Digital Magazine

Understanding Anilox Scoring: Causes, Effects, and Prevention

Anilox scoring, a persistent issue in the printing industry, continues to challenge printers despite numerous discussions about its root causes and preventive measures. In this O&A article, we aim to delve deeper into this topic to help printers better understand the underlying factors and implement effective solutions.

What is Anilox Scoring?

Anilox scoring occurs when the cell walls of the anilox roll break down around its circumference. Instead of having individual cells for carrying and transferring ink, you have one long gouge line around the circumference of the anilox that, the degree of severity will show as either a dark or light line.

How do you Identify Anilox Scoring vs. Plug Lines?

Lighter lines are a less severe form of scoring that are the result of the top of the cells being polished off. When the tops of the cells are polished off, the cell is no longer intact and able to carry and transfer ink thus showing as a lighter line. The lighter line can also be the result of plugged cells that create the same issue with the cells incapable of holding and transferring ink, sometimes referred to as plug lines.

When darker lines are seen in the printed image or anilox itself, it's a more severe form of score where an actual gouge is present. These lines cannot be reversed, necessitating recoating of the anilox roll. Plug lines, however, can often be addressed through thorough cleaning before considering recoating.

What are the Common Causes of Anilox Scoring?

These are the most common root causes of score lines that Provident, LLC notices when doing an inspection.

  1. Doctor Blades: Improper positioning of doctor blades against the anilox can lead to scoring. Misaligned blade chambers or excessive pressure on the blades can further damage the anilox cell walls.
  2. Ink: Ink particles that aren't properly ground down can become lodged between the anilox and blade, contributing to cell wall breakdown or plugging.
  3. Debris: Debris picked up by web-based unwind stations or transferred from the environment can accumulate between the blade and anilox, causing damage.
  4. Defective Anilox Rolls:
Anilox rolls may have defects such as recast or slag, which can damage the cell walls. Engraving irregularities, especially on lower LPI anilox rolls, can also contribute to scoring.

How do you Prevent Anilox Scoring

Knowing what's causing the scoring helps, but it's not always easy to identify the smoking gun when it comes to this issue. These are the most common best practices we find to be the most effective:

  1. Proper Training: Train operators on installing and aligning doctor blades and establish auditing procedures to ensure alignment with best practices.
  2. Use the Right Tools: Employ magnets in ink pumps and solvent lines, and use filters for inks and solvents to capture particles.
  3. Incoming Anilox Inspection: Regularly inspect incoming anilox rolls to ensure they meet expectations and identify any issues early.
  4. Cleaning Procedures: Implement rigorous cleaning procedures for both the press and surrounding areas to prevent debris buildup.
  5. Leverage Vendor Expertise: Utilize vendor expertise to address issues and optimize processes for success. As a technical representative for Provident, LLC, we take pride in only being successful if you are successful.

In conclusion, understanding the root causes of anilox scoring and implementing preventive measures are crucial steps in ensuring high-quality print production. By adopting best practices and leveraging vendor support, printers can mitigate the risk of anilox scoring and achieve consistent print excellence.