SMART DESIGN

LABELS&LABELING |87
Printed electronics
revolution
A RESEARCH PROJECT technology innovation centre in the UK is demonstrating how converters can create
their own smart label operations using standard narrow web equipment. Andy Thomas reports
The Centre for Process Innovation (CPI)
has installed a custom-built, multi-process
narrow web Nilpeter press to a UK
government funded research institute as
a test bed to develop printable electronics
for a variety of applications including
labels, cartons and flexible packaging.
The press will form part of the Integrated
Smart Systems line ( ISS) which will
enable electronic components to be
integrated with printed circuits.
Although electronic circuits are already
being printed on flexible webs, these are
often located in dedicated and expensive
clean room operations using expensive,
bespoke equipment. The project at the
Centre for Process Innovation (CPI) aims
to demonstrate that any label converter
using commercially available equipment
can be part of the Integrated Smart
Systems supply chain through printing
of conductive inks print Integrated Smart
Systems (ISS) – electronic components
integrated with printed circuits -in a
standard pressroom environment.
The Nilpeter press is a 16in wide
machine specified to handle paper, carton
board, films, foils and label stocks with
thicknesses between 25-370 microns.
The modular machine includes two MO4
offset units equipped with conventional
and UV curing stations; two FA4 flexo
units able to run with water-based, solvent
and UV drying systemsinks; two screen
units with for UV inksand water-based
drying; and a solvent gravure unit. The
press operates in both reel-to-reel and
reel-to-sheet modes, and can re-register
from unit 1, allowing CPI to simulate
larger presses with multiple print stations.
Auxiliary processes include de-lam/re-lam,
UV lamination, cold foil and die cutting/
sheeting.
The process of manufacturing
Integrated Smart Systems pieces starts
with printing the label or carton’s graphic
elements, followed by printing ‘large
area’ electronic circuits. After sheeting,
the pieces are coated with conductive
adhesive on a flatbed DEK screen press
with a print accuracy of 10 microns. A
commercially available pick & place unit
used extensively in the electronics sector
then positions miniature components –
which might include chips, flexible LED
screen displays, batteries or even tiny
loudspeakers – onto the printed circuit
tracks. The sheets are cured in an oven
to bond the components to the printed
circuits, forming both a structural and
electrical connection. The oven can
handle both air-drying and UV-cured
adhesive systems.
As a final stage, the ISS sheets are
converted into short runs of finished
labels, flexible packaging or cartons.
Finishing equipment includes an Esko
Kongsberg i-XE 10 digital cutting table to
cut & crease boxes and kiss cut labels.
A Trotec CO2 laser handles fine cutting,
engraving and ablation of circuits.
The operation is also supported by
CPI’s wide range of sophisticated analysis
equipment to measure material, ink and
structural properties.
CPI is supporting the ISS operation with
a wide range of sophisticated analysis
equipment to measure material, ink and
structural properties.
CPI TEAM ISS
Running the project platform is ISS
programme manager Bela Green,
supported by technical print manager Neil
Porter. Porter draws on a wealth of narrow
web print operator experience at leading
converters including CCL Label Clondalkin
Group (formerly Harlands Labels).
The CPI team is looking for partners
from across the supply chain to take
the ISS project forward, from brand
owners and designers to suppliers of
inspection equipment, substrates, inks
and pre-press equipment. The ISS line
at CPI will be available for development
CPI technical print manager Neil Porter in front
of the multi-process modular Nilpeter press
work, prototyping, scale-up and pilot
production.
The research results will be freely
available to all participants for commercial
implementation.
A key task will be assessing the
performance of the conductive inks.
‘We need to get total uniformity of ink
coverage and no pin-holing or scratches
on the printed surface if we are to achieve
the required levels of conductivity,’ says
Porter. ‘So scuff and rub testing will be
critically important, particularly when the
label is on the applicator line. We will be
evaluating print inspection systems to see
if they are adequate to detect these kinds
of flaws. It is more a question of uniform
coating than high print resolutions.’
Another issue to be researched is how
to clean conductive inks in each
print process.
Although adhesive coating and pick and
place are currently off-line operations,
Porter believes both processes could
eventually be made modular and run
in line with a narrow web press. ‘You
would print a mark possibly to register
both adhesive coating and pick & place
systems.’ If successful, the Integrated
Smart Systems project line at CPI could
mark a watershed in the history of label
production. For the first time, label
converters of any size will be able to
start up their own smart label operation,
tapping into leading edge research into
micro-electronics to create entirely new
applications for designers and end users
across the supply chain.
JULY 2012 | L&L