In the flexographic printing process, it is essential that the ink is delivered to the printing plate in a precise manner. This is accomplished by using a specialized part known as an anilox roller. This is an integral part of any printing process and should not be chosen at random. There are varying properties of an anilox roller and selecting the right one will depend on what is being printed and other application specifics.
Anilox rollers are hard cylinders usually made of metal or ceramic-coated metal. Their surface is not completely smooth. Instead, it is engraved with tiny cells in a uniform pattern. These cells are what allow the printing ink to be delivered at a consistent volume. Doctor blades remove the excess ink from the roller and allow the cells to provide a precise amount.
Understanding Line Screen
Line screen or line count is one way to specify the properties of an anilox roll. It has a direct correlation to volume. It basically defines the number of cells per linear inch across the surface of the roller. Low line screen rolls will not be capable of providing the quality needed in some applications. Conversely, a high line count will not be able to deliver enough ink for other jobs.
Anilox rolls should always be cleaned and maintained properly. It is critical to do this immediately after use, especially when using water and oil based inks. Anilox cleaners contain chemicals that are formulated to easily remove dried ink from engraved surfaces. If this is not done then defects can occur during subsequent print jobs.
Anilox rollers are precision manufactured to meet the needs of your printing process. In order to perform at their best the right one needs to be chosen for each print job, and they also need to be cleaned properly.