Pearlescent ink production and characteristics

1. Pearlescent ink production:

Pearlescent ink is based on pearl powder and different types of advanced resin and different color pigments, after finishing grinding to achieve a certain degree of fineness, viscosity, coloring strength and printability and made of printing ink, suitable for a variety of plastic substrate printing, printing The factory can order the type and name of the ink according to its own desired color. At present, pearlescent red, pearl yellow, and pearl blue produced by Longkou City's labor-use ink are used by many manufacturers, and the effect is very good. It can be printed on the surface or printed on it. After being laminated, it is made into different types of packaging.

2. Pearlescent ink features:

1) The pearlescent powder is translucent and the finer the fineness, the higher the transparency. The fineness of the pearl powder is generally less than 150 μm, and the pearlescent ink is generally about 20 μm.
2) The pearlescent powder in the pearlescent ink is refracted and reflected by light, showing a rainbow of different colors, and is seen as different color samples at different angles.
3) Pearlescent ink is printed on the ink layer of other inks, which can change the color of ink, making red ink redder and blue ink bluer.
4) Pearl powder is an insoluble pigment.
5) After printed with pearl ink, the composite inner layer is generally made of aluminized film, which can better reflect the poor performance of pearlescent powder on the luster surface.

The correct application of pearlescent ink

Pearlescent ink can be directly printed on plastic film, such as PE, PET, BOPP, BOPA, PS and other processed front and back. Currently used for food packaging is the most typical candy paper printing, after the gravure printing film forming. Laminated membranes are generally better coated with aluminum film. However, some printing companies do not purchase pearlescent inks, but instead purchase pearlescent powders for self-blending. They cannot master the properties of pearl powder and diluting agents that have been improperly selected, resulting in many losses and the loss of pearlescent effects. Therefore, in the use of pearlescent ink, pearl ink should be purchased as much as possible manufacturers, the correct use without taking detours.
The following points should be properly mastered during the printing process:

1. When pearl ink is used for printing, pearl ink is generally not used. Instead, the ink is printed on the ink of the empty block printed by other inks to reflect the effect of pearl ink and increase the firmness of the ink. , add new features in the entire package.

2. The use of pearlescent ink is generally monochrome (spot color version). The deeper the depth of plate making will affect the drying speed of the ink layer in the printing process, it will also affect the firmness of the ink, and the phenomenon of blocking and anti-sticking will occur. Therefore, when making plates, we must master the depth of plate making. It is suitable that the general plate-making depth is about 25-45 μm.

3. The angle of the printing blade should not exceed 45°. The printing viscosity can be adjusted according to the speed of the self-equipment. The pressure roller should not be too large. Always pay attention to the scraper to prevent the knife line from appearing.

4. The ratio of pearlescent ink is very high. It is best to use ink pump to circulate ink during printing to prevent precipitation of pearl powder, resulting in inconsistent results of pre-printing and post-printing.

5. When adding a new pearl ink, you should press the pre-printed ink with a thinner in the ink before adding the ink fountain to prevent the pearl powder accumulation phenomenon from being caused when the mixing is not uniform, which will affect the quality of the printed product.

6. When pearl ink and other color inks are used in the second layer printing, it is better to print first color ink and then pearl ink. One is to reflect the pearlescent effect, and the other is to increase the firmness of adhesion.

After the printing is completed, the remaining ink in the ink fountain should not be poured back into the bucket with pearl ink. The empty bucket should be stored separately. When used, new pearl ink is used first and then the previously unused pearl ink is gradually added so as not to affect the reprint quality.

Common problems and solutions

1. Pearl effect or no pearl effect.
1) Check whether the outlets of the printing plate are clogged or the outlets need to be cleaned. The version of the outlet is too shallow to achieve the desired effect.
2) Check whether the viscosity of the pearl ink matches the vehicle speed.
3) Check if the blade angle is too large or the pressure is too high.
4) Check that the distance between the blade and the pressure roller is too long.
2. Stick back, adhesive, adhesion.
1) The ink did not dry out. Increase the drying device, speed up the printing R speed, use fast dry thinner.
2) The plate is too deep and the thickness of the plate is too thick.
3) The pressure is too large, the winding tension is too large or the curl length is too large.
4) The film is damp and the film should be dried before printing.
5) The corona treatment of the film is improper and cannot meet the processing requirements.
3. Pearl powder printing uneven.
1) The contact between the rubber roller and the ink of the serigraphy roller is poor, or the roller is too slippery to cause the print mark to cause uneven color unevenness.
2) The viscosity of the ink is too high. The viscosity of the ink is too high, it is difficult to apply evenly, and it is transferred to the surface of the plate, resulting in inhomogeneities after imprinting.
3) The pressure of the printing pressure roller is uneven. The pressure on both sides of the pressure roller should be adjusted to be consistent.
4) Electrostatic phenomenon. Elimination of static electricity should be done in time, and generally grounding should be used.
5) Check if the pearl powder precipitated. Should strengthen the stirring ability.
6) If you purchase pearl powder blending yourself, you should choose pearl powder and diluting agent to adapt to each other.
4. There is a pearl effect but no gloss.
1) The diluent is too volatile and should be used with a slow-drying diluent.
2) Reduce oven temperature, or cool air.
3) Speed ​​up printing.
4) The ink is too thin. Increase the viscosity of the ink.
5. paste version, blocking version.
1) The ink is dried too fast and the appropriate drying speed should be adjusted.
2) Impurities are mixed in and the surrounding environment is kept clean during printing.
3) Improve printing speed and reduce dry time.
4) Reduce the distance between the cutter and the pressure roller.
6. The peel strength of the printed product is poor.
1) Correctly select the use of pearlescent ink and determine whether it is printed or printed.
2) Choose a suitable glue and thinner.
3) Control the amount of glue, temperature, tension, etc. during compounding.
4) Grasp the corona treatment of the film.
5) If the self-made pearl ink should choose the appropriate diluting agent and composite glue to adapt.

Reprinted from: Ink Information