“Asia, especially China and India, are growing rapidly, as is
Eastern Europe,” agreed Singhal. “Rohm and Haas is able to
supply customers in these and other regions from local manufacturing plants and can provide technical assistance from
local research centers as well. Double-digit growth in these
regions is expected to continue.”
Despite these reasons for optimism, there are several
PPG helps build out wind turbine industry
BY CHARLES W. THURSTON
CONTRIBUTING EDITOR
PPG Industries may be best known for its architectural
and automotive paint and coatings lines, but a growing
business area for the company is the demand for its specialized fiberglass and coatings used in wind turbine blades.
“PPG’s high-strength fiberglass and corrosion-resistant coatings are enabling the wind power market,” said Cheryl
Richards, global market development manager for wind energy
at the Pittsburg-based company. “If wind turbine OEMs used
metals or other composites, because of their weight and lack of
durability, wind power would be less efficient.”
Demand for wind turbines—and components such as
blades—is hot. Over first-quarter 2008, there were 1,400
megawatts of wind power added in the U.S., according to
the American Wind Energy Association. A megawatt will
power close to 800 homes for a year, according to the U.S.
Department of Energy. By project count, last year there
were an estimated 15,000 wind turbine installations in the
world and projections of growth in the market is close to
22% over the next five years.
A typical wind turbine of 1.5 megawatts has a rough cost
of approximately $1.7 million per megawatt, translating
into a $2.25 million turbine, according to Richards. Such a
machine has three blades that each measure approximately 40 meters in length and can weigh in the vicinity of
12,000 pounds apiece.
The fiberglass fibers that PPG manufactures for these
blades are only 17 microns thick, and aggregated into bundles called a single-end roving. The fabric that the OEMs
use consists of the fiber in a multi-axial construction, with
layers stitch-bonded with polyester thread. The assembled
fabric is enmeshed in a resin, and finally coated through
either an epoxy or a polyurethane coating system, or in
some cases, in both.
“Our blade coatings portfolio included both
polyurethane and epoxy systems each of which is
designed to address specific performance issues, within
which the main drivers are extreme durability, ease of
use and high productivity or throughput enhancement,”
said Dave Chapman, the commercial marketing director
for PPG’s automotive refinish business. “Flexibility is an
issue because the blades flex, and rain and environmental erosion particulates can accelerate erosion of the
challenges that are affecting the industrial coatings market including the rise in raw materials costs, energy prices
and the economic slowdown. “PPG is dealing with challenges by focusing on the development of sustainable and
renewable products that help to lower energy prices,” said
Horne. “Our company is also paying close attention to
results of voice-of-the-customer interviews to ensure all
coating, especially on the leading edge of the blade.”
Leading wind turbine OEMs have stated goals of building
blades with a 20-year lifetime, so durability is a prerequisite
in coatings design. “Important factors are color and gloss
retention, which is negatively impacted by ultraviolet light
exposure,” said Chapman. “Emerging issues are ability for
the coating system to shed ice, dirt and bug deposits, which
improves turbine efficiency. Recently, turbines installed in
India have exhibited significant blade leading edge erosion
due to wind-blown dust and sand, and the turbine OEMs
are looking to companies like PPG for solutions.”
“Epoxy primer systems are typically used for adhesion
and moisture resistance, as well as for inter-coat adhesion.
Polyurethane primer and/or topcoat systems are used for
application flexibility, color and gloss retention, and
throughput enhancement, like going wet-on-wet from the
primer to the topcoat. And in some cases OEMs use
polyurethane on top of epoxy,” explained Chapman. The
coatings are typically high solids/low volatile content formulations, responding to rising interest in waterborne and
powder technologies among turbine OEMs.
“PPG also manufactures the coatings for the towers,
including zinc-rich and epoxy primers, and polyurethane
and polysiloxane topcoats, which are applied in two or
three-step processes, depending on customer specifications
and performance expectations,” added Chapman.
“There may only be $3,000 worth of blade coatings on a
$2 million turbine, but the blade is arguably the most
important element of the entire assembly in terms of its
primary function of turning the electrical generator shaft,
so the blade coating helps to protect the entire investment,”
concluded Chapman.
Leading wind turbine OEMs have stated goals of building
blades with a 20-year lifetime, so durability is a prerequisite
in coatings design.
