As we continue the Anilox 101 educational series, we must discuss anilox damage and defects. As the heart of the flexo printing process, the anilox must be manufactured to perfection and handled with care to be effective. In this blog, Apex International, the global leader in anilox roll and sleeve manufacturing, will discuss the top anilox damages and defects found in the pressroom and how to prevent and resolve these issues.
Top Anilox Damages & Defects
Some of the most common anilox damages and defects are anilox roll scoring, anilox corrosion, roll inconsistency, and roll or sleeve chips/cracks.
Anilox Scoring
Anilox scoring occurs when metal debris or other hard particles are trapped between the doctor blade and anilox surface, scoring a vertical shallow to deep line into the anilox cells as it rotates.
This can occur:
- Due to over-pressurized doctor blade-to-anilox contact: The stainless-steel metering blade can wear and break off shards of metal from excessive pressure or running dry, carving lines into the rotating anilox roll. Operators sometimes increase doctor blade pressure to compensate for improper ink transfer or ink leaking, which can lead to damage.
- Due to poor engraving or insufficient polishing: This leaves small, raised pins on the corners of the anilox cells that can dislodge and enter the circulating ink.
Read our blog Top Causes of Anilox Scoring & How To Prevent Them for a more in-depth look at anilox scoring.
Anilox Corrosion
The anilox roll is made up of a steel, stainless steel, or aluminum base. These metals, except for stainless steel, are susceptible to corrosion and oxidation depending on material quality and exposure.
Most anilox manufacturers apply two coating layers:
- A corrosion-resistant bond layer covering the steel base to prevent corrosion. This can vary in corrosion-resistant properties from supplier to supplier.
- A ceramic surface coating for engraving. The ceramic powder and application method determine the porosity percentage and the coating's compactness.
Many manufacturers apply a sealant to mask porosity and less compact coatings. However, Apex does not apply sealant due to our superior compact ceramic coated layer.
Corrosion can also occur due to aggressive cleaning agents, extreme pH levels, or using excessively hard brushes that damage the ceramic coating. Any exposed base metal, whether from dents/damage, inconsistent manufacturing/coating, or aggressive cleaning, can lead to corrosion.
Roll Inconsistency
A top-performing anilox roll must be perfectly balanced and level, with uniform weight across the entire length. Roll inconsistencies can arise from poor manufacturing, uneven wear overtime, and improper handling. Unbalanced and inconsistent rolls can bounce in the machine and damage the ink system, the press, and/or the final print.
The consistency and uniformity of engraved anilox cells are crucial for print success. Anilox cells engraved too deep, wide, or not uniformly can cause ink laydown and color matching issues.
Choosing a precise and diligent anilox partner is crucial.
Roll Chips & Cracks
Chipping and cracking of the anilox roll or sleeve usually result from operator mishandling. Dropping the rolls or improper installation can compromise print quality, increase downtime, and require costly repairs or replacements. Setting up a clear quality control process detailing anilox handling and care can reduce defects due to mishandling.
Preventing Anilox Damages & Defects
The first step to preventing anilox damage and defects is choosing a quality anilox supplier. Apex International manufactures complete roll and sleeve products in-house, from raw material to the finished product, in accordance with customer expectations and OEM specifications.
We utilize:
- The highest available metallurgy for our roll base.
- Low-porosity, super-dense, non-wetting ceramic coating application.
- An UltraMelt engraving process that creates a melted/fused inner cell wall, requiring no additional sealers or chemical processes.
Apex anilox engravings are crafted with precision, featuring wider, shallower profile geometry for greater ink release and easy cleanup. This reduces the need for over-pressurizing the doctor blade chamber, decreasing the likelihood of anilox scoring and roll damage.
With advanced quality control processes and anilox inspection with Veritas, Apex anilox rolls are designed to withstand continuous printing operations while maintaining precise ink transfer and press optimization.
With Apex International, you receive:
- Rolls meticulously crafted with attention to balance, uniformity, durability, and effectiveness.
- Precision and consistency in engraved cells.
- Quality assurance and a limited warranty, ensuring tight tolerances and resistance to common anilox damages and defects.
Download our Anilox Handling & Care Guide for best practices from Apex.
In the demanding world of flexographic printing, taking preventive measures to maintain the integrity of anilox rolls and choosing a trusted manufacturer like Apex International are critical steps towards achieving optimal printing results and operational efficiency. Contact your Apex representative today to get started.
