Printing Operations

In a modern flexo printing press, each print unit comprises of:
Anilox roller: a cylinder of highly engineered metal and/or ceramic, which is laser engraved with minute cells of a given angle, line screen, and volume to deliver the required fineness of print
Chambered doctor blade system:  a device that delivers a measured amount of ink to the cells of the anilox roller
Rubber rolls: an alternative system to the chambered doctor blade, consisting of two rubber rolls in contact with each other. One roll sits in an ink bath and transfers the ink to the second which is in contact with the anilox roll. A negative blade may be added to the anilox roll to limit ink flow
Plate cylinder: which the printing plate is mounted upon
Impression cylinder: a sleeve that supports the substrate as the printing plate is pressed against it
Inking system: ink holding tank, ink pump with delivery and return ink lines, plus other elements to ensure the maintenance of ink supply and viscosity
Between the print units, driers may be installed so that subsequent colors can be applied to the substrate without merging into those previously printed. These driers may utilize hot air, infra red, or ultra-violet light, depending on the application.
During the printing process, the ink is pumped into the ink chamber of the doctor blade system. Two blades within the ink chamber, the barrier blade and the doctor blade, seal either end and confine the ink to the chamber while it is in contact with the anilox roller. As the anilox roller rotates, the cells in contact with the doctor blade system collect ink, and then any surface excess is removed as the roller passes under the doctor blade. As the anilox rotates, its surface comes into contact with the raised areas of the printing plates mounted on the plate cylinder, transferring the ink. The printing plate then rotates and transfers the image onto the substrate.