What I Learned on My Summer Vacation
Posted on Friday, August 1, 2014
Well powder fans, the 2014 PC Summit is
history now. It wasn’t exactly my summer
vacation; however, I have lots to report on.
As expected, we had a band of industry experts
expounding their knowledge of the latest technical
trends in our industry. And, as always, we had
a throng of august technologists attending and
bringing networking to an expected crescendo.
I was fortunate to emcee this event and experience firsthand
the unveiling of some of the coolest innovations taking
place in the finishing industry. Highlights of a few of
the most innovative topics are presented below.
Chris Berger of Calvary Industries shared some of the
latest innovations in zirconium pretreatment for aluminum
and steel substrates. He explained how this technology
is rapidly replacing phosphate pretreatments because
they produce significantly less sludge and operate at lower
temperatures, thus minimizing hazardous waste and lowering
Zirconium-based pretreats debuted in the late 1990s,
however the initial products exhibited a number of problems,
including flash-rusting, complicated control testing
and inconsistency across substrate types. Pretreatment
scientists went to work and developed solutions to these
issues. Calvary Industries, in particular, found that by
modifying the zirconium material with a proprietary alternate
pretreatment chemistry these shortcomings could be
ameliorated. In addition, the process is much more robust
and user friendly.
Chris provided a few examples
where traditional iron phosphate and
zinc phosphate pretreatment systems
were converted to Calvary’s Advantech
™ technology and demonstrated
the improved performance and lower
operating costs. The most compelling
case depicted the change-out of a nine
stage zinc phosphate to a simpler six-stage
process based on Calvary technology.
The new system is less prone
to flash-rusting, uses less heat, is not
pH sensitive and produces essentially
Gas Catalytic Infrared (IR) Curing
Marty Sawyer, one of the principles
at Trimac Industrial Systems, provided
a thorough tutorial on this intriguing
curing technique. Gas catalytic IR relies
on the combustion of natural gas
(methane) to create infrared radiation
that can be used to transfer heat energy
to a coated surface. This type of
combustion is highly efficient because
of the platinum catalyst embedded in
Marty explained how this innovative
technology uses the same technique
employed in automotive exhaust
systems. The process creates IR
in a very efficient manner combusting
nearly 100 percent of the gas and expelling
only a small amount of CO2
and water. This is possible because the
catalyst lowers the activation energy
of combustion and therefore reduces
the energy needed to create the infrared.
Gas catalytic combusts methane
at around 250°F compared to the
traditional combustion temperature
of 1200°F. In addition, this process
is flameless and therefore much safer
than conventional gas-fired burners.
Gas catalytic IR can replace less efficient
gas convection ovens and also
reduce the time to cure a powder coating.
Faster cure times result in lower
capital equipment costs and a significantly
smaller process footprint. Another
advantage of gas catalytic IR is,
like other IR technologies, the majority
of heat is delivered to the coating
material and not the work piece. This
reduces the overall energy needed to
cure the coating.
Marty showed a number of examples
of finishing lines that had converted
to gas catalytic IR including
ones running complex parts, thick/
dense parts and diverse mixtures of
parts. In all cases the finisher was able
to reduce operating costs, shorten process
times and reduce work-in-process
with this environmentally friendly
Steel Quality, Pretreatment
Effectiveness and Solutions for a
Globally Compliant Era
A few months ago, I authored a
piece titled “Don’t Blame the Powder”
for corrosion and/or adhesion failures.
I chided that the culprit is usually the
metal pretreatment and not the coating.
However Dr. David Chalk from
DuBois Chemicals Inc. begs to differ.
He emphatically posited that it’s typically
not the pretreatment at fault but
the quality of the metal substrate instead.
His comprehensive explanation
made a believer out of me.
Dr. Chalk talked about the evolution
over the past 20 years of the steel
industry. Most significant is the loss of
blast furnace production operations
in the Western world. He states that
over 90 percent of all steel-making
blast furnaces are now located in China.
On the surface this doesn’t seem
earthshattering news; however, this
development coincides with the practice
of incorporating up to 25 percent
scrap metal into each batch of steel.
What this does to pretreatment technologists
is create a moving target for
their chemistry’s performance. The
highly variable carbon and alloying
element contents in cold rolled steel
wreak havoc on cleaning and pretreatment
quality. Dr. Chalk recommends
using a versatile zirconium chemistry
to combat the inconsistency of steel
He also commented on the global
regulatory push to restrict a number
of elements useful in pretreatment
technologies, including many metals
and fluoride based compounds. The
use of fluorine chemistry in zirconium
pretreatments will quite possibly
restrict the commercial use of these.
A potential alternative to existing
pretreatment processes is to employ
strong acid based organic compounds
for metal preparation prior to powder
application. DuBois Chemical has developed
prototype materials and has conducted successful trials on commercial finishing lines.
This technology uses no metals, operates at ambient temperature
and works on widely variable quality steels.
A number of other very interesting technology advancements
were presented during the 2014 PC Summit.
I will be reviewing many of them in the upcoming issues
of Powder Coating Tough magazine. Stay tuned, powder
Kevin Biller is technical editor of Powder Coated Tough and the president of The Powder Coating Research Group. He can be reached at firstname.lastname@example.org