Pearl powder and dilute agent

Pearlescent pigments have been available for more than 70 years, and have a long history in the printing industry. Pearlescent pigments have been widely used in paper printing in various parts of the world. Different kinds of printing processes and products, such as lithography and gravure printing, have been widely used.

Products are mainly used in paper printing such as soap packaging paper, cigarette packs, cigarette holders, greeting cards, wallpaper, food packaging paper, etc.; film printing, such as PET, PE, OPP, PS, etc., due to the wide use of pearlescent pigments, now mainly introduces pearlescent The use of pigments in gravure printing.

In gravure printing, pearlescent powder can be directly added into the printing dilute to the agent. The amount of pearl powder used can be added with the customer's requirements. Up to 30% (weight ratio) can be added. The printing manufacturer can purchase pearlescent pigments directly and directly mix in the print dilute. Used in the agent.

Pearlescent powder belongs to insoluble pigments, and it needs to rely on a very good diluting agent to make the pearl powder completely wet and dissolved. The effect can be perfect after printing.

1. Mix of pearl powder and diluting agent

Pearlescent powder is a kind of crystal powder. When it is blended with diluting agent, if it is handled improperly, it can easily stick into a spherical shape, resulting in the formation of pinholes in the printing, poor printing gloss and other ills. Therefore, it is very important to use a good diluting agent. In order to prevent the pearlescent pigments from sticking to each other and open into small balls, the required pearl powder must be weighed and then gradually added into the diluting agent to adjust evenly to avoid binding of the pearl powder in the diluting agent. For example, the printing viscosity is too high. Add some diluent (such as isopropyl alcohol, ethyl ester) as appropriate.

If you need color pearl effect, you can add 0.5-1% of ordinary color ink in the adjusted pearl powder, you can achieve color pearl effect.

Pearlescent ink sometimes has a deposition phenomenon during its use. It adopts a cyclical operation of the storage tank and uses low-speed stirring to keep the pearl powder flowing. At the same time, the ink is used to guide the ink to the ink tray for printing. The remaining pearl ink is then piped. Return to the ink tank, this device can prevent precipitation of pearl powder, while maintaining color stability. The engraving depth of the plate roll is also related to the printing effect. If anti-settling agent is added to prevent sedimentation, the ink concentration will increase, the fluidity will decrease, and the printing requirements will not be met. This problem is worthy of attention by manufacturers.

2. The choice of pearl powder

As mentioned above, the particle size of pearl powder has a great relationship with the depth of engraving of the printing plate. If the engraving depth of the plate is not enough, the ink will only be transferred during printing and the pearl powder will remain in the ink tank. , leading to more and more serious precipitation and common ups and downs.

Before ordering pearlescent pigments, it is necessary to understand the pearlescent effect required by the product in order to determine which type of pearl powder is most suitable.