Koenig & Bauer ‘Sprinting Ahead’ at Drupa with Offset and Digital Print Innovations

KBA RotaJET 76: digital print from the offset experts

The round of innovation previews began with a high-volume web-fed inkjet press of the latest generation for the on-demand or individualized production of four-color books, brochures, commercial products, mailings and magazines. The KBA RotaJET 76, built at KBA in Würzburg, was presented by new Project Manager Oliver Baar, an experienced specialist in the field of digital print.

Engineered for a maximum web speed of 493 fpm and web widths of up to 30.7˝(corresponding to approx. 3,000 A4 pages/min or 85 million pages per month), the KBA RotaJET prints with water-based pigment inks. The state-of-the-art piezo inkjet heads are reliable in production and require only a minimum of maintenance. They have been designed for heavy-duty use and contribute to the high availability of the overall system. Frequent replacement is avoided and uninterrupted industrial production is guaranteed.

Precision engineering from KBA is the key to high print and register quality with the inkjet technology. This quality is only realized, however, in combination with precise web tension. The unwinder and infeed unit have thus been designed specifically for the RotaJET. Together with an ingeniously simple web lead without turning bars for four-color production, they ensure excellent results.

Web tension is controlled fully automatically. In this connection, Baar pointed out the greatly reduced waste compared to other press systems, as the RotaJET 76 is thus able to produce good copies even during the start-up phase. This permits considerably more efficient production and at the same time enhanced flexibility. An automatic reel stand with integration into automated paper logistics is to be made available in future as an option to further boost productivity. The web offset expertise is unmistakable.

The two arrays of 56 inkjet heads each (total 112) form an arch over large central impression cylinders for four-color printing on both sides of the web, but can still be shifted aside for cleaning and maintenance purposes. This arrangement provides for optimum web guidance and facilitates an outstanding print quality even with problematic materials. The printing heads are cleaned and aligned automatically (stitching) to minimize manual intervention and ensure straightforward handling.