Gravure is small cells recessed into a cylinder that hold ink. The cylinder is washed with ink; a doctor blade removes the excess, leaving ink only in the cells. The ink is transferred to a substrate (paper, plastic, film, and more) using a rotary press.
Rotogravure, or gravure, is an old process. Building on earlier printing methods, modern gravure began in the late 19th century, and became widespread in the early 20th century. The popularity of the Sunday rotogravure section, which was filled with printed photographs, increased the use of gravure.
Today gravure printing is widely used in:
Cylinder being engraved
Cylinders for gravure have been made in several ways. First came chemical etch, followed by electro-mechanical (diamond cutting) and then laser etching. The latter two use digital images and controls.
Gravure cylinders are extremely long-lasting. They are made of steel, coated in copper for engraving, then finished with chrome. When the cylinder is no longer needed, the chrome and copper can be removed and the steel base reused.
Because of the stable steel bases, gravure cylinders can be quite large. Some publication presses run 3 meter (9.84 feet) wide cylinders. Cylinders can also be extremely small: 16 inches wide or even less. Cylinder diameters can also vary from very small (2.5 inches or 64 mm) to very large (40 inches or 1,016 mm).
Extremely large engraver. This specialty machine is used to engrave laminates.
Each printing process has its strengths. Gravure has many:
"Gravure has fewer variables to control than other printing processes, ensuring more consistent print quality throughout a run." ("Gravure Process and Technology" 5)
Gravure provides "consistent color throughout a press run, even when that run consists of several million copies." ("Gravure Process and Technology" 7)
Gravure is a direct printing process: the image on the cylinder is printed directly to the substrate. This results in better ink laydown and thus a more faithful image rendering.
Image data wrapped around the cylinder can be continuous, so no plate seam shows, such as in wall paper or gift wrap.
Gravure printing routinely uses a wide variety of substrates:
For more information, please visit PIONEER.
The depth and size of engraved cells determines the amount of ink that can be put on the substrate. Gravure printing can lay down more ink than other processes.
Gravure presses run at high production speeds: - feet per minute.
Cylinders are extremely durable. Print runs of 2 million to 3 million from one cylinder set are common.
The diamond cutting tool (the engrave head) can cut at speeds of up to 10,000 cells per second. Special applications use cutting speeds much lower, such as cps or even lower.
For more information on Gravure, we recommend contacting GAA, the Gravure Association of the Americas
Since , Ohio Gravure Technologies has been a leader in designing machines for gravure. Constant innovation in hardware and software has resulted in sophisticated tools for the gravure printing industry. For more information about how our highly accurate gravure solutions can help with your application, please contact us.
"Rotogravure." Wikipedia, The Free Encyclopedia. 29 Nov , 22:24 UTC. 9 Dec
Gravure Process and Technology. Versailles, KY: Gravure Education Foundation and Gravaure Association of America, . Print
February , 28
4 comment
Rotogravure is the premier, cost effective printing method for higher volume, high resolution packaging and displays. The principles of rotogravure printing underlines the fact that image areas are in a sunken area and the non-image areas are in relief that is why this is also known as intaglio printing. One of the most important feature of the gravure printing is the steel cylinder that is used as an image carrier. Gravure cylinders are usually made of steel and plated with the copper and then images are engraved on this cylinder by chemical etching or with a diamond tool and laser beam.
In general gravure cylinders are plated in chrome as a protective surface for the cells formed into the copper plated surface. These cells on the cylinder control the amount of the ink transfer on the substrate. In order to achieve more intensity of color on to the substrate deeper cells are required and smaller cells produces less ink density of color. The handling of chrome plating requires strict control, however so there has been a strong demand in the gravure cylinder making industry for a hard replacement material. The basic steps involve in the cylinder engraving are as follows;
The process control is very important during electromechanical engraving of gravure cylinders many problems arise like pin holes, stylus broken, shoe lines, cell depth variation, cell missing, thundering, centre out, pin holes, bludges, machine hang out. Patches, improper dots and depth variation and all these should be removed. The engraved cylinders has five major specification stylus, angle, that accuracy in also inevitable during the cylinder engraving and variation in these specification cause the various defects during the printing process. Engraved cylinder handling and storage is also very critical for the printer to maintain quality perfection and long lasting for optimum performance. The cylinder should be stored in racks to use for future jobs, automatically transported from one step to the next-from imaging to the press room and back to storage and during make ready, the press operator carefully loads the printing cylinders into the press.
Muhammad Sajid Khan
If you are looking for more details, kindly visit Gravure Cylinder Making Machine.