Flexography, a versatile printing process, relies on specialized inks to achieve high-quality results.
Unlike traditional letterpress printing, which uses slow-drying inks, flexography employs fast-drying inks with unique properties.
In this article, we'll explore the critical differences between flexo inks and letterpress inks, and discuss six essential tests that every flexographer should be familiar with to ensure consistent printing performance.
Ink Color and Strength
The initial part of the drawdown simulates the solid print that will be achieved on the press, while the lighter portion reveals undertones and shade differences.
Drying Time
Water-reducible inks, on the other hand, rely more on penetration than evaporation for drying.
A drawdown test on the actual substrate helps assess drying rates.
Solids Content
This information aids pressmen in adjusting ink formulations as needed for optimal results.
Fineness of Grind
Weight per Gallon
This information can be used to calculate specific gravity, a vital factor in ink formulation.
Viscosity
Viscosity measurements are recorded with the cup type and temperature to ensure consistency.
Conclusion In the world of flexographic printing, understanding and testing ink properties are essential for achieving consistent and high-quality results.
By performing these six simple tests, pressmen can ensure uniformity of performance and printing results, avoid costly mistakes, and maintain control over the ink composition.
As the demands of flexographic printing evolve, incorporating these tests into standard practices becomes increasingly important to meet the challenges of complex substrates and color-process jobs.