Canadian Finishing and Coatings Manufacturing: Nov/Dec 2022 - 24

PAINT AND COATINGS MANUFACTURING: HEAVY DUTY POWDER COATINGS
" We're seeing a lot of agricultural companies moving away
from phosphates and towards zirconium. It's not necessarily
because they're specifically being environmentally conscious,
but the farmers they're selling too are, " says Eric Reinhart,
senior account manager for CPI. " But any time you can get rid
of phosphates for the environment, it's a good thing. "
Reinhart continues, " If you test zinc-phosphate, which is an
industry standard, against zirconium, the results for corrosion
or adhesion are typically the same, but what you do get with
zirconium is more consistency. The zirconium is a much
thinner, more uniform film that's applied to the surface. With
zinc, you're putting on a thick coating, which has a crystalline
structure to it that can cause weak spots in the coating. "
CPI's Steelcote, the zirconium-based product, is easier
to use and maintain from an operational viewpoint. With
phosphate solutions, facility have to deal with a lot of sludge
that is generated when cleaning the parts. It needs to be cleaned
out of nozzles and tanks, and requires a mud press to filter the
phosphate sludge and prepare it for landfill.
" That equipment is expensive and difficult to maintain.
When you look at the costs associated with the labour to clean,
the equipment required to filter the sludge out and sending
it to the landfill, it's not cheap. When you move to zirconium,
you eliminate 98 per cent of that, " says Reinhart. " Zirconium
can also be run at an ambient temperature, where phosphate
systems have to be at 54 to 57 degrees C. Think about that
savings in energy alone. "
Circling back to coating sharp metal edges, Reinhart says
that any time you have a laser cut edge, that's going to be a point
where the film is thinner than other areas-be it zirconium,
phosphate, powder or liquid coatings. " Zirconium will give you
the benefit of consistency, but I wouldn't say it will solve the
problem. There are some things you can do with a powder coat
and there are certain powders that are formulated for good edge
coverage. "
Clarke says, " There are specialty powders for this industry to
help with the flow issues on sharp edges. You have to balance the
agents in the formulation for slightly less flow, so it doesn't pull
away and gels properly. But for heavy equipment applications,
Like many other industries, processes and
equipment are all moving towards automation.
While this move was inevitable, the lack of
workforce is one of the key drivers, but also the
need for consistency and repeatability.
it's typically a thicker coating such as 120 microns, compared to
the standard 60-to-80-micron thicknesses. It also depends on
where the equipment is going to be used. In harsh environments
where there are extreme temperature changes, that aspect would
have to be built into the specification of the powder used. "
Of course, these large parts require larger ovens and to speed
things up Clarke says that these industries are looking for low
bake powders. And while there is a move to UV curing, that
technology is still a line-of-sight cure and can only be used for flat
parts. Most manufacturers are still relying on conventional style
ovens for curing purposes. And that is why low bake powders tend
to be what these industries are looking for because it reduces the
time in the oven and the amount of heat needed for those powders.
Like many other industries, processes and equipment are all
moving towards automation. While this move was inevitable, the
lack of workforce is one of the key drivers, but there's also the
need for consistency and repeatability.
Sames' Inobell rotating electrostatic powder bell sprayer is
designed to apply more powder to a product quickly, saving time
and powder while delivering a uniform thickness with better
adhesion.
24
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Canadian Finishing and Coatings Manufacturing: Nov/Dec 2022

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