In everyday life, the word “volume” is used for the amount of space that is enclosed in a container. For example, a one-liter bottle has a volume of one liter, or 1,000 cubic centimeters (cm3). A one-gallon container has a volume of 231 cubic inches (in3) and would contain 3.7584 liters. They’re both volumes, one is just bigger than the other.
Anilox volume is slightly different, but related. It’s simply the total volume of all the tiny, laser-engraved cells on its surface per unit area of the surface. And there are two anilox volume units in use here on Planet Earth and which one you use depends on where you are.
In the United States, Canada, and Mexico where imperial units are still common, we use “bcm”, which stands for billions of cubic microns per square inch. Everywhere else where the metric system reigns supreme, we use cubic centimeters per square meter (cm3/m2), sometimes referring to that unit as just “CCs”.
One cubic centimeter of ink covers an area one meter on a side with a layer of ink one micron thick. One billion cubic microns of ink covers one square inch with a layer 1.55 microns thick (61 millionths of an inch). You can probably see why most of the world prefers using metric volume units!
To convert from cm3/m2 to bcm, divide the cm3/m2 value by 1.55. To convert from bcm to cm3/m2, multiply the bcm value by 1.55.
cm3/m2 = bcm x 1.55
A 1 cm3/m2 anilox would have an imperial volume of 0.645 bcm, while a 1 bcm anilox would have a metric volume of 1.55 cm3/m2. This is why the volume value always looks lower in imperial units than in metric units. Volume is volume and these two are different only by a factor of 1.55. As the figure shows, the cells of a 1 bcm anilox would be filled about two thirds of the way up with 1 cm3/m2 of ink.
Notice how this is going: a 1 cm3/m2 anilox can carry the equivalent of a 1 μm thick layer, a 2 cm3/m2 can carry a 2 μm thick layer, and so on. For bcm it’s not as easy. One bcm is equivalent to a 1.55 μm thick layer, 2 bcm is a 3.1 μm thick layer, etc., so the math isn’t as convenient, but the principle is the same. The doctor blade makes these ink layers conform to the anilox cell matrix. We’ll cover how much of that ink gets released in another blog post. Spoiler alert: not all of it is released and how much depends on the cell shape.
Anilox volume is an extremely useful parameter because it can be accurately measured, allowing printers to precisely monitor anilox condition and compensate for inevitable wear. Measuring a cylinder’s volume with the high speed MicroDynamics Veritas™ anilox inspection system after each cleaning eliminates the uncertainty of how the cylinder will perform on the next run, reducing waste, improving print quality, and creating happy customers that come back again and again. Contact a MicroDynamics sales associate for more information or learn more about the Veritas microscope on our website.
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