Rako Etiketten installs Rotalen laser engraver

European label converter RAKO Etiketten has installed a direct laser engraving system for high-volume imaging of screen cylinders at its Witzhave (near Hamburg, Germany) works.

In the short time since production began, the company ‘is already benefiting from improved productivity, zero defects, perfect reproduction and improved quality brought by the engraver’s simplified, eco-friendly and film-free workflow’, according to a statement.

The installation will enable the company to image rotary screens with greater speed and efficiency, while reducing production costs significantly.

Due to the sheer volume of screens used by the company, RAKO chose the rotaLEN 5511 laser engraver, which is dedicated to imaging Stork’s nickel RotaMesh screens in a totally digital manner, free of film and chemicals.

Thanks to the installation, the company says it has been able to significantly boost productivity in the pre-press room. The laser engraver uses a simple, eco-friendly imaging process that involves the thermal decomposition of the positive area of the emulsion, leaving behind the stencil’s open areas. This replaces the lengthy exposure, washing and drying processes needed when imaging the screens in the conventional way and eliminates the use of film, chemicals and UV light.

The overall process is much faster, as Mr Stefan Behrens (pictured), pre-press manager at RAKO Etiketten explained: ‘With rotaLEN, screens are engraved on average in between 15 and 20 minutes, significantly less than the 90 minutes needed with the exposure process. We can maintain fast turnarounds in a hectic pre-press room, where sometimes, up to 40 screens can be needed in a single day.’

Furthermore, rotaLEN has delivered total quality consistency – in the first month of production, no defects have occurred on any of the 400 screen cylinder designs that have passed under the engraver’s beam. ‘This is a great improvement compared with conventional exposure, when some five to eight per cent of screens would have to be reimaged due to a defect,’ said Mr Behrens. 

The fully digital process has ensured all labels subsequently printed by laser engraved screens are identical within a particular print-run – enabling the company to better meet the exacting needs of international brand owners looking to achieve no differences in look and feel for their packaging.  With Stork’s bestIMAGE software, the same design can be re-engraved accurately to the very last pixel.

Improved quality was also noted. The laser beam’s intense focus achieves precise positive and negative structures and very high contrast, ideal for reproducing clear, small text and fine linework. High quality rasterwork is also possible thanks to the laser’s ability to engrave at a wider range of angles than is possible by UV light.

The demand for screen printed designs has increased sharply at RAKO, due to the need for ever higher quality packaging combined with shorter print runs due to the trend towards greater brand variations.

As a result, the number of screen designs printed a year has shot up from 3,700 in 2003 to 12,000 expected in 2006. Extra demand for more innovative designs comes from cosmetics customers, for sophisticated features, like tactile varnish effects, marketed under the company’s High & Clear brand-name. Due to this near-exponential growth, the company specifically opted for a screen-only system, as opposed to Stork’s Helios 6010, which engraves plates and sleeves for all relief processes (flexo, letterpress and dry-offset) as well as nickel screen cylinders.

Given the benefits, the RAKO team is convinced that direct laser engraving represents the future for pre-production. ‘Stork’s rotaLEN is the perfect solution for extremely high volume screen cylinder imaging: it delivers top-class, defect-free quality, total consistency, and a simplified workflow, relieving the scheduling pressure at our pre-production stage. Needless to say, we are delighted with the installation,’ said Mr Behrens.