Talking about the application of pearl pigment in ink printing

Over the years, people have admired the seductive luster of pearls. It would be a wonderful thing to see them everywhere in life. But it was not until the middle of the 20th century that this special pigment that could emit pearl luster was used in printing. This is a product called "mica titanium pearlescent pigment", commonly known as pearlescent pigment. Its appearance makes the decorative effect of printed matter richer. At present, with the continuous development of the printing industry, especially the increasing market demand for high-quality packaging, the application of pearlescent printing is becoming more and more extensive.

Excellent performance of pearl powder

This kind of pearlescent ink, which has attracted the attention of the printing industry and has gradually become popular in the market, is what technology is used? In fact, it is very simple. It is prepared by mixing pearlescent powder with solvent-based or water-based inks. It is uniformly dispersed in the translucent ink through the micron-scale wafer layer. Under the action of light refraction and reflection, it reproduces natural pearls, shells, The elegant luster and color of butterflies, fish and metals.

Although the technical principle is very simple, this pearlescent pigment is still very powerful in practical printing applications.

1. good stability

Since pearlescent pigments are inorganic compounds with relatively stable chemical properties, they will not be denatured due to oxidation, acid-base effects, and there are no special requirements for storage, transportation and use. At the same time, pearlescent pigments are not toxic and corrosive, and can be applied to all printing substrates including food packaging, and will not be harmful to the human body.

2. good decorative

It is believed that printing companies that have used pearlescent pigments will have a deep memory of the extraordinary decorative effects they produce on printed matter. Because the pearlescent pigments and inks are very flexible, it is possible to achieve different levels and colors of pearlescent effects through different color matching methods and the concentration of pearlescent pigments in the ink, thereby improving the aesthetics of the printed matter.

3. good adaptability

From a technical point of view, except for offset printing that requires high granularity, the pearlescent effect can be achieved by any current printing method, even glazing (over oil). In terms of substrates, although there are no specific requirements, in order to highlight a good pearlescent effect, a substrate with a smooth and flat surface is more suitable. In the printing operation, except for controlling the printing and drying speed, other operations are the same as usual, so there is no operational difficulty.

4. Economical

In general, the cost of pearlescent pigments is not expensive, and the ink mixed with it can be used in ordinary types. In this way, the same exquisite decorative effect is achieved, and the use of pearlescent pigments is obviously more cost-effective than the use of special-effect substrates.

But this does not mean that pearlescent pigments are perfect, because pearlescent powder in pearlescent pigments is actually made of titanium dioxide (or other metal oxides) coated mica. According to the current process, the particles are still relatively large, so that Precipitation is easy to form, making the ink color lighter and lighter, resulting in color difference. In operation, there are certain requirements for ink viscosity, inking and drying speed.

Pearlescent pigments are suitable for various printing methods

Such pearlescent pigments with excellent performance are not "Wangxietang Qianyan". But it is worth noting that pearlescent pigments also have specific requirements for different printing methods.

1. Pearlescent offset printing

Although offset printing plate making is fast and low cost, and realizing pearlescent offset printing is the goal pursued by many printing manufacturers, compared with the thin ink layer and long ink path of offset printing, pearlescent pigments with larger particles are very difficult in the transfer process. Therefore, to achieve pearlescent offset printing, pearlescent pigments with smaller particle size must be selected, and the ink path should be shortened as much as possible.

2. Pearlescent screen printing

It can be said that screen printing is still very suitable for this large particle size pearlescent pigment, and it can also form more special effects. However, the slow drying speed of the ink in screen printing will affect the final effect of pearlescent ink on the substrate.

The pearlescent printing business of Zhejiang Printing Company has accounted for half of the total business volume, and pearlescent screen printing accounts for 70%, especially the pearlescent screen printing can produce the effect of "different angles, different colors", making the cigarette factory's cigarette labels sparkle Shenghui.

3. Pearlescent Gravure

The thick ink gravure is of course very suitable for the application of pearlescent pigments, and in fact it is also the most widely used field of pearlescent pigments in actual production. However, the high cost of gravure printing itself makes pearlescent printing not available for large-scale production applications. Henan Printing Co., Ltd. uses gravure printing to finish the cigarette label with pearlescent effect, and the cigarette label box printed with pearlescent ink has comprehensively improved the grade and ornamental value of the product and increased the added value of the product. It was also after the company introduced pearl gravure that it attracted a lot of business.

4. Pearlescent Flexographic Printing

Using pearlescent pigments of different color sequences or different particle sizes can achieve rich pearlescent effects in flexographic printing. In fact, flexographic printing is also the pearlescent printing method that is gradually emerging, but it is also affected by flexographic plates. , Constrained by the high price of anilox rollers.

At drupa 2004, we were delighted to see that some printing machinery manufacturers have launched coating equipment connected to offset presses, using flexographic printing, laser ceramic anilox rollers to transfer ink, enhancing the transferability of pearlescent pigments, and at the same time It also uses offset printing to improve production efficiency. It is believed that with the continuous development of technology, the contradiction between pearlescent printing in production efficiency, printing effect, production requirements and manufacturing costs will be solved.

Purchasing of Pearlescent Pigments

When purchasing pearlescent pigments, you must first thoroughly understand your own production process.

1. Consider the particle size of pearlescent pigments

For pearlescent pigments with larger particle size, screen printing is best, while gravure printing can be used for smaller particle size. In the field of packaging, in order to highlight the graininess of the pearlescent effect, many printing manufacturers choose pearlescent screen printing. In this way, due to the large and numerous pearlescent pigment particles, when the light hits the surface, it will reflect a lot, strengthen the brightness of the color, and produce "shiny". "Effect.

2. Consider the thickness of the substrate

In screen printing and gravure printing using pearlescent pigments with smaller particle size, in order to facilitate the transfer, it is necessary to apply a large pressure on the surface of the printing material, so that if the surface of the printing material has insufficient pressure resistance, it is easy to cause deformation of the substrate. Or break.

3. Comprehensive consideration of printing costs

It is not that pearlescent pigments are cheap, and pearlescent printing costs are low. As mentioned earlier, in order to avoid the precipitation of pearlescent pigments in the printing process, it is necessary to speed up the drying speed of the ink. The best solution is to use UV printing, but once the UV ink is used, the overall cost will increase. In addition, the cost of flexographic printing and gravure printing is quite high, but at the same time, this is also the most suitable printing method for pearlescent effects, so consider carefully when purchasing pearlescent pigments.