Anti-counterfeiting technology is a cross-cutting discipline that involves optics, chemistry, physics, electromagnetism, computer technology, spectroscopy, printing technology, packaging technology and many other fields. Ink anti-counterfeiting technology is a kind of anti-counterfeiting technology widely used in the pharmaceutical packaging industry. This kind of anti-counterfeiting technology is mainly used to add special materials in the ordinary ink connecting material, through a special process to become a special printing ink technology. This type of anti-counterfeiting technology is characterized by: simple implementation, low cost, good concealment, vivid colors, and easy inspection. At present, there are mainly anti-counterfeiting ink UV-activated fluorescent anti-counterfeit inks, magnetic anti-counterfeit inks, thermal anti-counterfeiting inks, sunlight anti-counterfeiting anti-counterfeiting inks, optical variable security inks, pressure-sensitive anti-counterfeit inks, infrared anti-counterfeit inks, anti-falsification anti-counterfeit inks, anti-counterfeit ink, etc. .
Ink printing anti-counterfeiting is an important part of the pharmaceutical packaging anti-counterfeiting technology. Experiments show that fluorescent anti-counterfeit inks with fluorescent pigments are well-tolerant to water, acid, and alcohol, and are now widely used in pharmaceutical packaging, especially in blister packaging. It is also commonly used in other pharmaceutical packaging such as pharmaceutical flexible packaging and pharmaceutical labels. It can be said that the fluorescent anti-counterfeiting ink is a kind of anti-counterfeiting ink which is most widely used in the anti-counterfeiting of pharmaceutical packaging inks.
Fluorescent inks are made by adding the corresponding visible fluorescent compound to the ink. Its anti-counterfeit feature is: Under the action of visible light and ultraviolet rays, printed matter can emit glittering fluorescence. Different formulations can give different fluorescent inks. If ultraviolet ray excited visible fluorescent compounds (such as tristyryl derivatives, stilbene derivatives, tetrastyryl derivatives, etc.) are added to the ink to obtain ultraviolet fluorescent ink, red, yellow and green light may be emitted under the irradiation of ultraviolet rays. Blue and other visible light. Infrared fluorescent ink can be obtained by adding a visible fluorescent compound having infrared excitation in the ink, and green visible light can be emitted under the irradiation of the infrared lamp.
Fluorescent inks are invisible and visible.
1 Invisible fluorescent ink security: The material used is invisible fluorescent ink, the printing process is simple. The ink printed invisible patterns or text, under the irradiation of ultraviolet light, showing a clear and bright fluorescent pattern, colorful. The anti-counterfeiting detection is convenient, as long as there is a UV light source or a money detector.
Since the invisible fluorescent ink is invisible or colorless, it is invisible to the naked eye during printing, that is, it does not have any tracking marks for machine identification. Therefore, it is difficult to overprint, but this kind of anti-counterfeit concealment is better and the anti-counterfeiting strength is stronger. At present, most of the domestic pharmaceutical packaging uses this kind of invisible fluorescent ink.
2 tangible fluorescent ink anti-counterfeiting: the material used is tangible fluorescent ink, the printing process is simple, accurate registration, the printing effect is the same as ordinary ink printing effect, but under the irradiation of ultraviolet light, the printed material shows abnormal light, at this time, can be distinguished Ordinary ink.
The use of the fluorescent ink type is very important for the anti-counterfeiting effect of the packaging. If the selection is inaccurate or poor, the anti-counterfeiting effect may not be obvious or any anti-counterfeiting requirements may not be achieved at all, for example, according to color light color theory As well as the principle of light absorption, the medium wavelength light absorbs short wavelengths. Therefore, when choosing the fluorescence anti-counterfeiting ink, we must be cautious. When the general printing system has the ink that produces its complementary color light or there is ink with longer wavelength than the selected fluorescent ink, it is better not to use the fluorescent ink. After use can not reach a certain anti-counterfeiting effect. Therefore, in the production process of fluorescent anti-counterfeiting inks used in the pharmaceutical packaging industry, the selection of fluorescent inks for a variety of different printing primer materials in the printing system is particularly important.
In addition, the use of fluorescent ink for the printing process requirements are also more stringent, due to the particularity of its ink system, generally in the use of the process we must pay attention to consider the following factors:
1 Since gravure printing is commonly used in drug packaging and printing processes, the choice of solvent in gravure printing is very important. Solvent is an important component of gravure ink. It has solubility and volatility. Its volatilization rate is an important factor in determining the drying speed and printing quality of volatile ink. Solvent evaporation rate is slow, and the reproducibility of the printed image is better, but if the evaporation rate is too slow, it will not completely volatilize on the printed matter, the fluorescent ink layer is prone to adhesion, resulting in blurred security image, dirty layout, Affects the anti-counterfeiting effect and the overall appearance of the product; conversely, if the solvent in the ink volatilizes too quickly during the printing process, ink whitening, sticky rollers, etc. may occur, and potential problems with the back layer of the ink layer are hidden, resulting in the back of the packaging material. Dirty, under the UV light can clearly see the bright color spots, so that consumers have unsanitary intuition, when serious may affect the next coating and composite processes. Due to various manufacturers' printing equipment, the operating environment is different, such as the speed of the printing press, the structure of the drying system, the characteristics of the printing materials, the indoor temperature and humidity, etc. must be considered, so the use of solvents in the printing process Take all factors into consideration. Usually, the dissolution parameters of the binder resin are compared. In combination with the above requirements, two or three different boiling point solvents are used together to achieve the expected complete anti-counterfeit effect pattern.
2 The proportion of fluorescent ink in the security printing plate is generally very small. It can be said that very few fluorescent inks can produce a large number of anti-counterfeiting products. Therefore, when producing fluorescent ink products, they should try to follow the amount specified in the order book. Reasonably calculate the demand for ink, fight for a one-time use, or do not leave too much to cause unnecessary waste. General fluorescent ink products can not be repeatedly used for a long time, one is easy to get dirty, bring unnecessary layout unclean problem, the second is after long-term solvent flushing ink system fluorescent pigment dilute, making the fluorescent anti-counterfeiting effect is greatly reduced, even in the UV lamp Under the irradiation of the pattern or text is also dull, failing to achieve the desired anti-counterfeiting effect. It is also very important for the factory and the enterprise to consider economic benefits because fluorescent inks are expensive and more than ten times higher than ordinary ink prices.