Identification of UV ink

Observe ink color
When purchasing UV ink, it is necessary to "check the color and appearance". UV ink is sensitive to ultraviolet light. If the applied UV ink continues to be exposed to ultraviolet light (such as sunlight and fluorescent lamps), the UV ink will continue to react and turn yellow, which is a defect of the UV ink itself. For conventional UV inks, it is currently impossible to fundamentally improve, but the degree of yellowing of UV inks from different suppliers varies, unless specific non yellowing or ultra white UV inks are used.
The main reason for the discoloration of UV ink after polishing is due to issues with the ink. There are some pigments in ink, such as Brilliant Blue, which is a blue acidic lake pigment. It is an insoluble pigment in water formed by the organic dye triphenylmethane attached to bulk pigments such as aluminum hydroxide. It has a low price and bright color, but its light resistance, solvent resistance, and alkali resistance are poor. When it encounters solvents such as alcohols or alkali, the red phase is easily dissolved, weakened, or disappeared. These pigments are feasible for use in book and magazine inks (without surface gloss treatment after printing), but they are very dangerous if used in color box inks because most color boxes have post-processing treatment. The detection method is to drop a drop of base oil and ink on the surface of the ink, and after 1 hour, check whether the ink changes color, which is very obvious.
For printed paper, if the ink changes color, forced ink drying can be used, such as drying or leaving for a longer period of time, or neutral base oil, solvent-free UV ink, solvent-free book UV oil can be used to solve the problem
Ink and other methods can be used to reduce the tendency of ink discoloration.
Distinguish the smell of ink
When purchasing ink, we also need to "distinguish the odor" to evaluate the odor of UV ink. There are two indicators: one is the odor during the construction process, which mainly comes from residual solvents in UV ink. Under normal circumstances, the residual solvent content is less than 2%, and in special circumstances, such as cigarette packaging UV ink, it is required to be less than 0.5%, but due to soaring oil prices. Many suppliers add a large amount of solvents, such as alcohol and toluene, to reduce the cost of UV ink, with the highest reaching up to 25%. This is detrimental to the long-term development and environmental protection of UV ink.
Another indicator for evaluating the odor of UV ink is the residual odor of UV ink after construction, which cannot disappear even after a long period of time. The main source is improper selection of UV ink materials and the use of some odorous but inexpensive chemicals. It is difficult to fundamentally improve this, mainly due to cost and the selection of suitable materials.
More importantly, the price of purchasing UV ink should be evaluated based on the brand and cost-effectiveness of the ink. Many ink multi-level suppliers have mixed quality, and without comparison, it is possible to buy products with higher prices or ink products that are not authentic. When purchasing UV ink, we also need to consider transportation costs, so choosing a reasonably priced and trustworthy ink supplier is very important. I recommend my consumables website, which is the largest online store for printing consumables in China. It is very convenient to purchase any printing ink and printing materials on the website. With just a few clicks of the mouse, you can buy the ink you want. The price of the ink sold is as low as the factory price, making it the best platform for printing companies and printing factories to purchase ink.