Canadian Finishing & Coatings Manufacturing Magazine - May/June 2023 - 28

INDUSTRIAL FINISHING: OVENS
" A combination oven can also offer significant savings in
space and energy cost over a convection oven alone, " says
Chou.
When looking at gas catalytic and electric IR systems
versus convection, Trimac's Sawyer says that catalytic is
three times faster than convection and electric is 10 times
faster because it's hotter. IR will make the powder gel faster
because the fundamental difference between the technologies
is that convection requires the entire part to be brought up to
temperature before applying powder.
" With IR, you can get the powder to gel and kick over when
the interior of the part is still not up to temperature. You can
get all of that chemical reaction of the powder converting
to happen faster before the heat sink of the interior of that
part can pull the energy or BTUs away, " she says. " Infrared
is harder to work with, there's no question. Catalytic is the
hardest to work with because if you're doing a variety of parts,
you have to really pay attention to how you're hanging them,
the material flow and how to operate the technology to control
zoning. But both catalytic and electric are controllable. If you
have parts that have a thicker section, you can add more heat
where needed. You can't do that with convection. "
Trimac recently launched the ProCat, a catalytic and
electric combination oven technology that boosts the catalytic
with the electric capabilities. Sawyer says that if you're doing
a lot of fast production with a catalytic oven, the system can
get pretty big. The ProCat allows them to shrink the catalytic
side and speed up the process even more. For example, if a cure
application had a 45-minute oven time, a straight catalytic
system would take 15 minutes with the same line speed and
production. This process can be achieved in 12 minutes with
the ProCat design.
Chou agrees that IR systems offer shortened cycle times
but points out that CIS's gas catalytic heaters burn at a much
lower temperature than a traditional burner.
" Our combustion process takes the chemical equation of
CH4 + 202 + catalyst -> CO2 + 2H2O + infrared heat. We emit
little to no NOx. A convection oven would have a traditional
burner box with an open flame that would burn the gas at a
much higher temperature, " says Chou. " We've also spent a lot
of effort developing a new manufacturing process that will
reduce the effect of catalyst migration. All catalytic heaters
have an active portion bound to a substrate. With heating
and cooling, the catalyst [active portion] tends to migrate and
form clumps, reducing the effectiveness of the gas heater. Our
new process eliminates or reduces the catalyst migration, and
we feel this will extend the life of the panels. "
For companies with older convection ovens that aren't
keeping up or causing them to slow down the production line,
Sawyer says, " the easiest answer is to add a boost. It can be
IR electric or gas catalytic, it doesn't matter. You can put it
outside of the oven or inside depending on available space and
how you want to configure it. That is a guaranteed solution for
issues like the oven isn't getting hot enough or the parts aren't
quite getting there so you have to slow it down. You can do
system improvements like this that will noticeably improve
throughput. "
CIS recently had a customer that was spending over
$10,000 a month outsourcing its powder coating process and
28
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CIS's new oven solution for a company bringing powder
coating in-house
When looking at gas catalytic and electric IR
systems versus convection, Trimac's Sawyer
says that catalytic is three times faster than
convection and electric is 10 times faster
because it's hotter.
wanted to bring it in-house. The issue was that they had a
convection oven that didn't work, and they were moving to a
new facility within a year.
Instead of installing a new oven, just to relocate it 12
months later, CIS used the existing convection oven frame to
design and retrofit a temporary solution and keep the costs
down.
" The customer was able to use the temporary solution for
about eight months before moving to the new facility. We
brought back all the components and reused them to build
a new oven, " says Chou. " Between the time the temporary
solution was installed to the time that the new oven was built
at the new facility, the system had paid for itself from the
monthly savings of bringing the process in-house. "
Oven technology manufacturers and their labs are poised
to work with shops to improve existing processes, enhance
throughput and efficiencies and, of course, develop the
optimal solution for any process. And since everything we see
and touch that is manufactured is finished in some way, the
demand for finishing systems is constantly growing.
http://www.cfcm.ca
Canadian Finishing & Coatings Manufacturing Magazine - May/June 2023

Table of Contents for the Digital Edition of Canadian Finishing & Coatings Manufacturing Magazine - May/June 2023
