Gravure Printing - Rotogravure Printing Information
 Rotogravure
printing is a printing process that involves engraving the image onto a copper
cylinder, like offset and flexography; it uses a rotary printing press. Gravure
printing is characteristically used for long run, high
quality printing producing a sharp, fine image. It is most often used for very
long runs of up to a million or more.
A rotogravure printing press has one printing unit for each color. There are
five basic components in each color unit: an engraved, an ink fountain, a doctor
blade, an impression roller, and a dryer. While the press is in operation, the
engraved cylinder is partially immersed in the ink fountain, filling the
recessed cells. As the cylinder rotates, it draws ink out of the fountain with
it. Acting as a squeegee, the doctor blade scrapes the cylinder before it makes
contact with the paper, removing ink from the non-printing areas.
Next, the paper gets sandwiched between the impression
roller and the gravure cylinder. This is where the ink gets transferred from the
recessed cells to the paper. The purpose of the impression roller is to apply
force, pressing the paper onto the gravure cylinder, ensuring even and maximum
coverage of the ink. Then the paper goes through a dryer because it must be
completely dry before going through the next color unit and absorbing another
coat of ink.
|
