Home' FLEXO Magazine : August 2016 Contents advantages of EG printing are many and relate to both increased effi-
ciency and standardization of the process. Since the same sets of an-
iloxes and inks are used for all jobs, no time is wasted on changeovers,
washups and spot color matching. In addition, the ink inventory can
be dramatically reduced and jobs with completely different colors can
be printed in one run. At the same time, digital processes for color
separation like contract proofing and color control at the press foster
the standardization of the flexo process and ensure the consistency
and repeatability of jobs.
It is not only the print quality the machine delivers that ensures a
user’s competitive edge but also its fast changeover capability. In
times when print designs are increasingly short lived and the actual
products to be presented are subject to rapid change, the capability
of a press to profitably produce even smaller run lengths is key to the
return on investment it provides.
Potential savings can primarily be achieved when setting up a job. Al-
most all machine manufacturers today offer systems with semi or fully
automatic impression and registration adjustment, which substantially
reduce the time required and the amount of waste.
The most efficient systems are those that shift the entire impression
and registration related setup process to the plate mounting stage,
meaning the press is no longer “abused” for makeready at all, instead
being available exclusively for production printing. A system of this
kind additionally reduces waste to almost zero, and it offers absolute
process reliability, i.e. the setup results can be reproduced at any time,
regardless of such variables as shift, ambient temperature, drying
properties of the ink, etc.
For printers who do not use EG printing, (spot) color matching—if
performed manually—is another time consuming process step when
setting up a new job. To make this important setup step independent
of the operator’s skills and to dramatically reduce the time wasted
to match color, systems are available that help to boost productivity,
specifically with job structures that require many changeovers per
day. Some manufacturers even provide solutions that not only include
hardware and software but also analysis of existing processes and
consultation as to how they can be improved.
CANTILEVERED SLEEVE SYSTEMS
Today, even the widest CI flexo presses are featuring cantilever sleeve
systems which, in conjunction with auxiliary systems, allow for the
fast and ergonomic handling of sleeves and adapters. Fully automatic
sleeve change systems not only save labor costs and increase opera-
tional safety, but also dramatically reduce changeover time.
When it comes to energy consumption, as well as ink and solvent
use, even the standard versions of modern flexo presses are no longer
comparable with models that were the state of the art just a few years
ago. Like modern automotive drives, they offer far higher efficiency,
i.e. substantially less energy has to be used to print the same area.
Moreover, some manufacturers offer “green” packages that focus on
the machine’s principal consumers.
There is a wide range of options for reducing or avoiding energy
losses in connection with drying. Control of the blower drive output
as a function of machine speed and the number of printing units used
prove to be additional efficient measures. A further characteristic of a
drying system geared to saving energy is intermediate drying nozzles
that can be individually opened and closed when required.
An energy and consumption efficient inking and cleaning system is
characterized by short pipe and hose lengths, and thus a small total
volume, special compressed air ink agitators with low compressed
air consumption, and individually variable cleaning programs with
minimum solvent consumption. The profile of a “green” machine is
rounded off by additional features, such as servo drives with energy
recovery modules and energy saving modes that switch the machine
to the most efficient state at the push of a button during downtimes
and production times.
It goes without saying that these diverse technologies for improving
flexo quality and saving energy require additional investment. How-
ever, if the investment pays back after just a short time, the people
responsible for making purchasing decisions now find it much easier
to go for “green,” as they have long since stopped looking at just the
acquisition costs and now consider the total cost of ownership (TCO)
instead. This is continually being proven true as ecofriendly produc-
tion is also being acknowledged by consumers.
THE NARROW WEB MARKET
Revolutionary technologies have already changed our industry in the
past 14 years: new and friendly flexo heads, new stripping units and
advanced register and pressure control are already standards of pro-
ductivity and efficiency in the narrow web market for the production
of labels and flexible packaging.
An up close look at the detail of a new print unit with advanced pressure and
AUGUST 2016 | FLEXO 47
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