ROTOGRAVURE, the second rotary printing process.
Rotogravure is similar to offset litho in that the image plate is wrapped around a cylinder.
However the plate itself is made from copper and etched in a different way (intaglio), it has a deeper etch, which makes it more expensive but it is this that gives it greater durability. Higher durability lends itself to have a longer print run or for use on tougher substrates (the material printed on).
The process of rotogravure is often referred to as "gravure" for abbreviation.
A rotogravure press includes an ink fountain engraved cylinder, a doctor blade, a dryer, and an impression roller. The engraved ink fountain cylinder is versatile enough to be changed to meet the requirements of each job layout. Generally, these changes are made by adjusting its circumference.
A printing job on a rotogravure commences when the cylinder is dipped into the ink. As it is immersed, the cells of the cylinder become filled with ink. Each rotational movement of the engraved cylinder causes it to become filled with more ink.
Next, the material to be printed on is placed between the engraved cylinder and the impression roller. In this way, the ink from the cell is transferred to the material. The final process is for the material and the newly applied ink to pass through a drying method. The drying process prepares the material to receive another colour of ink. Each colour on a rotogravure press has its own printing unit, still using CMYK just like Offset Lithography.
Gravure cylinders nowadays are typically engraved digitally by a diamond tipped or laser etching machine. On the gravure cylinder, the engraved image is composed of small dots, that act as tiny wells, which creates a denser ink coverage. Their depth and size control the amount of ink that is transferred to the substrate (paper or other material, such as plastic or foil).
Gravure is an industrial printing process mainly used for the high-speed production of large print magazines and newspapers and runs at a constant and top quality. Other uses for the gravure process are in wallpaper and laminates for furniture where quality and consistency are desired.
Gravure is an industrial printing process mainly used for the high-speed production of large print magazines and newspapers and runs at a constant and top quality. Other uses for the gravure process are in wallpaper and laminates for furniture where quality and consistency are desired.
No comments:
Post a Comment