High-grade packaging special glossy printing

Special glossy printing is a comprehensive printing technology that integrates a variety of process technologies to produce special glossy effects on the surface of printed products. Due to this printing technology, a variety of luxurious, elegant, chic, peculiar and unexpected visual effects can be produced on the surface of printed products, which greatly improves the grade and grade of commodity packaging, and is particularly popular in the field of packaging and packaging. Although some of these technologies use sophisticated and sophisticated equipment, there are also many processes that do not require replacement or investment in equipment. They simply change and adjust the printing process and materials. This is a kind of color ink with a certain amount of bright paste and diluting agent superimposed on the silver layer, and the effect can be achieved. Of course, the transparency of the ink layer is also the key to the pearl effect. This pearlescent printing process is more suitable for letterpress printing because of the interrelationship between silver-base processing and ink overprinting. Lithography should solve the problem of how to print a silver bottom, and then rationally overprint the four-color pattern on it. Due to a variety of changes in light and darkness and tone levels, the formation of print effects + fancy. Of course, letterpress printing can also be based on the process of cross-color printing, two or more different hue, different transparency of the ink layer once overprinted on the print, you can also make this pearl printing step into a new realm.

A certain thickness of ink layer can achieve the effect of crystal luster, so it is especially suitable for screen printing process production.

Pearlescent printing refers to the use of special printing materials and processes to produce a glossy effect similar to that of pearls and shellfish on the surface of printed products, giving people a soft, pleasing and elegant visual appearance.

1. The pearlescent effect can be obtained by printing pearlescent ink. The early pearlescent ink materials were mostly extracted from fish scales. Pearlescent powder sources are limited and the price is very expensive. In recent years, some domestic and foreign scientific research departments have successively trial-produced new materials that have been coated with natural mica or synthetic mica with dioxins. Its luminosity, tinctorial strength, chemical and physical properties are close to and achieve the natural pearlescent effect. It is an ideal pearlescent ink material and has been widely used. Pearlescent printing requires that the printed product should have a certain pearlescent texture. Therefore, the content of pearl powder in the ink is generally not less than 30%, but also requires pearl ink in the print should have a certain thickness, so that the pearl effect is more obvious. Therefore, thicker screens such as screen printing, gravure printing, flexographic printing, etc. should be used. For letterpress printing, similar effects can be achieved if multiple overprints are used. Pearlescent printing also uses paper that has been coated with pearlescent paint, and then printed with ordinary inks. There are also pearlescent powders made into pearlescent powder foil materials that are stamped on the prints, and then embossed. The texture and effect are even more unique.

2. Pearlescent effect can also be used to print a layer of silver or silver ink on the print, and then overprint a layer of very transparent, very thin layer of ink. Because relatively coarse silver particles have a certain degree of flashiness, numerous flash bodies are combined and reflected with each other, and then appear through the transparent color ink layer to form a very delicate special luster. This is another kind of pearlescent effect. This pearlescent printing process requires that the silver layer must be handled well. Silver paste or silver ink with good glittering property should be used first, and other color inks should not be used, and then the transparent ink layer can be doped with substances such as crystals. In the daylight or the change of the lighting angle of the light, it can produce a brilliant and colorful sparkling special effect. Crystalline gloss printing is generally achieved using two processes. One is to form the cat's tie layer on the print with the more private ink, and then move the print to a heat source for drying. The crystalline flash body substance is mostly formed of particles that are colored after the polyester sprayed metal layer is colored, or formed by crushing with a special flash fiber. The other method is to mix the crystalline flash body with a binder to contain the surface of the microparticles as an ink, which is directly transferred to the printed product by printing means. In general, the dry sprinkling method can use coarse grain crystal flash bodies, and its flash effect is better. However, because the particles are easy to float and fly, the work scene is dirty and the operation is troublesome, and it is not suitable for large-scale production. Ink printing methods, although the printing process is simple, hygienic, and suitable for mass production. However, due to the fact that the flash crystal is contained by the ink layer and the factors such as ink transfer are also taken into consideration, the crystal body cannot select too coarse particles, and its flash effect is also relatively poor. Because these two methods must have caused phosphorescent and fluorescent phenomena on the surface of printed matter to be well known, as early as the year of AD 450, there was a record of “Nocturnal Light” on our country’s (later Han Dynasty) and the night pearl of folklore. . In fact, “Nightlight” is an imaginary surface, and the night jewels should contain phosphorus. They heat in friction and they glow in the dark.

Luminescence is the process by which an object converts absorbed energy into light radiation in some way. The phenomenon in which a light body emits light due to an external action is called "excitation" in optics. The difference between fluorescence and phosphorescence is that the path from which the excited molecule drops from the excited state to the ground state is the same, and the time from the excitation to the light emission is not the same. Therefore, when a person cuts off the light source, the presence of phosphorescence can also be seen, and the fluorescence will soon disappear. Luminescent substances are divided into organic and inorganic categories. Inorganic phosphors are red (oxidation memory, yellow-green (zinc sulfide), blue (silver sulfide), etc. These types of phosphors are expensive and are mainly used to coat color picture tubes. The inorganic phosphor powders with lower price are rougher. After lightening, the light-emitting crystals are destroyed and the brightness of the light is reduced.The ink made of this kind of fluorescent powder has poor transparency, strong hiding power, and printing is easy to paste, but its moisture resistance is strong.Synthetic organic phosphorescent powder It contains two parts, the carrier and the stimulant, and the stimulant can stimulate the specific carrier to make the material that does not emit light or emit light to emit light.The different types of the stimulant can also make the wavelength and color of the originally emitted light. Correspondingly, the organic phosphorescent powder has a simple manufacturing process, a low price, a fine grain, and a small loss of brightness after being mechanically ground, and the ink produced by the method has high transparency and low hiding power.

Phosphorescence and fluorescence printing are currently produced using two processes. One is to use light powder as a coating material and produce phosphorescent and fluorescent papers before ink printing. The other is the direct printing of light powder made into ink. There are two methods for preparing the ink: one is to add the binder and the solvent in the light powder, and the ink is made after the ball is ground. The other is a phosphorescent liquid that is directly synthesized as a colorless and transparent liquid, which is naturally dried after printing or dried by uv light curing. It should be particularly pointed out that phosphorescent and fluorescent inks should be on the top layer of the print, that is, the last layer of the print, to prevent the general ink color from covering the phosphor color. Because the phosphorescent color is printed on other ink colors, black, deep purple and other colors will absorb phosphorescence, so that the luminous intensity decreases; white and light colors can improve the luminous brightness. Therefore, try to use light, light tone or reduce the printing level. After processing with microcapsule technology, ink is made and then printed on the print to form a color-changing layer. Under the effect of sunlight and light, the printing product will change its color: from darker to lighter, or from lighter to darker; from colored to colorless, or from colorless to colored. Leaving the light source, it will return to its original shape. 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 packaging, especially in terms of packaging anti-counterfeiting. People only need to take a certain heat source or light source and make contact with a variable ink print, verifying the ink change situation can see the authenticity. In the past, most of the packaging required hot iron. Hot iron and aluminum technology can also be used after the hot embossing treatment, hot convex one-time molding, a large area of ​​hot pressure and other advanced technology to make the print more abundant and diverse. The materials made by calendaring the aluminum foil and the plastic or vacuum aluminum plating followed by secondary compounding can also be applied to flexible packaging. It not only increases the metallic luster of flexible packaging, improves the packaging grade, but also has the effect of strong solar radiation and anti-UV radiation.

Variable gloss printing refers to a printing process in which a special ink or material is used to produce a print and the print can produce a change in gloss under a certain energy. At present, it can be divided into two kinds of thermochromic and photochromic printing processes.

1. Thermochromic printing process. The process is to use some of the substances that can generate color change when exposed to heat, such as: metal iodides, complexes, double salts and liquid crystal materials, etc., and the ink is made to form a color change layer on the printed products. Prints can change color with changes in temperature and outside heat conditions. Thermochromic inks can be divided into reversible thermochromism and irreversible thermochromism. The former means that after the heat source is removed, the color can be restored to its original state. The latter means that after discoloration, it cannot be restored. According to related information, the key to the production of thermochromic ink materials is the use of microencapsulation technology to treat the colorants, discoloration materials, etc., and then add inks such as binders and fillers. The color ink thus obtained can make the color change vivid and sensitive without being affected by other reactive substances, and can improve its heat resistance, durability and washability.

2. Photochromic process printing. Photochromic process printing is the use of photosensitive metallurgical materials, metal gloss printing should have a certain connection with the printing process. In the process of printing iron, people find that the more transparent ink is printed on tinplates that have been coated, polished, and mirror-finished. The printed products can produce a glittering, translucent, splendid effect, making people feel very high-grade. Affected by this, due to the appearance of vacuum aluminum plating technology, metal cardboard and anodized aluminum materials are gradually being introduced into the paper and plastic composite packaging field. Metal cardboard is also called aluminum foil paperboard. One of its production processes is to adopt calendering method to make aluminum aluminum into ultra-thin aluminum foil and compound it with paperboard. The other is to apply plastic film after vacuum aluminum plating. Composite paper. In general, metal cardboard has a smooth surface with a mirror effect, no micropores, and poor printability. It should be printed with ink with strong adhesion. In addition, the amount of ink is also very important, large amount of ink is not easy to dry the conjunctiva, while affecting the transparency of printed products, easy to bring dirty. The ink is small and does not cover the bottom. Practice has proved that the use of uv light-curable ink printing process can make the ink instantly dry, the effect is better. Anodized aluminum stamping materials are also another process of metallic gloss printing. Electro-aluminum, also called 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. Imitation metal etching printing, also known as frosted printing, is a new process that has only emerged in recent years.

The surface of the printing product produced by this process can produce a uniform, such as mechanical sandblasting convex material, especially printed on metal cardboard can produce a special gloss effect of the metal after corrosion, greatly improved Product grade.

Imitation metal etching printing process is mainly used uv light curing special ink, using screen printing process to obtain the etching effect. The ink material is colorless or multi-color translucent. After printing on the metal cardboard, the high-gloss portion is covered so that a subtle contrast between the weak gloss effect formed at the ink and the bright gloss at the non-inking region is formed. At the same time, the feel of the printed product is matte, and the overall effect is very elegant if the metal is etched. It should be pointed out that the choice of printing paper bottom paper is very important. The metal glossiness and flatness of the bottom paper are good, and the surface effect of the printed product is better, and vice versa. Plate-making screens can generally use 180 mesh/inch (1 inch = 2.54 cm) and fine patterns can use 250 mesh/inch. When printing, the ink should maintain a certain degree of consistency, not too thick, and it must not be mixed with other inks. The uv light curing device has a light source power of about 10 kW. It is recommended to install 3kW 3 sticks or 5kW 2 sticks. Substances in the light area must undergo 3 to 5 seconds to cure the ink. Therefore, the distance that the prints pass should be considered. At the same time, it should also be equipped with cooling and cooling devices.

Refractive printing is a new printing process that emerged in the early 80s of the last century. Can make the surface of the printed product has a novel and unique metal mirror refractive effect. The refraction printing is produced by the imprinting method, so that the printed article reflects the change of light according to the principle of light diffusion, and makes full use of the surface state of the paper to make it have