UV phosphor products introduce how to use anti-counterfeiting inks

An ink that emits visible light when exposed to light. The light referred to here is visible and invisible light such as ultraviolet light, infrared light, and sunlight.

a. Ultraviolet fluorescent ink: It emits visible light (400-800nm) ink under ultraviolet light (200-400nm). Pass

Frequently referred to as short-wave UV excitation of visible fluorescent anti-counterfeiting printing ink, excitation wavelength is 254nm, long-wave ultraviolet excitation excitation fluorescence

Anti-counterfeiting printing ink with an excitation wavelength of 365 nm.

b. Daylight-excited color-changing ink: It can emit anti-counterfeiting printing ink with visible light of 400-800nm under the illumination of sunlight. This ink

From the application point of view, it is discolored due to the action of sunlight, and is substantially discolored by ultraviolet radiation.

c. Infrared anti-counterfeiting ink: an ink made by matching infrared rays (700-1500nm) with different absorption characteristics, and can pass through

The instrument detects or identifies its mark. A pair of substances having different absorption characteristics for infrared rays are added to the ink. Application

The product printed by infrared ink has no reaction under ordinary light, and under infrared light detection, the corresponding signal can be observed.

Or graphic.

The use of fluorescent ink types is very important for the anti-counterfeiting effect of the packaging. If the selection is not accurate or not good, the anti-counterfeiting effect may not be obvious or may not be able to achieve any anti-counterfeiting requirements, such as the color rendering theory according to color light. As well as the principle of light absorption, medium and long wavelength color light absorbs short wavelengths. The following is an analysis of the specific conditions of fluorescent inks in the actual product structure.

If we print a colorless fluorescent blue ink on a full-stamp golden coating, first the fluorescent blue ink layer will appear blue (b) in the ultraviolet light, and then the golden (y) light at the bottom of the undercoat. Mixing, theoretically analyzing from the color-added color method, after the yellow light and the blue light are mixed, the white light is present, that is, the yellow light and the blue light are mutually complementary colors, that is, the anti-counterfeiting effect is not good or in some cases, the color is not seen at all. To any anti-counterfeiting effect. From the theory of absorption at the bottom of the light, this is because the yellow light of the medium-long wave in the spectrum absorbs part of the blue short-wavelength light, so that the color that the fluorescent blue should be present cannot be seen. Fluorescent red works well in the case of journals and so on, and it is effective under the illumination of standard light sources.

From this we can draw a knot, when choosing a fluorescent anti-counterfeiting ink - be careful, in the general printing system, there is an ink that produces its complementary light or there is an ink longer than the wavelength of the selected fluorescent ink. The fluorescent ink is preferably not used or does not have a certain anti-counterfeiting effect after use. Therefore, in the production process of fluorescent anti-counterfeiting inks 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 inks is also stricter on the printing process. Due to the particularity of the ink system, we should pay attention to the following influencing factors during the use:

1 Because gravure printing is commonly used in pharmaceutical packaging printing processes, the choice of solvent in gravure printing is very important. Solvent is an important component of gravure ink, has solubility and volatility, and its volatilization speed is an important factor determining the drying speed and printing quality of volatilized ink. The solvent volatilization rate is slow, and the reproducibility of the printed image is better. However, if the volatilization speed is too slow and the volatilization is not completely evaporated on the printed matter, the fluorescent ink layer is likely to be stuck, resulting in an anti-counterfeit image blurring and the layout being dirty. Affect 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, it will produce whitening, sticky rolls, etc., and lurk the hidden trouble of the ink layer to stick back, resulting in the back of the packaging material. Dirty, in the UV light, you can clearly see the bright spots, so that consumers can produce unsanitary intuition, which may affect the coating and compounding process of the next channel. Due to the printing equipment of various manufacturers, the operating environment is different, such as the speed of the printing press, the structure of the drying system, the characteristics of the printing material, the temperature and humidity of the room, etc., so the solvent is printed during the process of printing. Use to consider all factors. Usually, the dissolution parameters of the binder resin are compared. In combination with the above requirements, two or three solvents with different boiling points are used together to achieve the desired complete anti-counterfeiting effect pattern.

2 Fluorescent inks are very small in the anti-counterfeiting printing layout. Few fluorescent inks can produce a large number of anti-counterfeiting products. Therefore, when producing fluorescent ink products, they should be as far as possible according to the order task book: Calculate the amount of ink, and strive to use it all at once, and don't leave too much to cause unnecessary waste. Generally, fluorescent ink products cannot be reused many times for a long time. First, it is easy to get dirty, which brings unnecessary layout problems. Second, after long-term solvent washing, the fluorescent pigments of the ink system are diluted, so that the fluorescent anti-counterfeiting effect is greatly reduced, even in the ultraviolet lamp. The pattern or text under the illumination is also dull and does not achieve the expected anti-counterfeiting effect.