Rapida 185 / 205

The AC drives function without the previously indispensable mechanical link to the drive of the press itself. They ensure a constant pile height relative to the feeder head with no differences due to stepping intervals.  

The pile lift, at the same time, is much smoother - also at the point of pile reunion in both standard and fully automatic non-stop operation. Numerous components prone to wear, such as timing gears, cardan shafts, belt drives, etc., are rendered superfluous. 

The infeed maintains the widely proven principle of a swing arm operating from below, combined with timed pneumatic and mechanical sheet guiding elements for reliable and scratch-free feeding of the sheets to the feed drum. 

The ink keys of the Colortronic ink ducts each cover a 30 mm zone. The tips of these ink keys are carbide blades. In combination with the ceramic-coated duct roller, they ensure that the whole metering system is able to operate free of wear.  

The function principle of the ink keys guarantees exact, bleed-free separation of the individual zones and renders equalisation software superfluous. The fact that the duct roller is driven synchronously with the press provides for a fast ink transfer from the metering point to the vibrator roller. 

Requested ink metering corrections are realised quickly and without fluctuation. The special locking mechanism at the ink duct ensures that it is always closed to the duct roller with uniform pressure and contributes similarly to a high degree of reproducibility. 

The varnish plate is inserted in the direction of printing. With semi-automatic plate clamping, this eliminates the previously necessary manual tightening of the tensioning screws. 

The makeready time for the semi-automatic system has thus been reduced to just a couple of minutes. 

The anilox roller is 355 mm in diameter. The advantage of such a torsionally rigid roller is a more even varnish application across the whole sheet width. Each coating tower is fitted with a hoist to facilitate exchanging of the anilox rollers. The rollers can be placed on a special rest on the top of the coating tower, or else lowered into a transport box on the floor by slewing the hoist beam. 

The LithoCoat system brings a number of decisive design changes and significant benefits with regard to ease of operation and quality. With this system, the blade chamber is applied to the anilox roller and automatically compensated by way of a hydro-pneumatic blade pressure control feature. The extremely low contact pressure ensures a considerably longer service life of both the blade and the anilox roller. 

The positioning of the blade chamber against the anilox roller is a linear action. This means that the angle of the blade and consequently also the volume of varnish applied is always constant. With six actuating cylinders distributed evenly across the whole width of the chamber, possible flexing of the chamber can be prevented effectively. 

For maintenance and cleaning purposes the blade chamber can be swung out by 90° for removal, without the need for tools. The surfaces of the chamber itself have been given a special coating known as "Ceramic Coat", which provides for simple cleaning. 

To reduce setting up times, the coating tower can be combined with an optional varnish supply and cleaning system, the so-called LithoCoat Circulator. This system can be used for both water-based and UV varnishes, and includes a warm water tank and a recirculation tank for the cleaning solution. The need for additional manual cleaning is practically eliminated. The printer operates the system simply and conveniently by selecting different programs via a touchscreen controller. 

Precise sheet travel is achieved by a large radius of curvature and adjustable air cushions. Pile accuracy is supported by a combination of fans and blower pipes and by speed-compensated adjustment of the gripper opening cam. All fan settings are stored on the console computer and can be recalled for repeat jobs. The optimised aerodynamic design of the gripper carriages serves to reduce turbulence to a minimum. 

Despite the aerodynamic design of the gripper carriages, VOCs, odours, heat and powder dust are nevertheless transported in their wake.  

The situation is exacerbated if the sheets are coated, as drying releases odorous substances which, though not hazardous to health, are still far from pleasant for the press operator. The ACS system was developed as an option to reduce VOC levels. An ACS delivery features a main extraction facility with an acrylic baffle under the viewing window in front of the delivery pile, and additional extraction ducts at the pile edges. 

In conjunction with the Impact washing system, blanket and roller washing can now be performed simultaneously. Cloth replacement is very simple and can be handled by a single operator. A further benefit of this system is the precisely controlled fabric advance by way of an electric motor, which provides for more effective utilisation of the cloth. The length of cloth used is measured during the winding onto the permanent spindle in the washing beam. The printer is informed as to the remaining cloth length and the corresponding number of washing cycles via the console monitor and can prepare the imminent replacement in good time. 

All Rapida 185/205 presses incorporate the fully automatic plate changing system APC as a standard feature, and are thus able to achieve plate changing times which have in the past only been known from smaller format classes. When they reach this size, the plates naturally call for a different form of handling. For this reason, the operator is offered an optional lifting facility for loading and unloading of the plate holders on the tower guards. 

The Rapida presses are equipped with single holders rather than plate cassettes, so as not to place unnecessary limitations on flexibility. The new plates can already be placed in the holders in advance. The actual change process is then activated from the control console, whereby the first step of the process is automatic zeroing of the register settings in the selected printing units. To enable manual register corrections - which are by no means unusual on sheets of this size - the rear clamping bars are split into three sections. APC changes the plates in four cycles, taking just 3 minutes to do so - irrespective of the number of printing units involved. 

ACR Control comprises a camera, an integrated PC and the corresponding software. The camera is used to determine any register differences, and calculated correction values are then transmitted to the lateral, circumferential and diagonal register systems on the individual printing units. 

To be able to make proper use of the automatic function, it is necessary to overlay a special measuring patch when exposing the plates. In view of the required precision, the measuring patch can only be incorporated effectively using a CtF or CtP system. With its 50x magnification, the camera can also be used to inspect freely selected areas of the image.