There is no question that newspapers today are
under continuous pressure to improve quality and lower waste. Advertisers and
readers are demanding that newspapers offer output quality equal to what they
receive from commercial insert printers.
In response, newspapers have greatly enhanced and
upgraded their press capabilities. But here’s another tactic publishers
frequently overlook when they are want to boost print quality: If you’re
currently running a neutral or alkaline fountain solution, switch to a mild acid
fountain solution.
Acid standard
Acid fountain solution is the industry standard
for commercial printers. In fact, printing with a pH between 5.0 and 5.5 is very
common in most European, Canadian and South American countries for coldset
printing.
Using a solution with that pH is also rapidly
becoming a trend in the United States.
Indeed, an acid pH and the addition of pure
natural gum Arabic or a synthetic gum can greatly enhance the performance of the
fountain solution.
Mild acid solutions also yield another benefit:
Water settings can be reduced by as much as 30 percent. This, of course, leads
to a substantial reduction in ink. Consequently, reduced ink and water will give
sharper reproduction, with brighter colors and sharper half tones.
Another benefit is less set-off and less
show-through.
Finally, research has determined that running
less water can help reduce or eliminate such pesky hassles as paper curling,
fan-out and circumferential register.
Keeping it clean
Mild acid fountain solutions have been used for
many years to help reduce print problems associated with tinting, toning and
other plate issues.
Indeed, my first venture into using a mild acid
fountain solution, more than 20 years ago, was to solve a toning problem. Mild
acid also offers a wider window of ink and water balance. This extra latitude
can help minimize some of the plate surface defects and variances.
The constant replenishing of the non-image area
with natural gum Arabic or gum substitute, meanwhile, helps keep the non-image
area clean. I have also seen mild acid eliminate fingerprints.
Paper efficiencies
Mild acid — as opposed to neutral or alkaline
fountain solutions — also helps reduce paper waste on press restarts. Cleanups
are also less onerous thanks to the fact that mild acids have stronger
desensitizing properties.
Years ago, concerns with acid fountain solutions
lead to the development of alkaline, and eventually, neutral fountain solutions.
However those legitimate past concerns were,
innovations in mild acid solutions have all but erased those worries.
One valid worry is press corrosion. But unlike
most neutral and alkaline products, acid fountain solutions contain corrosion
inhibitors.
It is for this reason that many of the European
press manufactures recommend mild acid products for the startup of a new press.
Users concerned about their acid content can have
their fountain solutions tested by Fogra, a print process organization based in
Germany. For a fee, Fogra (www.fogra.org.) will evaluate fountain solutions for
corrosive properties.
Bacteria concerns, meanwhile, have been addressed
by reformulating some of the ingredients used to develop the latest generation
of mild acids.
Dampeners
Mild acid has been used successfully for years on
presses armed with spraybars. Mild acid does, however, appear to be more
effective with direct dampeners than with ink train dampeners. That’s because
ink-train dampeners require the ink to carry the fountain solution to the place.
Mild acid normally removes as much as 25 percent to 40 percent of the water
pickup of the ink. Depending upon the type of ink used, this can either be a
benefit or an obstacle. To eliminate problems, perform a water pickup test on
your existing ink prior to evaluating the use of mild acid solutions.
Costs
Acid fountain solutions generally cost more than
alkaline or neutral alternatives, however, I believe they can cost less to use.
The savings in ink and paper alone can far outweigh the increase in purchase
price. So the next time your pressroom has tinting, toning, fingerprints,
mottled print, poor laydown, excess emulsification, curling, slow restarts or
complaints from advertisers about the quality, try mild acid and see what
happens.
Michael Walsh is president of C&W
Unlimited, a fountain solutions supplier based in Carlstadt, N.J. He can be
reached at at 201.933.4343 or via e-mail at mwalsh@cwpressroom.com