Printed ink color five phenomena can not be underestimated

[Chinese Packaging Network News] First, the printing plate substrate material characteristics do not cause the phenomenon of ink printing flowers

Maintaining a consistent packaging printing pressure is essential for ensuring the quality of printed materials. Several factors influence this pressure, including the accuracy of the equipment and the properties of the printing plate's base material. For example, in letterpress or round flattening packaging presses, copper, zinc-plated, or resin plates are often used, and these require a base plate to hold the printing plate securely during the process. The base tray plays a crucial role in maintaining stable printing pressure, as it must be solid, firm, and resistant to deformation to ensure uniform ink transfer. Traditional wooden substrates, however, have several disadvantages, such as poor durability, susceptibility to overprinting, and issues with ink transfer, which can lead to uneven or insufficient ink layers. These problems arise due to the instability and tendency to deform of wood, making it difficult for ink to be evenly transferred to the printed sheets. To avoid this, proper padding techniques should be applied, ensuring even and adequate cushioning. For large-area packaging, using metal die pads—such as magnetic trays or aluminum trays—can provide better flatness, strength, and stability, effectively preventing ink blooming and ensuring high-quality print results.

Second, poor machine condition or improper adjustment can cause ink blooming

When machines age, components like roller shafts, bearings, gears, and ink rollers may wear out or become loose, affecting the stability of the printing pressure and ink distribution. This can result in ink blooming, especially when printing large areas. To prevent this, regular maintenance is essential, particularly for parts like embossing units and ink roller bearings, to ensure they remain well-lubricated and free from excessive wear. Additionally, improper positioning of the ink roller can also lead to ink blooming. Ensuring that the ink roller makes even contact with both the skewer iron roller and the printing plate, with moderate pressure, is key to avoiding such issues.

Third, issues with the lining material can lead to ink blooming

The lining material acts as a medium for transferring ink and pressure during the printing process. Its material properties and quality directly impact the final ink quality. If the lining has a high deformation coefficient or poor flatness, it can cause ink to bloom on the printing plate. Therefore, selecting the right lining material based on the specific requirements of the packaging and printing job is crucial. For soft resin plates or textured plates, rigid linings made of materials like cardboard, kraft paper, or insulation paper are recommended, as they offer good stability and reduce the risk of ink defects. On the other hand, for hard copper or zinc-plated plates, elastic materials like cloth, blankets, or fine-grained paper are more suitable, as they help maintain even ink transfer and prevent color inconsistencies.

Fourth, ink discoloration caused by the printing material

Zinc plates, when used for large-area printing, are prone to ink blooming due to various reasons, such as surface oxidation forming "sand-eye" patterns, excessive baking temperatures, or an overly strong etching solution. These conditions can reduce the ink affinity of the plate, leading to poor contact between the ink layer and the printed sheet, resulting in ink defects. To address this, the printing plate surface can be gently ground with charcoal to reduce roughness, and the printing pressure and ink supply should be adjusted appropriately. For fine-print packaging jobs, using a solid resin plate is recommended, as it offers better gloss and ink adhesion, reducing the likelihood of ink blooming and improving overall print quality.

Fifth, ink blooming caused by poor paper quality

Paper with a rough surface tends to absorb more ink due to the gaps between its fibers. This can lead to poor contact between the paper and the printing plate, requiring more ink to achieve the desired coverage. If the printing pressure is too low or the ink layer is too thin, it can result in ink blooming on the printed product. To avoid this, the printing pressure should be increased for papers with poor printability, and the ink application should be carefully controlled to ensure even coverage and proper absorption. This helps maintain the quality of the printed ink and prevents undesirable defects.

After reading the above, I believe that the issue of ink coloring is no longer something that troubles you. For more information, feel free to continue following China Packaging Network!