What Is an Anilox Roller?
The anilox roller is a precision-engraved cylinder that meters a precise, consistent volume of ink from the ink pan or chamber to the printing plate. It is the fundamental ink-control element in every flexographic press. The doctor blade wipes excess ink from the roller surface, leaving only ink held in the engraved cells, which then transfers to the printing plate and subsequently to the substrate.
Key Anilox Specifications Explained
Line Screen (LPI — Lines Per Inch)
LPI refers to how many cells are engraved per linear inch. Higher LPI = more, smaller cells.
- Low LPI (100–200): Heavy ink deposits, coatings, varnishes
- Mid LPI (300–500): Standard packaging, spot colors, solid areas
- High LPI (700–1200): Process printing, fine halftones, high-resolution graphics
Rule of thumb: Anilox LPI should be 4–6× the halftone ruling of the plate.
Cell Volume (BCM — Billion Cubic Microns per Square Inch)
BCM measures how much ink each square inch of anilox surface can hold.
- Low BCM (1–3): Thin ink films for fine detail and process color
- Mid BCM (3–8): General packaging, strong spot colors
- High BCM (8–20+): Heavy coatings, white ink on film
Selecting the Right Anilox for Each Job
| Application | Recommended LPI | Recommended BCM |
|---|---|---|
| Process color (CMYK) | 700–1000 | 1.5–3.5 |
| Spot colors, solids | 400–600 | 4–8 |
| White ink on film | 200–400 | 8–16 |
| UV coating / varnish | 150–300 | 10–20 |
Anilox Cleaning: The Single Biggest Maintenance Variable
A clogged anilox cell cannot release ink consistently. Even a partial clog of 10–15% of cells produces visible density loss, banding, and color variation. Three cleaning methods exist:
- Manual cleaning: Appropriate for immediate job-change cleanup and light residue removal.
- Ultrasonic cleaning: Recommended for weekly deep cleaning — removes dried ink that manual brushing cannot reach.
- Laser cleaning: Most thorough. Vaporizes dried ink without abrasion. Best for severely clogged rollers.
Anilox Wear and Volume Loss Over Time
Ceramic anilox surfaces wear with use. A roller that began at 6.0 BCM may measure 4.5 BCM after 12–18 months of heavy production. Periodic anilox volume verification using profilometry is essential for maintaining color consistency across months of production.
LISHG presses are designed to accommodate anilox rollers from all major suppliers. Contact our technical team for anilox selection recommendations based on your specific substrate and ink system.
