Analysis of Packaging Special Luster Printing (I)

In recent years, consumers have no longer used packaging as a protective product, but have begun to increase their demand for beauty. The attention of consumers has been attracted and intoxicated by some high-end printing and packaging products that are magnificent, elegant, unpredictable, and lustrous. They also inspire the desire to purchase goods, which is special glossy printing.

1, the special glossy printing concept

Special glossy printing is a comprehensive printing technology that integrates a variety of process technologies to produce special gloss effects on the surface of printed products. Due to the use of this printing technology, a variety of luxurious, elegant, chic, peculiar and unexpected visual effects can be produced on the printing surface, which greatly improves the grade and grade of commodity packaging, and is particularly popular in the field of packaging and decoration. Although some of these technologies use sophisticated and sophisticated equipment, there are also many processes that do not require replacement and input. Some are merely changing and adjusting printing processes and materials. This is a very new type of printing technology.

2, pearl printing

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

2.1 Pearlescent effect can be achieved in the pearl ink through print transmission. The early pearlescent ink materials were mostly extracted from natural fish scales. Pearlescent powder sources are limited and the price is very expensive. In recent years, some research institutes at home and abroad have successively trial-produced new materials coated with titanium dioxide, natural mica or synthetic mica. Its luminosity, tinting strength, chemical and physical properties all accept and achieve natural pearlescent effect. It is an ideal pearlescent ink material and is now 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 silk prints, gravure printing, flexographic printing, etc. should be used. For letterpress printing, similar results 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.
2.2 Pearlescent effect It is also possible to apply a layer of silver or silver ink on the prints and then to superimpose a very transparent, very thin ink layer. 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 or silver ink with good glittering property should be used first, and other color inks should not be mixed. Then, a certain amount of bright paste is added, and the color ink of the dissolving agent is superimposed on the silver layer, and the effect can be achieved. Of course, the transparency of the ink layer is also a good and bad relationship of pearl effect. This pearlescent printing process is more suitable for letterpress printing because of the interrelationship between silver-base processing and ink overprinting.

3, crystal glossy printing

Crystalline luster refers to a substance that is crystal-like in the printed material or in the transparent ink layer. In the daylight or the light incident angle changes, can produce a brilliant and colorful sparkling special effects. Crystalline luster printing is generally achieved by two processes: one is to first form a bonding layer with a large viscosity ink on the printed product, and then move the printed product to a heat source for baking. The crystalline flash body substance is mostly made of particles that are colored and powdered after dyed with polyester, or formed by crushing with a special flash fiber; the other is that the crystalline flash body is blended with a binder to encapsulate the surface of the particles into an ink, and the ink is printed. Means are passed directly to the prints. Since the flash crystal is contained by the ink layer, and the factors such as ink transfer must also be considered, the crystal body cannot select too coarse particles, and its flash effect is also relatively poor. Because these two methods must make the surface of the printing product to form a certain thickness of ink layer to achieve the effect of crystal luster, so it is particularly suitable for screen printing process production.

4, fluorescence and phosphor printing

Phosphorescence and fluorescence have long been known. As early as the year 450 AD, there was a “night light” record in China’s “The Later Han Dynasty” and the night phoenix of folklore. In fact, the "luminous wall" is an imaginary surface, and the night luminescent pearl should contain phosphorus. They will glow in the dark after being heated by friction.

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 different, and the length of time from the excitation to the light emission is different. Therefore, when the incident is eliminated and cut off, 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 include red (yttrium oxide), yellow-green (zinc sulfide), and blue (silver sulfide). This kind of phosphor is expensive and is mainly used for coating color picture tubes. Synthetic organic phosphors, containing both carriers and stimulants. The stimulant function can stimulate the specific carrier to emit light that does not emit light or emit light. The different types of stimuli can also change the original light, wavelength, and color. This organic phosphor powder has a simple manufacturing process, low price, fine particles, and small loss of brightness after mechanical grinding. The ink made with it 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 kinds of ink preparation methods: one is to add the binder and solvent in the light powder, and the ink is made after ball milling; the other is to directly synthesize as a colorless and transparent phosphor liquid, which is naturally dried or UV-cured after printing. dry. In particular, it should be pointed out that the phosphorescent and fluorescent inks should be on the top layer of the print, that is, the last color 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 phosphorus, so that the luminous intensity decreases; white and light colors can increase the luminous intensity. Therefore, try to use light, light tone or reduce the printing level.