection.
Another indicator of the evaluation of UV ink odor is the residual odor of UV ink after construction, placed for a long time after the general still can not disappear, the main source is UV ink selection is improper, the use of some taste larger but inexpensive chemicals, which should be fundamentally improved there is a certain difficulty, mainly cost and selection of suitable materials.