Pearlescent Anti-Counterfeiting ink

Pearlescent anti-counterfeiting ink is one of the three major optical interference inks. It can be printed on both paper and plastic materials. Some high-end cigarette and wine packaging often use this special ink to print, thereby increasing the decoration of the packaging and improving the grade of the product. Its price Low and excellent endurance, can prevent the copying of scanners, electrical extensions and color copiers, so it has been widely valued. However, its technology continues to innovate and develop, which is showing its brilliant prospects.

      The printing adaptability and transferability of pearl anti-counterfeiting ink has its own characteristics. The material of the anilox roller has a decisive influence on the transferability of the flexographic ink. The ceramic anilox roller has an excellent effect for the pearl flexo E brush due to its special ink hole shape and excellent performance of absorbing and releasing ink. Pearlescent flexographic printing requires the fineness of pearlescent ink to match the number of lines of the anilox roller. The particle size of the pearlescent ink is larger than that of the traditional ink. Therefore, in order to ensure the quality of the printing station, certain printing conditions must be adjusted, such as reducing the number of anilox roller lines to match the transfer of larger particles of ink, which also makes the ink layer thicker. Adjust the drying temperature and pay attention to the smoothness of the paper. The pearlescent effect is determined by the amount of ink transferred to the substrate. The thicker the ink layer, the more obvious the pearlescent luster. For this reason, it is recommended to use an anilox roller with an inking hole as deep as 50um. According to the standard sample of the printed product, the excellent printing effect can be obtained by adjusting the printing speed. During printing, the ink can maintain a short leveling after being transferred to the substrate, so that the pigment crystals can maintain an excellent horizontal arrangement with the surface of the substrate. Pearlescent pigments, color changing pigments, fluorescent pigments

　 The cross-section of the pearlescent anti-counterfeiting ink pigment has a physical structure similar to pearls: the core is mica with low optical refractive index, and the outer layer is wrapped with metal oxides with high refractive index, such as titanium dioxide or iron oxide. In ideal applications, the pearlescent pigments are evenly dispersed in the coating and form a multi-layer distribution parallel to the surface of the carrier. The incident light will exhibit a pearlescent effect through multiple reflections and interference. Compared with traditional optical absorption type organic and inorganic pigments and optical reflection type metal pigments, the color forming principle of pearlescent pigments is completely different. By controlling the type of metal oxide on the mica wafer and the thickness of the metal oxide layer, different colors can be produced. The reflected light varies according to the thickness of the coated titanium dioxide. 40~60nm is silver, 60~80nm is yellow, 80~100nm is red, 100~120nm is blue, and 120~160nm is green. Different flicker effects can be produced by controlling the particle diameter of the mica wafer, so its effect is unique. In general, only monoclinic muscovite with a particle size of 10~100μM is suitable for manufacturing pearlescent pigments. The larger the particle, the higher the gloss, and the weaker the hiding power of the background color; on the contrary, the smaller the particle, The stronger the hiding power of the background color, the lower the gloss. With the increase of the number of layers, the pearlescent effect is enhanced and the chromatogram becomes wider. According to the number of layers and the layer materials, there are mainly three types: silver-white type, rainbow type and colored type.

       Silver-white is a commonly used variety, composed of anatase or rutile titanium dioxide coated mica flakes. It exhibits a variety of silver-white lusters ranging from delicate and soft to sparkling. Its characteristic is that the ink layer is thin and basically does not change color. Due to the narrow viewing angle, the color will be lost at a certain angle. Pearlescent pigments, color changing pigments, fluorescent pigments

      The overall ink layer of the rainbow interference color series is thicker. The material composition is the same as above, except that the titanium dioxide layer is thicker and uniform, which causes the reflected light to interfere selectively. At a specific viewing angle, some specific colors of light are highlighted, while their complementary colors disappear. Therefore, this series of products has the characteristic of "discoloration". By changing the geometric thickness of each envelope, its optical thickness will change accordingly, and the effect of interference colors such as yellow, red, purple, blue, and green can be obtained.

     The coloring series has many color systems, and its characteristic is that it basically does not change color, and will lose color when the deflection angle is large. Gold series: It is composed of titanium oxide and titanium dioxide composite coated with mica. Different products have golden luster with multiple hues. Compared with lead gold powder, it has good transparency, soft color and strong three-dimensional effect

     The silver-white type is a single-layer coating, the rainbow type is a multi-layer coating on the substrate, and the colored type is based on the silver-white and rainbow-type pearlescent pigments and then a colored pigment or dye coating is added.

Whether the arrangement of the colored pigments in the pearlescent anti-counterfeiting oil layer is parallel to the substrate determines whether the pearlescent effect is good or not. The main factors that affect the pearlescent effect of printed matter are: the nature of the ink, the transfer method of the ink, the printing process and the type of substrate. The flatness and smoothness of the printing material has a vital influence on the arrangement of the pigments. The better the flatness of the substrate, the more conducive to the formation of the mirror surface, so that the incident light can be refracted on the level produced by these optical refractions, thereby exhibiting an excellent pearlescent color effect. On the contrary, if the colored particles are disorderly and cause the incident light to be diffusely reflected, it is conceivable that the pearlescent effect will be weakened and it is difficult to achieve the beautifying and bright effect of pearlescent. Of course, for large-diameter pearlescent inks, the glitter effect does not only depend on the smoothness of the substrate. Pearlescent pigments, color changing pigments, fluorescent pigments

     Generally speaking, pearlescent anti-counterfeiting ink pigments are used to express the gloss effect and have a lower proportion of color. Therefore, it is obviously lighter in color than OVI ink, and it is obvious from the color change effect that one is heavy and the other is light. You can make many comparisons to experience it. The pearlescent anti-counterfeiting ink needs to be arranged in an orderly manner to make the printed matter achieve satisfactory pearlescent effect. Screen printing is not conducive to the orderly arrangement of pigments. Relatively speaking, pearlescent anti-counterfeiting inks are more suitable for printing on solid color blocks.