Preprint Printing Common Faults and Solutions

1, knife wire

Symptoms: Thin lines appear in the non-graphic part of the printed matter.

Cause: If the position of the cable is fixed, the plate is damaged. If the cable moves within a certain range and the number is fixed, the blade is broken. If there is no obvious rule, there may be more impurities and ink residue.

Solution: Polish the plate or replace the Printing plate with 800-mesh water-sand paper; grind the squeegee or replace the squeegee; check each guide roller, remove impurities, and filter the ink in the recirculating ink path.

2, fog version

Symptoms: The coloring of large areas of non-graphical parts of printed matter.

Causes: Rough surface of the plate; scraper edge is uneven; ink drying speed is too slow; ink transfer is inappropriate.

Solution: Polish the plate with the corresponding water-sand paper; grind the blade or replace it with a new one; add a quick-drying solvent to increase the ink drying speed and replace the appropriate ink.

3, water lines, orange peel

Symptoms: Printed orange peel (especially full-page printing).

Causes: Slow printing speed; low ink viscosity; poor ink flowability, poor leveling; poor surface flatness of the substrate (paper).

Solution: Improve printing speed; add new ink to increase ink viscosity; replace suitable ink; replace paper.

4, hair virtual, halo (ghost), trailing

Symptoms: Imprints in printed matter are not true, fullness is poor, and edges are heavy.

Cause: Improper plate pressure; embossing roller deformation; improper blade angle; ink viscosity is too low.

Solution: Adjust the plate pressure; replace the embossing roller; adjust the blade angle; add new ink to increase the ink viscosity.

5, leaking points, imprinting is not true

Symptoms: Printed texts, especially high-profile parts of the small lines, fine dot blots.

Causes: ink drying speed is too fast; ink viscosity is too high; ink transfer performance does not match; pressure on the embossing roller is too small; the embossing roller is uneven; blade angle is not suitable; paper surface is powder off or too rough; plate life is up.

Solution: Slow drying solvent added to reduce the drying speed; lower ink viscosity; electrostatic ink absorption device; increase the pressure of the imprint; replace the new imprinting roller; adjust the angle of the blade; replace the paper; replace the new version.