Factors Affecting the Quality of Flexo Printing Products (1)

There are many factors that affect the quality of flexographic printing products, such as platemaking, operation and technology, equipment and materials, and so on. There are many aspects in terms of ink. Flexo printing ink is more.

Water-based inks belong to Newtonian fluids, so the stability of inks is poor, mainly in the following three aspects:

I. Precipitation of ink pigments. Before use, the ink in the ink tank should be evenly stirred, and the ink in the ink tank should be often stirred during the printing to prevent the print color and standard from having certain differences due to the precipitation of the ink pigment. An effective way is to use a fully enclosed scraper so that the ink is always in agitated and fluid state under the operation of the ink pump.

2. During storage and use, the pH value decreases (tend to be slightly alkaline) due to volatilization of the stabilizer in the ink composition. In the use of water-based ink stabilizer is volatile, so that the ink tends to be weakly alkaline, resulting in increased surface tension, the adhering force on the surface of the printing plate will be decreased, affecting the transfer performance and drying speed (ink more alkaline, dry Faster speed. This will result in the incompleteness of printing artwork in the printing process. Especially when printing the cable version, the ink is dried too quickly, causing the printing outlets to be lost or the cable version to be blocked.

3. In the use of ink due to the volatilization of water, resulting in increased ink viscosity, flow properties weakened. Some ink supply methods for printing equipment are single-squeegee systems that require the ink to have a certain degree of viscosity and fluidity so that it is in a relatively suitable range. When the ink in use in the degree of clarity and fluidity exceeds the requirements of the printing use, it will affect the ink transfer performance, there is a large solid surface printing print "color."

Factors affecting the quality of flexographic products in print materials include the flatness of the printed material surface, the absorbency of the material, and the surface strength of the material.

The flatness of printed materials is a necessary prerequisite for the printing of large-area field layouts. Due to the rough surface of some of the materials, the surface of the printed product is not clearly printed. By increasing the printing pressure, although the problem can be solved on the surface, the text on the printed page is blurred or the “edge effect” of the printed matter is obvious.

Absorption of materials For printing, good absorption of material is both beneficial and disadvantageous. Advantageously, due to good absorption, the adhesion of the ink to the material is not easy to fall off; the disadvantage is that the absorption of the material is strong, resulting in increased use of ink, such as the domestic oil-proof paper is particularly prominent.

The surface strength of the material is now used for the printing of paper on the tray paper, the surface strength is poor, and the paper powder falls more, resulting in the need for frequent wipes during the printing process.

In addition, the following are the factors that affect the quality of the product:

1. Printing plate graphic design such as a light gray flat net, in the design, try to design with a spot color, to avoid the use of yellow, red and blue overprint, because it is difficult to control the gray balance.

2. The type of product structure such as large-area color patches and blanks, and a section of blank space on the ground, which are inconsistent in the amount of pressure, will cause the printing roller to jump, causing inconsistent printing site compression.

3. The configuration of the anilox roller As the anilox roller of the printing factory is configured with 600 to 700 lines, when producing 150 lines of products, I% to 2% of the dots will be embedded in the anilox roller network, affecting the quality.

4. Solid content of ink If the solid content of the ink is too low, the number of anilox roller lines must be reduced in order to achieve a certain color density during printing production. This will slow down the drying speed of the ink. If it is a cable version, it is easy to block the plate.

5. Flatness of the printing plate If the printing plate has a poor flatness, the pressure on the entire surface of the printing plate is inconsistent during the printing. To ensure that the entire printing plate can be printed, there will be some pressure on the printing plate position and the dots will be enlarged. is too big.