Common problems in gravure printing

Date: Sep 25 2024 From: Star Color

As a common printing method, gravure printing has the characteristics of thick ink layer, bright colors, and fine graphics and text. However, it also encounters some common problems in the actual production process. Here are some common gravure printing problems and their solutions:

Drying speed issue

Problem manifestation: Slow drying speed can cause contamination, adhesion, and excessive residual solvents on the guide rollers.
Reason: The solvent drying speed is too slow, the plate depth is too deep, the dryer capacity is insufficient, and the printing speed is too fast.
terms of settlement:
1. Choose a solvent with moderate drying speed.
2. If a deeper version is required, it should be combined with a fast drying solvent and the printing speed should be slowed down.
3. The printing speed should be determined by the capacity of the dryer, and drying mainly relies on air volume, followed by temperature.

Common problems in gravure printing

Surface foaming problem

Problem manifestation: A large number of bubbles appear in the printed product, affecting the scraper function.
Reason: The nature of the ink itself (such as water-based ink being more prone to foaming), and defects in the ink circulation system.
terms of settlement:
1. Add precise dosage of defoamer specified by the ink factory, and be aware that excessive dosage may promote foaming.
2. Detect and optimize the ink circulation path to avoid violent ink movement and large drops.

Peeling problem

Problem manifestation: After the ink surface in the ink tray dries, it adheres to the drum, forming unevenness, scraper marks, or contamination.
Reason: The ink drying speed is too fast, and the air leaked from the dryer dries the surface of the ink.
terms of settlement:
1. Adjust the ink drying speed so that the exhaust air volume of the dryer is slightly greater than the supply air volume.
2. To prevent air from leaking out of the dryer, cover the ink tray appropriately to avoid wind blowing onto the ink.

Anti sticking printing problem

Problem manifestation: The ink printed on the previous version sticks to the next version of the layout.
Reason: The ink film from the previous version dissolves onto the next version.
terms of settlement:
1. Ink from the second edition onwards should be diluted with solvents with slightly weaker solubility.
2. The printing speed should not be too slow to avoid ink staying on the page for too long.

Network cable issue

Problem manifestation: Ink transfers to the film in a dot like state, forming independent small dots in the shaded areas.
Reason: The ink dries too quickly or has a high viscosity, and it has already dried and solidified before the ink is even; The mesh width is too wide during plate making.
terms of settlement:
1. Use a solvent that dries slowly.
2. Move the scraper forward as much as possible and pay attention to the leakage seal of the dryer.
3. While ensuring appropriate fluidity, try to use low viscosity ink for printing.

Color change issue

Problem manifestation: The ink transfer in the shaded area is uneven, resulting in small uneven shades.
Reason: The intaglio depth is too deep and the ink viscosity is too low, which affects the fluidity of the ink; The ink temperature is low.
terms of settlement:
1. Use solvents that dry quickly.
2. Printing with high viscosity ink.
3. Change the angle and number of lines of the plate mesh during plate making.
4. Heat the ink with hot water before use to improve its fluidity.

Anti sticking problem

Problem manifestation: The ink layer of the rolled printed matter adheres to another contact surface (such as the back of the film), causing ink peeling and printed matter contamination.
Reasons: Poor drying, softening of ink caused by temperature rise, excessive winding tension, insufficient ink adhesion, insufficient ink cohesion, and strong affinity between the contact surface and ink.
terms of settlement:
1. Make full use of the cooling roller and store printed materials in a cool and shady place.
2. Pay attention to the winding tension and avoid excessive tension.
3. If necessary, contact the ink manufacturer and take appropriate measures to improve the adhesion and cohesion of the ink.

Gravure printing workshop

Other common problems and solutions

1. Uneven ink color: Correct the roundness of the printing plate cylinder, adjust the angle and pressure of the ink scraper, or replace it with a new one.

2. Imprint smudging and fuzzing: Remove static electricity from the surface of the substrate, add polar solvents to the ink, increase the printing pressure appropriately, and adjust the position of the ink scraper.

3. Blockage: Increase the solvent content in the ink, reduce the ink drying speed, and use paper with high surface strength for printing.

4. Ink overflow: Add hard ink adjusting oil to increase ink viscosity, adjust the scraper angle, increase printing speed, and replace the deep mesh printing plate with a shallow mesh printing plate.

5. Scratches: Use clean ink without foreign objects mixed in for printing, adjust the viscosity, dryness, and adhesion of the ink, use a high-quality scraper blade, and adjust the angle between the scraper blade and the printing plate.

6. Pigment precipitation: Use ink with good dispersibility and stable performance for printing, add anti coagulation and anti precipitation additives to the ink, fully roll and frequently stir the ink in the ink tank.

In summary, there are various problems encountered in the gravure printing process, but most of them can be effectively solved through reasonable adjustments and optimization measures.

Zhongzhixing gravure water-based ink has good printing adaptability and can be directly used on the machine without excessive adjustment. High adhesion, able to firmly adhere to the surface of the substrate, not easy to peel off or fade. More environmentally friendly than solvent based ink, welcome to consult.