I
now see that a project has been launched, known as the Revo Team, to further
revolutionise digital flexo. The seven members of this dream team have set
themselves the goal to drive flexo towards the new digital world of printing
and converting.
Gurus such as Niklas Olson of Flint, Dan Pulling of Esko (Dan was in South
Africa not so long ago), Friedich Wolf of DuPont, Nick Harvey of Apex, Fererico
d’Annunzio of Nuova GIDUE, Marco Tiainen of UPM Raflatac and Daragh Whelan
of Adare. They are a formidable group and I am sure that we will see a further
leap in quality, process consistency, efficiency and cost reduction.
It brought to mind an article which was published recently concerning flat top
dots and the article is well worth another and closer look. Have a read and let
us watch with interest the results from the Revo Team who met during June
in Florence.
Background
Over the years the flexographic printing industry has used several dot shapes
and structures, with varying resultant effects on plate life and consistency. It is
generally accepted that the flat top dot structure of analogue or conventional
flexo dots enables considerably longer plate life (often 2 to 5 times) compared
in like-for-like tests to the rounded dots utilised by traditional digital plates.
The introduction of Kodak Flexcel NX Digital Flexographic Plates with Kodak’s
flat top dot structure also shows analogue-type improvements in plate life over
traditional digital plates.
But why?
Kodak personnel are often asked why the flat top dot structure is better for plate
life. Intuitively the answers seem obvious, but we chose to commission
an engineering study to find an independent, science-based answer.
Seeking the scientific answer
The Welsh Centre for Printing and Coating (WCPC) at Swansea University (SU)
is a world-recognised centre of expertise in computer simulations of engineering
problems. The technique first developed at SU, and used globally today, is Finite
Element Analysis (FEA), which breaks down complex structures and situations
into a mesh of smaller elements to allow application of engineering equations
to calculate stresses. It is a standard analysis method for analysis of potential
structures for buildings, airplanes, cars, etc.
The staff at the WCPC, under the guidance of Prof. Tim Claypole MBE and Prof.
David Gethin, carried out a series of FEA studies using a commercially available
package developed at SU, to study the stresses generated with static conditions
at a series of applied deflections and conditions. They used generic dot profiles to
represent analogue, traditional digital, and Kodak Flexcel NX Digital Flexographic
Plates. The tests assume the same materials and load conditions to provide a
like-for-like set of results based on dot shape alone.
Rounded traditional digital dots
Flat top dots
The Rise and Rise
of Flexo
It is well over 35 years since I became involved with Flexo plates. When DuPont
launched Cyrel it was a quantum leap in flexo quality. For 35 or so years we have
witnessed the incredible improvements in the quality of flexo printing.
Vol 4 Issue 3 • THE RISE AND RISE OF FLEXO
By Keith Solomon
60
I
The GAPP
magazine
www.
thegapp
.co.za
