In flexography printing (abbreviated to flexo) the plate cylinder is covered with a cliché. This is the image carrier and contains all the text or images which eventually get printed on the substrate. The cliché contains raised printing surfaces which prints the ink on the substrate. So all the raised surfaces on a cliché make the image of the run.
Basically, a full printing press machine consists out of several printing towers; each tower containing 1 colour. Before the printing process can begin, the image carrier needs to be prepared. In flexography this is done by making a cliché plate. Every printing tower requires a specific cliché for the placement of that specific color on the substrate. Once all the clichés have been prepared and installed on the plate cylinders; the ink pans have to be filled up.
Ink types for printing techniques are different in their composition but also in chemical-, physical- and printing-characteristics. It’s important to choose the right ink type for the desired result.
The ink pan is filled up, and the machine gets started up. The substrate starts off as a roll in an unwinder; the function of the unwinder is to unroll the substrate and start moving it through the printing towers.
Every printing tower contains a fountain roll, which rotates through the ink in the ink pan. This roll picks up the ink and transfers it to another roll; the Anilox roll. The Anilox roll transfers the ink to the plate cylinder which is covered by a cliché. The raised printing surfaces of the cliché pick up the ink and print it on the substrate (e.g. paper) which is running through the printing towers.
The flexography printing process consist of:
- Inking system (ink pan and fountain roll)
- Anilox roll
- Plate cylinder (contains the image carrier)
- Impression cylinder