Canadian Finishing & Coatings Manufacturing Magazine Jan/Feb 2023 - 35

INDUSTRIAL FINISHING: REFLECTIVE COATINGS
Night Vision
While cool coatings aren't new, continuous
advancements in pigment technologies have
continued to drive up their value in terms of
substrate protection, aesthetics and cooling
performance.
Unlike IR-reflective pigments for architectural
applications that are designed to cool, PPG
Envirocron LUM retroreflective powder was
developed to enhance safety at nighttime and lowlight
conditions for use on things like guardrails,
bikes, machinery, safety equipment and signage.
This commercial retroreflective powder was
developed after PPG scientists found a way to
embed-and keep-reflective glass beads at the
surface of the powder.
technologies are increasingly coming into play with the shift
toward darker colours, particularly in roofing, since they offset
the heat absorption that typically comes with deeper hues. A
standard black pigment has a total solar reflectance (TSR) value
of about 5 per cent. But a black IR-reflective pigment reflects
about 50 per cent of infrared energy, lowering the TSR to the 2530
per cent range. These coatings, commonly used on roofing,
wall panels and other metal building components, lower building
temperatures and reduce the energy demands needed for cooling.
What are some of the challenges of developing a
product to be reflective and durable?
While cool coatings aren't new, continuous advancements
in pigment technologies have continued to drive up their
value in terms of substrate protection, aesthetics and cooling
performance. Cooling is essential, but the ability of these
pigments to withstand exposure and lasting durability is also
critical. The specific chemistry of the IR pigments determines
these properties.
While cooler, more comfortable buildings are important,
these fade and chemical resistant IR-reflective pigments also
help to preserve the structural integrity of the substrate by
reducing corrosion, warping, thermal expansion and polymer
degradation-protection that can extend the life cycle of the
substrate.
Can you provide examples of architectural
applications and the benefits of IR-reflective
properties?
The Paulding County Georgia case study is a well-known 'cool
roofing' test case performed by Oak Ridge National Laboratory
enlisting the participation of two elementary schools being built
in different parts of Paulding County Georgia. Both schools
used the same exact blueprints and had the same square footage.
Although unintentional, both schools also faced the sun in the
same direction. By prior arrangement with the school board,
Oak Ridge arranged for the thermostats for both schools to be
controlled off-site at the district office for one year.
One school had an evergreen colour roof that used standard
pigmentation that measured 12 per cent TSR. The other school's
evergreen colour roof used IR reflective pigmentation that
measured 29 per cent TSR. At the end of the one-year, the school
with the IR reflective showed a savings of $8,054 in cooling/
" Unlike reflective materials that reflect light
in a scattered, diffuse pattern like a mirror,
retroreflective surfaces return light in a more direct,
focused pattern that heightens illumination, " says
Gary Edgar, PPG's building product specification
manager. " The incoming light beam bends as it
passes through the glass bead before reflecting
off a mirrored surface behind the bead. The light
beam then bends once more before returning to
the source. This process gives drivers more time to
see-and react-to hazards ahead. "
In addition to its safety enhancing features, this
patent-pending formulation provides all the benefits
of PPG powder, including resistance to corrosion,
chipping and abrasion.
heating expenses. Those results projected to a savings of about
$282,000 over the anticipated 35-year life of the facility.
Gary Edgar is the specification manager for PPG's building
products, which includes factory applied Duranar and Coraflon
fluoropolymer liquid and powder, along with ADS field applied
coatings. Edgar has been with PPG 22 years, with 17 years devoted
exclusively to PPG's Air-Dry fluoropolymer and BRP Build Restore
Protect coating systems. His responsibilities include product
recommendations, product training, warranty approval, and he is
a NACE Certified Coating Inspector.
January/February 2023
35
Canadian Finishing & Coatings Manufacturing Magazine Jan/Feb 2023

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