Fluorescent ink type of use is quite important for packaging anti-counterfeiting effect is good or bad, if choose not accurate or poor, can result in anti-counterfeit effect is not obvious or don’t have any security requirements, such as the theory according to the color of light color and light absorption principle, longer wavelengths in the color of light absorption wavelength. The following fluorescent ink in the actual product structure of the specific analysis.
If we are in the full version of the golden color printing on the coating of colorless fluorescent blue ink, fluorescent first blue ink layer under the uv lamp, blue (B) color, then coated with the bottom end of the golden (Y) color mixing, from color additive method in theory analysis, the mixture of yellow and blue light appear white, or yellow, and blue light mutually complementary color, that is to say, anti-counterfeit effect not beautiful or in some cases, don’t see any security role. According to the light base absorption theory, this is because the long-wavelength yellow light in the spectrum absorbs part of the short-wavelength blue light, so the fluorescence blue cannot be seen as the color it should be. However, the effect of fluorescent red is very good under the condition of publication and so on, and the effect under the standard light source irradiation.
From this we can get a conclusion, in the selection of fluorescent anti-counterfeit ink – must be careful, the general printing system has produced its complementary color light of the existence of ink or than the selected fluorescent ink color light wavelength longer than the existence of the fluorescent ink, the fluorescent ink had better not use or use after a certain anti-counterfeit effect. Therefore, in the production process of fluorescent anti-counterfeiting ink used in the pharmaceutical packaging industry, the selection of fluorescent ink for a variety of different printing substrate coating materials in the printing system is particularly important. In addition, the use of fluorescent ink for the printing process requirements are relatively strict, due to the particularity of its ink system, generally in the use of the process we should pay attention to consider the following factors:
Because of the drug packaging printing process is commonly used in gravure printing, so the choice of solvent in gravure printing is very important. Solvent is an important component of gravure printing ink, with solubility and volatility, the volatile speed is the key factor to determine the volatile ink drying speed and printing quality. The solvent volatilization speed is slow, the reproducibility of the printing image is better, but if the volatilization speed is too slow, in the print is not completely volatile, fluorescence ink layer is prone to adhesion, resulting in fuzzy anti-counterfeiting image, dirty layout, affect the anti-counterfeiting effect and the overall appearance of the product; On the other hand, if the ink solvent volatilization in the process of printing speed too fast, will produce the phenomenon such as inky white, sticky roller, latent inked back glue layer of the problems, and cause the dirty on the back of packaging materials, can clearly see the bright spots in ultraviolet light F, make consumers produce unsanitary intuition, serious when may affect the next coating and composite process.
Due to the printing equipment of each manufacturer, the operating environment is different, such as the speed of the printing machine, the structure of the drying system, the characteristics of the printing material, indoor temperature and humidity, etc., must be considered, so for the use of solvents in the printing process to consider all factors. Usually is to compare the link material resin dissolution parameters, combined with the above requirements, choose two or three different boiling point of the solvent with the use, can achieve the expected integrity of the anti-counterfeiting effect of the pattern.
(2) in fluorescent ink anti-counterfeit printing layout – a proportion are small and little fluorescent ink can produce a large number of security products, so in the production of fluorescent ink products, should be in accordance with the order as far as possible the task book: indicate the number of reasonably calculate the amount of ink, strive for one-time use up, don’t left a lot of unnecessary waste. General fluorescent ink products cannot repeat use for a long time, it is easy to play dirty, unnecessary pages not clean problem, 2 it is through long-term fluorescent pigments diluted solvent wash ink system, make the fluorescent anti-counterfeit effect is greatly reduced, even under ultraviolet light patterns or text, it outshines also cannot achieve the expected anti-counterfeiting effect.