The most popular packaging on special gloss printi

Analysis of special gloss printing of packaging (Part 1)

in recent years, consumers have no longer regarded packaging as a body to protect goods, and began to increase their demand for beauty. And what makes consumers' critical eyes attracted and intoxicated by some high-grade printing and packaging that is resplendent, elegant, unpredictable and pearlescent, and arouses the desire to buy goods is special gloss printing

1. The concept of special gloss printing

special gloss printing is a comprehensive printing technology integrating various processes and technologies, which can produce special gloss effect on the surface of printed products. Because this printing technology can produce a variety of luxurious, elegant, unique, strange and unexpected visual effects on the printing surface, which greatly improves the grade and taste of commodity packaging, especially popular in the field of packaging and decoration. Although some of this technology requires more sophisticated equipment, there are also many processes that do not need to be replaced and put into equipment. Some simply changed and adjusted the printing process and materials. This is a new printing technology with great vitality

2. Pearlescent printing

pearlescent printing refers to the use of special printing materials and processes to produce a gloss effect similar to pearls and shellfish on the surface of printed products, giving people a soft, pleasing and elegant visual impression

2.1 the pearlescent effect can be achieved by printing and transmission of pearlescent ink. The early pearlescent ink materials were mostly extracted from natural fish scales. The source of pearlescent powder was limited and the price was very expensive. In recent years, some scientific research departments at home and abroad have successfully developed new materials coated with titanium dioxide, natural mica or synthetic mica. Its luminosity, coloring power, chemical and physical properties all accept and reach the natural pearlescent effect. It is an ideal pearlescent ink material, which has been widely used. Pearlescent printing requires that the printed matter should have a certain pearlescent texture. Therefore, the content of pearlescent powder in the ink is generally not less than 30%. At the same time, it is also required that the pearlescent ink should have a certain thickness on the print to make the pearlescent effect more obvious. Therefore, we should use silk screen printing with thick imprint, gravure printing, flexible printing with the characteristics of light weight, high strength and versatility, etc; Relief printing can also achieve a similar effect if it adopts multiple overprint. Pearlescent printing also uses paper coated with pearlescent paint and then printed with ordinary ink; There are also pearlescent powder foil materials made of pearlescent powder, which are hot stamped on the printed products, and then embossed. Its texture and effect are more unique

2.2 the pearlescent effect can also be achieved by first laying a layer of silver paste or silver ink on the print, and then overprinting a very transparent and thin color ink layer. Because the relatively coarse silver powder particles have a certain flash, many flash bodies are combined to reflect each other, and then appear faintly through the transparent ink layer, forming a very subtle special gloss, which is another pearlescent effect. This pearlescent printing process requires that the silver layer must be treated well. Silver paste or silver ink with good flash should be used first, and other color inks should not be mixed. Then a certain amount of bright paste should be added to the full intelligent wood-based panel universal testing machine, and the color ink with diluent removed should be overprinted on the silver layer, and the effect can be achieved. Of course, the transparency of the ink layer is also related to the pearlescent effect. This pearlescent printing process is more suitable for relief printing because of the relationship between silver bottom treatment and ink layer overprint

3. Crystal Gloss printing

Crystal Gloss refers to the crystalline substance hidden in one side of the print or the transparent ink layer. Under the change of the incident angle of sunlight or light, it can produce a colorful and glittering special effect. Crystal Gloss printing generally adopts 1 The low temperature constant temperature bath adopts the air-cooled fully enclosed tightening mechanism, and uses two processes to achieve cold: one is to first put the printing product on the viscous ink to form a bonding layer, and then move the printing product to the heat source for drying. Crystalline flash materials are mostly made of particles crushed after coloring with tapestry sprayed metal layer, or formed after crushing with special flash fibers; The other is to mix the crystal flash with the connecting material to contain the particle surface into ink, which is directly transmitted to the print by printing means. Because the flash crystal is contained by the ink layer, and factors such as ink transmission should also be considered, the crystal cannot choose too coarse particles, and its flash effect is relatively poor. Because these two methods must form a certain thickness of ink layer on the surface of the print to achieve the effect of crystal gloss, they are especially suitable for the production of silk leak printing process

4. Fluorescence and phosphorescence printing

the phenomenon of phosphorescence and fluorescence has long been known to people. As early as 450 A.D., there were records about "luminous wall" and the night pearl of folklore in the book of the later Han Dynasty in China. In fact, the "luminous wall" is a kind of fluorescent surface, and the luminous pearl should contain phosphorus. After friction and heating, they will glitter in the dark

the difference between fluorescence and phosphorescence is that the excitation molecules fall from the excited state to the ground state in different ways, and the length of excitation to luminescence time is also different. Therefore, when the incidence is cut off, the presence of phosphorescence can be seen, and the fluorescence will disappear soon. Luminous substances are divided into organic and inorganic. Inorganic phosphors include red (yttrium oxide), yellow green (zinc sulfide), blue (silver sulfide), etc. This kind of phosphor is expensive and is mainly used to coat color kinescope. Synthetic organophosphorous phosphor consists of two parts: carrier and excimer. The excimer can excite a specific carrier to make the material that does not emit light or emits weak light. Different varieties of excimer can also change the original light, wavelength and color. This organic phosphor powder has simple manufacturing process, low price, fine particles and small loss of luminous brightness after mechanical grinding. The ink made of it has high transparency and low hiding power

more flexible phosphorescence and fluorescent printing are currently produced by two processes. 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 ink 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 phosphorescent color. Because phosphorous light color is printed on other inks, while black, dark purple and other colors will absorb phosphorous, reducing the luminous intensity; White and light colors can improve the luminous intensity. Therefore, try to use light and light tone or reduce the printing level