In the next few days, the sheetfed offset facility of Koenig & Bauer AG (KBA) in Radebeul will be taking up production and shipping of a new generation of sheetfed offset presses for the highly popular medium format market.

All that has remained of the previous Rapida 105, which has enjoyed a worldwide reputation for reliability, flexibility and performance for the past 13 years, is the familiar name. But that already sums up the advance: The new Rapida 105 (max. sheet format 74 x 105 cm) builds upon the same technology platform as its top-of-the-class sister press, the KBA Rapida 106. After completion of the usual beta tests, the new press was officially unveiled at the All in Print China trade show in Shanghai in November. Its predecessor was already especially successful on the growth market China. At the end of November, KBA is also offering an opportunity to see the new Rapida 105 in production at the KBA facility in Radebeul.

Many innovative features of the highly automated and high-speed Rapida 106 are now also to be found in the new Rapida 105. And with even more configuration variants than before, it permits tailored adaptation to an endless diversity of user requirements, from commercial and label printing through to high-quality packaging with inline finishing and the many special applications for which the flexible Rapidas are virtually predestined.

The new Rapida 105 is indisputably on the heels of its high-tech counterpart, the Rapida 106. One expression of this is the maximum production speed of 16,500 sph. Further examples are to be found through the whole press: Mention can be made of the DriveTronic feeder with four dedicated drives for the main and auxiliary pile lift (the latter for non-stop pile changing), the feeder head and the feed table. The shaftless technology demands only a minimum of maintenance, is reliable in production, and runs with universal settings for most typical substrates. The pile lift is furthermore continuous and thus jerk-free. Five monitoring functions watch over the passage of sheets through the infeed, and there are neither manual settings to make nor guide elements to be exchanged when switching between different substrates. All press programs can be started and the feeder and infeed settings can be modified at the touch panel on the first printing unit. Valuable preset functions reduce operator intervention to a minimum. All functions can naturally also be controlled through the ErgoTronic console.

Technology transfer from the Rapida 106

The printing unit design is now identical to that of the Rapida 106. The shallower angle between the cylinders reduces the curvature of sheet travel and permits higher speeds. The multi-Venturi sheet guiding system for marking-free sheet transport, air systems to prevent slapping and doubling as the sheet enters the impression zone and sheet guide elements after impression for normal and heavy board have likewise been taken over from the Rapida 106. All air parameters can be set and saved at the press control console. The grippers match the performance of the high-speed sheet guiding and require no adjustment to accommodate substrate changes. The gripper spacing has also been optimised for compatibility with all typical formats.

Five washing system variants cater for the different needs of individual users. The simplest configuration incorporates blanket and roller washing. Alternatively, dual-purpose systems for blanket and impression cylinder washing (CleanTronic/CleanTronic Impact) can be combined with roller washing. With these systems, it is for the first time possible to realise parallel roller and blanket washing in this press class, and thus a time saving of over 40 per cent compared to consecutive processes. Washing cloth consumption is indicated on the console monitor, allowing roll replacement to be planned in good time. CleanTronic Multi is a washing system specifically for two different washing solvents, permitting fast system switching between conventional and UV inks. CleanTronic UV, finally, incorporates an additional safety function to eliminate the otherwise imperative waiting times in UV production. All washing systems are cloth-based systems. The return piping and waste tanks required for a brush system are thus eliminated, and there is no contaminated solvent and sludge to be collected for disposal. The used washing cloth can simply be included with normal household waste. Further benefits of the CleanTronic systems are the considerable reductions in solvent consumption and VOC emissions.

The inking unit of the Rapida 105 is also new. Dynamic ink regulation provides for extremely fast reaction. Infinitely variable oscillation timing adjustment, ink train separation with impression-off and KBA's characteristic disengaging of unused towers are trademarks of the Rapida 105 inking unit. A special, easy-to-replace ink duct foil simplifies ink removal and cleaning.

Fast job changeovers also with coating

Two systems with different levels of automation are available for plate changing

    With SAPC (Semi Automatic Plate Change), the plate is lowered into the plate clamps by hand. All other process steps then run automatically. Changing thus takes approx. 1 minute per unit.
    With the fully automatic FAPC system, all plates are changed in just under 3 minutes – including register zeroing – irrespective of the length of the press.

Coating is another area in which the Rapida 105 boasts many new possibilities. The coating tower can be equipped with either universal clamping bars (change time approx. 2 to 3 minutes) or automated coating forme changing (change time 1 minute). Here, too, the Rapida 105 shines with the shortest change times in its class. The printing pressure and the lateral, circumferential and diagonal register can be set remotely. The HydrocompTM blade pressure control with two-point support for the chamber, furthermore, guarantees a particularly even coating film – and minimal blade wear. The coating supply and cleaning systems are fully console-integrated and provide for very short cleaning and changeover times. The range of possible applications covers gloss and matt finishes, via protective seals or scented, soft-touch and gentle-touch coatings, through to metal FX, special FX and pearlescent finishes. Double-coating technologies are also possible with the Rapida 105, offering access to a multitude of finishing effects through the combination of conventional and UV coatings.

New delivery, new dryers

The new Rapida 105 incorporates the proven KBA VariDry dryer system. The modules can be assigned flexibly for interdeck or final drying and are perfectly matched to the geometry of the press. The combination of UV interdeck dryers and impression cylinder washing is now also possible. Furthermore, the energy-saving VariDryBLUE system is to become available shortly. This system offers significantly enhanced energy efficiency compared to conventional dryer concepts.

The delivery of the Rapida 105 also rightly bears the label “Rapida 106 inside”. The high-line delivery with multi-Venturi sheet guiding is engineered for maximum production performance. The air nozzle form and layout have been optimised to ensure stable, air-cushioned sheet travel. The gripper carriages display exceptional aerodynamic qualities. The result is flutter- and marking-free sheet transport, and even powder application with minimised consumption. The delivery offers preset capabilities via a touch panel or the ErgoTronic press console.

The control console of the Rapida 105 is based on the Wíndows operating system. The user interface is clear and straightforward – as Rapida users have long since come to expect – and presents extensive screen menus and programs both for the press itself and for linked peripherals. Interfaces are provided, for example, for dryer control, the cooling systems, DensiTronic and LogoTronic. With PressSupport 24 and an integrated Internet connection, the prerequisites are set for remote maintenance and online software updates. Indicator functions draw attention to pending care and maintenance measures.