Fischer & Krecke (part of the Bobst group) has announced the commercial launch of its smartGPS system (Graphic Positioning System) for the flexo printing industry during January 2009. The system is a revolutionary new concept in the registration and impression setting up of a flexo press between job changes. The beta version of this system, which was first exhibited at drupa 2008 had created quite a stir. Since then, it has been extensively tested at both customer sites and at the Fischer & Krecke plant and has now been released for commercial production.
The most crucial and time-consuming operations during the change-over from one job to another on a flexo press are registration of colours and impression setting of the flexo plate to get the best print reproduction. Once this is achieved, the press is cranked up to full speed and the new job is printed. The process also accounts for the bulk of material wastage generated during the set-up stage as it is done on-press. Traditionally, the registration set-up is based on an automatic optical system whereas the impression setting is a manual adjustment that requires considerable skill and experience. The advantage of the smartGPS system is that these settings can be done off-line at the plate mounting stage with almost no additional time required.
The technology uses a standard plate mounter from JM Heaford and a specially developed measuring system that is integrated into it. This enables the print-ready cylinders to be scanned to an extremely high degree of precision, Sensors ensure the correct positioning of the whole package of carbon fibre cylinder, sleeve, tape and printing plates. An RFID antenna transmits the specially calculated data to a chip embedded in the sleeve. Complex software has been developed by Fischer & Krecke that includes all parameters starting from each module of the package (adapter, sleeve, adhesive tape and plate) to the material type used in the machine to automatically calculate the optimum impression values. The whole process takes only a few seconds during the off-line mounting stage. The reading of the data to the machine control system and the forward racking of the print units is fully automated and synchronised for all the print units involved in the job. According to Fischer & Krecke, once the print units have moved to the off-impression position, it takes only a mouse click and a pressing of the start button to produce saleable product from the first impression. No substrate is wasted for setting up and the time saved in doing so also generates savings. This system is particularly useful for short runs and more frequent change-overs as it cuts down on wastage and non-productive set-up times and provides more printing uptime. It also eliminates the manual and subjective skill element from impression setting and provides for process standardisation.
Another problem that automatic and accurate impression setting overcomes is that modern fast drying inks do not begin to dry correctly until the press reaches a reasonable printing speed that delivers a dwell time of the ink on the plate that is short enough to prevent premature drying of the ink. This takes time during setting up and generates a lot of wastage in the process. Incorrect drying leads to mistakes in the impression setting which need to be corrected when the press speed picks up. With smartGPS technology, these settings are pre-calculated and known at the mounting stage itself before the job enters the press and the press can be immediately accelerated to optimum speeds.
Yet another benefit is that reproducibility during repeat print runs is assured since the data are precisely calculated and stored and quality is not dependent on manual adjustments or settings. It also eliminates the possibility of plate damage due to high impression settings. The smartGPS system works equally well with coatings and lacquers that do not have a contrast with the background substrate to enable accurate manual impression settings.
According to Fischer & Krecke, more than a dozen machines in the FP series equipped with smartGPS are ready for delivery and they will soon be offering retrofit kits for existing equipment. Ralph Schuck, Managing Director of F & K and Head of the Bobst Group Product Line Flexo, had this to say, “smartGPS has passed the toughest tests with flying colours. Even with the most demanding print jobs which printers had given us, the system provided convincing evidence for its extraordinary capacity. The immense demand for smartGPS leaves us in no doubt that this new technology will become the flexo industry standard in the near future.”