The Screen inkjet presses with Tecnau unwinders –
complete print to finish workflow is faster and cheaper than
litho

 

Bluetree Group is the first UK site to benefit from new
near infra-red (NIR) drying in its Screen Truepress Jet 520HD
inkjet presses. 

At an open day last week, co-hosted by suppliers Screen, Tecnau
and IFS, the Rotherham-based trade printer which operates the Route
1 Print and instantprint.co.uk brands, explained how it is using
Screen’s inkjet presses to produce work more cost-effectively than
litho alternatives.

‘The Screen press is more productive than a B1 press all in – a
Heidelberg plus CtP, guillotining and folding versus the Screen
plus Tecnau line at one third of the cost. On a perfect bound book
500 run, it was two-thirds of the cost on materials too,’ noted
managing director Adam Carnell, adding that the staffing
requirement for the digital production route was two versus six for
the litho one.

Part of optimising the inkjet press workflow is in the
post-print drying stage. Screen Europe’s Cees Rem explained, ‘The
drying challenge is to remove water from the ink, not from the
paper, which increases tension in the sheet that can lead to
cockling or wrinkling. Drum-only drying can dry the inside of the
sheet, which can be problematic with thin stock.’

Screen’s solution adds an NIR dryer to the heated drum and “air
knife” approach in which the layers of moist air above the wet ink
is blown away continuously. The NIR unit is tuned to a specific
wavelength that Mr Rem said means that 90% of the emitted energy
goes into drying the ink and not the paper. ‘This allows faster
production speed, with near-instantaneous fixing of the ink,’ he
added.

Also key to optimising throughput from the Screen presses is
pre- and post-press equipment form Tecnau. This includes two Roll 9
unwinder and web cleaner units feeding the presses, plus Double Cut
& Stack 2325 cutter/stacker systems with “soft touch” grippers
that avoid scuffing or handling marks on the printed sheets by
handling by the edges only, a feature that Mr Carnell said swung
the finishing equipment choice to Tecnau rather than Hunkeler. Book
binding and other finishing tasks are handled by a variety of
Horizon equipment, also supplied to Bluetree by IFS.

Bluetree is also using a Tecnau SheetFeeder IG roll-to-cut
system to provide bulk sheet feeding to one of its four Xerox iGen
toner presses. This enables continuous operation for up to eight or
more hours from a single paper roll without requiring lifting of
stacks and can reduce paper costs. A version for the Xerox Brenva
sheet-fed inkjet press is also in development, said Tecnau’s Harm
Jan Hulleman.