Analysis of Factors Affecting Pearlescent Effect of Pearlescent Ink

Since ancient times, humans have used pearls as one of the symbols of beauty, because of its unique and beautiful color, which gives people an elegant visual enjoyment. Pearlescent ink offset printing belongs to special glossy printing. Special glossy printing is a comprehensive printing technology that integrates multiple process technologies. It makes the visual effects of printed products elegant and chic or rich and beautiful. Therefore, it is highly praised by people. The packaging field is particularly popular. The emergence of pearlescent printing caters to modern people's needs and thus is widely used. However, in actual printing, the pearl effect of some companies' pearl prints is not very satisfactory. This article will talk about some of their own opinions and hope to help their peers.

Effect of Linking Material on Pearlescent Effect of Pearlescent Ink

Offset pearlescent inks are mainly composed of pigments, binders, thickeners and other additives. Pearlescent ink pigments use pearlescent pigments, which are materials with a floppy effect that can flash different brightness, saturation, hue, and even color depending on the viewing angle. The pigment itself does not have affinity for the fiber, and it is formed on the surface of the substrate to form a transparent resin film with certain elasticity and abrasion resistance by means of the binder material. After printing, the solvent and other liquid medium in the binder material evaporate and then they are on the substrate. A film layer is formed on the film, which is coated with pigment ions and adhered to the substrate, that is, the binder adheres the pigment on the surface of the substrate. Therefore, the role of binders in pearl offset inks is very important. The indicators such as hand feel, various fastnesses, and rheology and dryness of the inks depend to a large extent on the type and quality of the binders. Therefore, the resin selected by Linkage Division should be light in color and moderate in viscosity, and acrylic resins and epoxy resins can be used.

Effect of Pearlescent Pigment Amount on Pearlescent Effect of Pearlescent Ink

The most important component of pearlescent inks is pearlescent pigments, which are luster pigments. The pearlescent effect of pearlescent inks depends on the pearlescent luster of the pearlescent pigments. The pearlescent luster mainly depends on the content of pearlescent pigments in the ink. Changing the amount of pearlescent pigments also changes the pearlescent luster of the printed products. For example, Table 1 is the pair of offset printing. Some of the measured data for pearlescent inks.

From Table 1, it can be seen that pearlescent gloss is getting better with the increase in the amount of pearlescent pigment, and when the amount is 15%, the pearlescent gloss is already very good, similar to the amount of 18%. This shows that when the amount of pearlescent pigment reaches a certain value, the pearlescent effect is basically unchanged. Therefore, the instant amount of pearlescent pigment in the pearlescent ink should be about 15%.

Table 1 Effect of Pearlescent Pigment Consumption on Pearly Effect of Prints

Pigment usage (%) 5 10 15 18 20
Pearlescent luster is better, better, better.

Effect of pearlescent pigment particle size on pearlescent effect of pearlescent ink

The different particle sizes of pearlescent pigments have different gloss sensations and can meet different needs. The small size has a satin-like soft luster, strong hiding power, a large particle size with sparkling luster, and high transparency. When pearlescent pigments of different particle size ranges are mixed, the hiding power and high gloss of the printed product can be taken into account. The finer the particle size of the pearlescent pigment, the more the corners of the incident light can be scattered, and the hiding power of the pearlescent pigment is increased, which means that the transparency of the pigment is reduced and the pearlescent effect is impaired; conversely, the larger the particle size, the greater the hiding power. Insufficient, pearlescent effect is better. The relationship between the pigment particle size of pearlescent ink and its performance is shown in Table 2.

Table 2 particle size and appearance performance

Range of particle size (um) Appearance and performance <15 Flat gloss, good hiding power
5 to 25 satin luster, hiding power is still good
10～40 Pearl luster, moderate hiding power
30～100 glittering pearl luster, low hiding power
20～200 Very strong flickering, poor hiding power

(Xi'an University of Technology Li Xia)

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