Driving the digital flexo revolution

The project team – representing Adare, Apex, DuPont, Esko, Flint Group Narrow Web, Gidue and UPM Raflatac – has selected UV flexo, extended colour gamut and digital process automation as the technology drivers to support flexography’s transition to ‘digital’ and to maintain its leadership position in the labelling and packaging printing industry.

According to the project’s publicity, the team members are spearheading a move towards what they call ‘flexo digitalisation’ through co-operation and sharing their latest innovations.

As indicated below, each delivers a specific technical contribution.

Comments Niklas Olsson of Flint Group Narrow Web: ‘UV flexo is the ideal process to become digital. UV inks are inherently consistent as there’s no VOC evaporation to “disturb” the printing process. Furthermore, as inks don’t dry on the plates, waste is reduced and consistency increased. Printing quality from UV flexo inks is superior to water- and solvent-based flexo inks as less ink is transferred (ink is full solid, without VOCs); dot gain is reduced; and ink densities enhanced.’

Niklas asserts that new-generation low-migration UV flexo inks support the REVO digital flexo revolution with high pigmentation, consistent ink transfer and consistent density properties, providing REVO projects with a wide range of graphic possibilities, and excellent consistency.

Taking up the story from Esko’s perspective, Dan Pulling adds: ‘Extended colour gamut is the most logical solution for the flexo industry going digital – seven inks always in the press; no need to change anilox or ink; no special colours or colour matching; no wasted substrate; no press downtime.’

According to Dan, most PMS (Pantone) colours can be reproduced by printing seven colours on top of one another. ‘With seven colours, 90-95% of PMS colours can be digitally reproduced,’ he argues.

He predicts a new era for flexo, fully integrated into a digital workflow, as has already happened with digital presses. ‘The same file can be printed on a digital or a digital flexo press, with consistent print quality, and equivalent costs and productivity on either press – with flexo sustaining a wider range of applications in medium to long runs.’

Dan also maintains that REVO technology can provide greater design flexibility as the same job can be printed with virtually unlimited number of PMS colours; or two or more jobs can be interlocked on the same web, using totally different PMS colours. ‘REVO opens up a wide range of possibilities for graphic designers and production managers – wide flexibility in a digital REVO production flow.’

Speaking for DuPont, Friedrich Wolf adds: ‘New digital flexo plates allow for extreme consistency and print quality. New plate qualities and modified processing workflows result in high image resolution and excellent ink transfer. The solvent-free plate processing technology supports the environmental awareness of the REVO project.’ In his view, fine screen rule of 80 lines/cm is the new standard, once again changing industry rules. ‘New-generation digital plates provide the required quality, reproducing a wide gamut of PMS colours, without changing the inks in the press. The final printed quality is also more vibrant, with more natural greens, reds, oranges and blues.’

It’s his contention that new graphic opportunities are available to packaging designers – digital consistency and cost reduction, achieving previously-unattainable ‘real’ colours’.

According to Nick Harvey of Apex, UV flexo ink and digital flexo plates deliver consistent quality. ‘But,’ he warns, ‘inconsistent ink transfer and inconsistency between anilox rollers might endanger the digital consistency of the REVO standards.’

In a seven-colour separation, a key factor is to provide accurate consistency of the laydown of each colour. ‘The latest engraving technologies result in anilox rollers that overcome some inconsistencies of standard anilox designs,’ Nick relates. ‘REVO standards need a predictable ink density which can be achieved thanks to the scientifically-designed open slalom ink channel geometry that delivers an ink transfer with less than 1% tolerance. This next-generation technology provides fundamental contribution to REVO’s digital standards.’

As a further advantage he cites the need for less ink transfer to achieve the same level of opacity. ‘By overlapping seven vignettes instead of using full solids, ink transfer is reduced, as well as ink consumption. Ink costs, curing costs are reduced, and the whole PMS process is consistent and repeatable.’

Marko Tiainen of UPM Raflatac comments: ‘The REVO digital flexo revolution is setting a global standard, and this calls for consistency from all partners.’

Describing UPM Raflatac as an innovation-driven, front-running developer of self-adhesive label materials, he guarantees the same consistency of surface quality and ink reception in every corner of the world. ‘Among the benefits of REVO are cost-efficiency and a reduction in waste, and our product development supports this with materials such as those in our Fit range, engineered for cost-efficiency and process-efficiency while retaining optimal performance. New substrates and printing technology are progressing in parallel with the same objectives.’

Federico d’Annunzio of Nuova Gidue sums up: ‘Extensive digital automation in the printing press is needed to bring together all opportunities of the new REVO digital flexo process. On the printing and converting sections, servo motors and digital HD cameras substitute the eyes and the fingers of the operator with digital eyes and digital fingers. The new generation presses automatically exchange the print and die-cutting cylinders from the “old” to the “new” job, without operator intervention. Set up and production operations are digitally controlled, with limited operator intervention, who becomes a production manager and a quality tutor on the press, as most of the operations are automated and digitally controlled. Digital automation in flexo presses completes the REVO digital chain from prepress to plates, to inks, to anilox and finally to printing and converting, to achieve a full REVO digitalisation of the flexo process.’

From June 10 to 12, an open house, at Gidue’s premises in Florence, Italy, will introduce the REVO project to the labels and packaging market. Live demonstrations of the full process will be performed with the participation of all REVO team members.

[Ed’s note: For more information on the REVO project and/or to register online for the open house in Florence, visit www.revo-digitalflexo.com.]