Anilox

[1] An anilox roll is a hard cylinder, usually constructed of a steel or aluminum core which is coated by an industrial ceramic, typically chromium(III) oxide powder, whose surface is engraved with millions of very fine dimples, known as anilox cells.

Depending on the detail of the images to be printed, the press operator will select an anilox roll with a higher or lower line screen.

Higher line screens (500-1500 lpi) produce finer details and are used in four-color process work such as reproducing photographs.

Cell count remains the same for the life of the roll, while volume changes over time due to wear, plugging and damage.

The other reverse angle blade works as previously described, removing excess ink from the engraved surface of the anilox roll.

Chambered doctor blade systems are recognized for high quality, consistency and accuracy removing the influence of press speed and some human subjectivity.

Anilox rolls were originally made using a process of mechanical engraving, utilizing hardened steel tools of various cell counts and cell shapes diamond pecking machine, but modern rolls are laser engraved.

Lower volumes = thinner ink films for the highest quality process printing.

Higher volumes address combination, screens, line work, solid coverage and coating applications.

Limited print stations generally call for a compromise between the highest quality graphics and color.

The only way to convert cm3/m2 (transfer volume) to LPCM (cell finesse) or BCM to LPI is to look at the conversion chart provided by the anilox roll supplier.

Extreme caution must be taken when handling these pieces of hardware as a single bump against a hard surface or sharp corner can destroy the delicate cell structure on the surface and render a roller completely useless, at a cost of around US$5000 for even small narrow-web rollers.

Ceramic Anilox are routinely manufactured by plasma spraying chromium(III) oxide powders (Cr2O3) on to the roller or sleeve surface.

[4] The European Chemical Agency (ECHA) classes sodium dichromate a Substance of Very High Concern (SVHC) [5]