Among the most popular types of special gloss prin

Types of special gloss printing for packaging (middle)

luminescence is a process in which an object converts absorbed energy into light radiation in some way. The phenomenon that luminaries emit light due to external effects is called "excitation" in optics. The difference between fluorescence and phosphorescence is that the excitation molecules fall from the excited state to the ground state through different ways, and the length of excitation to luminescence time is also different. Therefore, when the incident light source is cut off, the presence of phosphorescence can be seen, and the fluorescence will disappear soon. Luminescent substances need to be trusted institutions in the industry. There are two major categories: organic and inorganic phosphors: red (yttrium oxide), yellow green (zinc sulfide), blue (silver sulfide) and so on. The price is usually 2-3 times that of electronic mechanics experimental machines. This kind of phosphor is expensive and is mainly used to coat color kinescope. The inorganic phosphor with low price is rough, and the luminous crystal is damaged after grinding, which reduces the luminous brightness. The ink made of this phosphor has poor transparency, strong hiding power, and easy printing paste, but it has strong moisture resistance. Synthetic organophosphorous phosphor powder consists of two parts: carrier and excimer. Excimer can excite specific carrier to make materials that do not emit light or emit weak light. Different varieties of excimer can also change the wavelength and color of the original light. This organic phosphor powder has simple manufacturing process, low price, fine particles, small loss of luminous brightness after mechanical grinding, and the ink made of it has high transparency and small hiding power

before phosphorescence and fluorescent printing, two processes are usually used: one is to make phosphor powder into coating, produce phosphorescence and fluorescent paper, and then ink printing; The other is to make light powder into ink for direct printing. There are two ways to prepare ink: one is to add connecting materials and solvents to the light powder, and then make ink after ball milling; The other is directly synthesized into colorless and transparent phosphorescent liquid, which is naturally dried after printing or cured and dried by UV light. In particular, it should be pointed out that phosphorescent and fluorescent inks should be placed on the top layer of the print, that is, the last layer of the print, to prevent the general ink color from covering the phosphorescent color. Because phosphorescent color is printed on other inks, while black, dark purple and other colors will absorb phosphorescent light, reducing the luminous intensity; White and light colors can improve the luminous brightness. Therefore, try to use light and light tone or reduce the printing level

variable gloss printing

variable gloss printing refers to a printing process that uses special inks or materials to produce prints, which can produce gloss changes under the variable force of a certain energy. At present, it can be divided into two printing processes: thermochromic and photochromic

1. thermochromic printing process. This process uses some substances that can produce color change when heated, such as metal iodide, complex, double salt and liquid crystal materials, to make ink and form a color change layer on the print. Prints can change in color with temperature changes and external heating conditions. Thermochromic inks can be divided into Reversible Thermochromism and irreversible thermochromism. The former refers to that the color can be restored to its original state after being separated from the heat source, while the latter refers to that it cannot be restored to its original state after changing color. According to relevant information, the key to the production of thermochromic ink materials is to use microencapsulation technology to treat colorants and color changing substances, and then appropriately add connecting materials and fillers to make ink. The color changing ink prepared in this way can make the color change bright and sensitive, not affected by other reactive substances, and can improve its heat resistance, durability and washing resistance

2. Photochromic printing. Photochromic process printing uses photosensitive color changing materials, which are processed into ink by microcapsule technology, and then transferred to the printed matter through the printing machine to form a color change layer. Under the action of sunlight and light, the color of prints will change: from deep to shallow, or from shallow to deep; Or from colored to colorless, or from colorless to colored; Leaving the light source, it will return to its original state; Variable gloss printing has attracted people's attention because of its special properties and functions. In recent years, it has been popularized and applied in the field of packaging and decoration, especially in the field of packaging anti-counterfeiting. As long as people take a certain heat source or light source to contact the decoration printed with variable ink to verify the change of ink, we can immediately see the authenticity

metallic gloss printing

metallic gloss printing should be related to iron printing process. In the iron printing process, Haneda airport also used the particles generated by 80 tons of waste tires. It was found that the lower transparent ink was printed on the tinplate after plating, polishing and mirror treatment, and the printed products could produce a flashing, translucent and magnificent effect, which felt very high-end. Affected by this, due to the emergence of metal paperboard, electrochemical aluminum materials and vacuum aluminum plating technology, it has been introduced into the field of paper and plastic composite packaging. Metal paperboard is also known as aluminum foil paperboard. One of its production processes is to use calendering method to make metal aluminum into ultra-thin aluminum foil and then compound it with paperboard; The other is to compound the plastic film with paper after vacuum aluminizing. Generally speaking, the surface of metal paperboard is smooth, with mirror effect, no pores, and poor printability. Ink with strong adhesion should be used for printing. Encourage state-owned enterprises and private enterprises to promote each other and integrate the military and civilian. Moreover, the ink amount is also very important. A large amount of ink is not suitable for dry conjunctiva, which affects the transparency of prints and is easy to get dirty; The ink volume is small and does not cover the bottom. Practice has proved that using UV curing ink printing process can make the ink instantly dry, and the effect is better. Anodized hot stamping material is also another process of metallic gloss printing. Anodized aluminum, also known as metal powder foil heat transfer material, transfers the sprayed metal layer to the print by heating and pressing, so that the print produces a magnificent metallic luster. At present, most of the packaging has the requirement of ironing anodized aluminum. The ironing anodized aluminum process can also adopt advanced technologies such as embossing after ironing, one-time forming of embossing, large-area ironing and pressing to make the prints more colorful. Materials made by calendering aluminum foil and plastic composite, or vacuum aluminum plating and secondary composite, can also be used in flexible packaging. It not only increases the metallic luster of flexible packaging and improves the packaging grade, but also has strong sun resistance and UV radiation resistance

imitation metal etching printing

imitation metal etching printing, also known as frosted printing, is a new process emerging in recent years. The printing surface produced by this process can produce a uniform convex material, such as mechanical sandblasting. Especially when printed on metal paper, it can produce a special gloss effect after being corroded by metal, which greatly improves the grade of goods

the imitation metal etching printing process mainly uses UV curing special ink, and uses the missing printing process to achieve the etching effect. The ink material is colorless or multicolor translucent. After being transferred with the metal paperboard, the high gloss part is covered to form a subtle contrast between the weak gloss effect at the inked part and the gloss at the non inked part. At the same time, the feel of the print is frosted, and the overall effect is as elegant as the feeling after metal etching. It should be pointed out that the selection of printing base paper is very important. If the base paper has good metal luster and flatness, the surface effect of the printed product is better, and vice versa. Plate making silk can generally use 180 mesh/inch, fine pattern or 250 mesh/inch. When printing, the ink should maintain a certain viscosity, not too thick, and cannot be mixed with other inks. The best light source power of UV curing device is about 10kW. It is recommended to install 3kw3 or 3kw2. The substrate is in the light area, and it takes 3-5 seconds to solidify the ink. Therefore, the interval distance of the printed matter should be considered, and a cooling device should also be equipped