How thick is the ink in flexo printing? | Keshenglong&Shinko Guide

How Thick is the Ink in Flexo Printing?

Understanding ink thickness in flexographic printing is crucial for achieving optimal print quality. Many printers struggle with achieving consistent results due to variations in ink film thickness. This article clarifies this often-misunderstood aspect of flexo.

Measuring Ink Film Thickness

There's no single correct thickness for flexo ink. The ideal film thickness depends on several factors including:

Substrate: The material being printed (e.g., paper, film, corrugated board) significantly impacts ink absorption and desired coverage.

Ink Type: Water-based, UV-cured, and solvent-based inks have different viscosities and drying characteristics, influencing their final thickness.

Print Design: Areas with solid color blocks require thicker ink films than areas with fine details.

Aniline Dye: The type of aniline dye used within the ink also impacts the final film thickness.

Printing Press: The anilox roll's cell volume and the pressure settings on the press are key determinants of ink lay-down.

Measuring ink film thickness is typically done using a wet film thickness gauge or, less precisely, by visually assessing the print. Micrometers can also be used for more precise measurements. The goal is consistency—a uniform ink film across the print run.

Achieving Consistent Ink Film Thickness

Several factors contribute to consistent ink thickness:

Anilox Roll Selection: Choosing the correct anilox roll with the appropriate cell volume and geometry is paramount.

Ink Viscosity: Maintaining the correct ink viscosity through proper mixing and temperature control is essential.

Press Settings: Proper doctor blade pressure and ink metering settings are crucial for controlled ink transfer.

Substrate Preparation: A clean and properly prepared substrate ensures consistent ink adhesion and absorption.

Regular Maintenance: Regular cleaning and maintenance of the printing press minimizes variations in ink transfer.

Troubleshooting Ink Film Thickness Issues

Problems like uneven ink coverage, pinholing, or excessive ink build-up often stem from inconsistencies in ink film thickness. Addressing these issues requires a systematic approach, involving careful analysis of all factors mentioned above.