World Debut of MAN Directdrive At Drupa 2004

What MAN Roland believes to be a trailblazing technical innovation will open up new savings potentials on sheetfed presses.

What MAN Roland believes to be a trailblazing technical innovation will open up new savings potentials on sheetfed presses.

Directdrive a new drive system for the plate cylinder realises parallel plate change on all printing units at the same time.

During the plate-changing operation, wash-up can also take place.

The new technology will have its world premiere at Drupa 2004 in May.

The direct-drive principle, known from use in commercial and newspaper web-fed presses, now modified for sheetfed machines, will be demonstrated on a printing unit of the Roland 700.

On a Roland 700 equipped with the APL automatic plate-changing system, all plates are changed in the time it normally takes to change just one, claimed MAN Roland.

The flying plate change familiar on web presses is now also possible in sheetfed with the system.

Because wash-up can take place at the same time it reduces the time for plate change or job changeover to just a few minutes - even on long perfectors with eight, 10 or 12 colours, said the company.

Text changes on a six-colour press, for example, can be carried out without long interruptions.

For instance, while the black plate for language version "X" may be running in the fifth printing unit, the black plate for the new version "Y" can be loaded in the sixth printing unit.

The decoupling of printing-forme change and production creates the potential for a press with integrated Dico imaging technology to have printing formes for different versions changed while the press is running and without plate change.

To create advantages like de-coupled or parallel make-ready operations and precision drive to sheetfed offset required a different approach from those used in web offset, said MAN Roland.

In sheetfed, the combined feed of force from the drive motor via a longitudinal shaft and gearing continues to offer many advantages, especially with long perfectors.

Besides, many transfer elements of the sheet guiding system are in constant mechanical contact.

Malfunctions of different drives, which on web presses cause web breaks, would immediately result in mechanical destruction on sheetfed presses.

So, for sheetfed presses the direct drive is confined to the plate cylinder.

It is mechanically de-coupled and directly driven by a high-torque motor mounted on the cylinder journal.

A 360-degree circumferential register further makes the Roland 700 variable for using different plates from presses of other makes, differing in image start.

Because the system provides exact control other benefits were created.

For instance, the plate cylinder precisely maintains its position at least as well as it would with mechanical gear drive, although the company's tests have proven it to be better, with a deviation tolerance of less than 10 thousandths of a millimetre.

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