How Is a Press Made?
High-precision series production - the Heidelberg production
network at Amstetten, Brandenburg, and Wiesloch-Walldorf. Offset
printing systems are like gigantic mechanical and electronic
clockwork mechanisms consisting of 100,000 parts with accuracy
requirements down to one thousandth of a millimeter.
Printed matter provides information and communication and is
an everyday medium enhancing education and quality of life. This
can take the form of a car brochure, mineral water label, picture
book, encyclopedia or packaging for cornflakes, creams, etc. On
each working day, around 60 billion A4 pages - excluding newspapers
- are printed throughout the world.
Over 70 percent of all the world's printed matter is
produced in offset. Offset is the most advanced printing process in
quality and production terms and the most cost-effective for runs
from approx. 500 to more than 500,000 copies. The market volume for
presses in the print media industry is just under five billion Euro
in sheetfed offset and around one billion Euro in commercial web
offset. Heidelberger Druckmaschinen AG is the world market leader
in the sheetfed offset segment, with a share of over 40 percent.
Offset technology, developed around 100 years ago, uses ink
dots on a scale of hundredths of a millimeter consisting of the
primary colors cyan, magenta, yellow, and black that need to be
accurately positioned above and next to each other. However, the
human eye is highly sensitive. If the ink dots are not positioned
exactly in the screen configuration, this is immediately perceived
as a color deviation and fuzziness.
Process colors are applied one after the other in the offset
press. For each color, a printing unit and printing plate are
required, from which the print image is reproduced. The demands
made on the stability and precision of the press to achieve this
are enormous, as the ink dots need to be positioned exactly, even
after the eighth printing unit, at a speed of 15,000 or 18,000
sheets per hour. The fragility of ultra-thin paper and the
bulkiness of card also need to be overcome.
Production tolerances - one thousandth of a millimeter, one
sixtieth of a hair
These precision and quality requirements for operating an
offset press are secondary, however, to the requirements for
developing and constructing such print systems. A Heidelberg press
is a high-tech device consisting of up to 100,000 parts and
components. These are augmented by high-performance software for
controlling up to 600 individual drive axes and up to 300 pneumatic
parts. The cast iron offers stability. Tolerances down to
thousandths of a millimeter - one sixtieth of a human hair - and
the precise interaction of the mechanical and electronic parts
accurate to within a millisecond ensure the precision that is
needed. At the end of a mechanical engineering production process,
up to 50 tons of cast iron and electronics need to work more
precisely than a Swiss watch.