Practical experience in label printing: "Cloudy" print image in halftone printing

02.03.2016

In our series "Practical experience in label printing," we address everyday challenges in label printing and how to solve them. In this issue, we focus on the topic of "cloudy" print images in screen printing.

problem detection

"Cloudy" print image in grid printing. Often occurs with self-adhesive papers and PE labels.

Troubleshooting:

• The combination of adhesive tape, printing plate, and substrate is unfavorable. In this case, certain printing plates require a softer adhesive tape, while others require a harder adhesive tape. However, as a general rule, use a soft adhesive tape for screen printing.
• Harder printing plates are more prone to "clouding." To prevent cloudy halftone images, use softer printing plates.
• Check and correctly adjust the pressure settings between the anilox roller and the printing plate and between the printing plate and the substrate.
• Clean the screen roller thoroughly.
• Use a screen roller with a higher lineature (L/cm).
• The surface tension of the substrate is too low or too high. Increase or decrease corona surface pretreatment.
• Check the quality of the surface of the print substrate and use a new roll if necessary.
• Use paper with a better line quality (high-gloss paper)

Without clouds

With clouds

(Roger Oberholzer Process Engineering)