New applications for UV flexo printing
The new BLK-U® 2 system opens up new possibilities for UV flexo printing on central cylinder presses.
IST METZ has developed the new BLK-U® 2 UV system to be launched at Drupa 2004 specifically for central-cylinder flexo presses. The system has been developed from the BLK® and BLK-U® systems, which have been successfully installed throughout the graphic arts industry world-wide for many years.
The BLK-U® 2 system can be run either in normal atmospheric conditions or in an inert atmosphere in a closed loop. Production in oxygen-reduced conditions is possible without significant modifications. Operation in oxygen-reduced conditions opens up new application possibilities such as printing of food packaging or heat-sensitive materials such as films, thermal papers, aluminium compounds etc. As a result of the closed loop operation it is not necessary to use cooling air from the production hall. This considerably reduces the contamination of reflectors and lamps. Furthermore, it is not necessary to install any exhaust air ducting. A further advantage is the minimal quantity of inert gas required for operation. UV curing under oxygen-reduced conditions also leads to a noticeable reduction in odour as inks and varnishes containing fewer photoinitiators can be used, respectively the curing properties are even better.
The BLK-U® 2 systems are equipped with slide-in cassettes for the UV lamps and water-cooled URS® cold-mirror reflectors as well as the water-cooled shutters. The design ensures consistent cooling along the whole lamp length. The modular construction allows processing of different substrate widths. Installation can be over the central cylinder or a separate cooling roll or a water-cooled undershielding. As the BLK-U® 2 system does not require a quartz glass screen all of the UV energy reaches the substrate. The UV lamps and reflectors are positioned at exactly the correct distance from the substrate to ensure more effective use of the UV energy. The lamp output can be steplessly controlled by the SLC or ELC® control system.
The system is also easy to maintain. For example, the slide-in cassette is simple to remove from the lamp unit. The water, electricity and compressed air supplies all have plug-in connections. The UV system is also designed for use with the latest FLC® (Fast Lamp Change) lamps, which reduce lamp changes to a matter of seconds.
