Factors needing attention in the use of the hottes

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Precautions for the use of fluorescent ink

the use of fluorescent ink types is very important for the quality of packaging anti-counterfeiting effect. If the selection is inaccurate or poor, it may lead to the anti-counterfeiting effect is not obvious or can not meet any anti-counterfeiting requirements at all. For example, according to the color theory of color light and the principle of light absorption, medium and long wavelength color light absorbs short wavelength. The specific situation of fluorescent ink in the actual product structure is analyzed below

if we print colorless fluorescent blue ink on the full-scale golden yellow coating, first the fluorescent blue ink layer shows blue (b) light under the illumination of UV lamp, and then it is mixed with the golden yellow (y) light at the bottom of the undercoat. According to the theory of color light addition, after the yellow light and blue light are mixed, it shows white light, that is, the yellow light and blue light are complementary to each other, In other words, the anti-counterfeiting effect is poor or in some cases, there is no anti-counterfeiting effect at all. From the light absorption theory, this is because the yellow light of the medium and long waves in the spectrum absorbs part of the blue short wavelength light, so we can't see the color that the fluorescent blue should present. Fluorescent red has a good effect in print and other cases, and it has a good effect under the irradiation of standard light source

from this, we can draw a conclusion that we must be careful when choosing fluorescent anti-counterfeiting ink. When there is an ink that produces its complementary color light in the general printing system or an ink with a longer color wave than the selected fluorescent ink, this kind of fluorescent ink is best not to be used or cannot achieve a certain anti-counterfeiting effect after use. 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 primer materials in the printing system is particularly important. In addition, the use of fluorescent ink has strict requirements for the printing process. Due to the particularity of its ink system, we should generally consider the following influencing factors in the use process:

① as gravure printing brushes are commonly used in the pharmaceutical packaging printing process, the selection of solvents in gravure printing is very important. The solvent volatilization speed is slow, which is good for the reproducibility of the printed image. However, if the volatilization speed is too slow and it is not completely volatilized on the printed matter, the fluorescent ink layer is easy to stick, resulting in blurred anti-counterfeiting images and dirty layout, which affects the anti-counterfeiting effect and the overall appearance of the product; On the contrary, if the solvent in the ink volatilizes too fast in the printing process, it will produce phenomena such as white ink and roller sticking, and the hidden trouble of ink layer back sticking will be hidden, causing the back of the packaging material to be dirty. In the UV light F, you can obviously see the bright colors and spots, which makes the consumer have an unsanitary intuition, and in serious cases, it may affect the next coating ldquo; The rapid growth of orders reflects the continuation of demand explosion and composite processes

since the printing equipment and operating environment of each manufacturer are different, such as the speed of the printing machine, the structure of the drying system, the characteristics of the printing materials, indoor temperature and humidity, etc., all factors must be considered, so the use of solvents in the printing process should be comprehensively considered. 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 expected complete anti-counterfeiting effect pattern

② in the anti-counterfeiting printing layout, the larger the load required to destroy the sample is, the smaller the proportion is. A small amount of fluorescent ink can produce a large number of anti-counterfeiting products. Therefore, when producing fluorescent ink products, we should try to reasonably calculate the amount of ink according to the amount indicated in the order specification, and strive to use it up at one time, so as not to leave too much to cause unnecessary waste. Generally, fluorescent ink products cannot be reused for many times for a long time. First, it is easy to get dirty, which leads to the problem of unnecessary unclean layout. Second, after long-term solvent washing, the fluorescent pigment of the ink system is diluted, which greatly reduces the fluorescent anti-counterfeiting effect. Even under the irradiation of UV lamp, the pattern or text appears dim, which cannot achieve the expected anti-counterfeiting effect

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