Rotogravure printing originated in the early
nineteenth century. Rotogravure printing allowed the newspaper industry to
reproduce photographs and art work on a mass scale on inexpensive newsprint
paper.
The technology adopted by newspapers is more
precisely called rotogravure. Unlike the letterpress, which uses raised or
relief printing, rotogravure uses intaglio printing, in which metal is etched with
recessed "cells" to hold the ink. The process was first used in art
reproduction because of its high quality tonal gradation and color depth. From
this process evolved photogravure—rotogravure printing where a plate is etched from
a photographic image
Rotogravure printing is so consistent that color
variations are rare, ink does not smear, and pages can be handled (and bundled
for shipping) immediately. Newly equipped newspapers were able to print large
pictorial sections that increased readership and advertising revenue. Rotogravure
printing is characteristically used for long run, high quality printing
producing a sharp, fine image. The
rotogravure process is still used for commercial printing of magazines,
postcards, and cardboard product packaging.
Features
- Extremely stable
- Excellent bond strength
- High color depth
- High gloss
- Brilliant brightness
- Excellent
- Skin friendly
Rotogravure Inks - Solvent Based, Water Based
The solvent-laden air from the dryers is passed through either a solvent recovery system or solvent vapor incinerator. A typical recovery system uses beds of activated carbon to absorb the solvent. Saturated beds are regenerated by steam. The solvent laden steam is then condensed and the water and solvent separate by gravity. Greater than 95 percent of the ink solvents can be recovered using this process (Buonicore). The solvents can either be reused or destroyed by incineration.
Water
based inks, especially used for packaging and product rotogravure, require a higher
temperature and longer drier exposure time in order to drive off the water and
lower vapor pressure constituents. As mentioned subsequent sections, Flexo and Rotogravure inks are very similar and the constituents are essentially the same.
Again, a pollution control device may be needed.
The major unit operations in a rotogravure printing operation are- Image preparation
- Cylinder preparation
- Printing
- Finishing
Applications
Typical rotogravure printed products include
- Food packaging
- Wall paper
- Wrapping paper
- Furniture laminates
- Paneling
- Greeting cards
- Magazine
