What is Powder Coating?
So, you've heard of it, but, you're not quite sure exactly
what powder coating is. According to the Powder Coating Institute's
web page, "Powder coating is an advanced method of applying
a decorative and protective finish to a wide range of materials
and products that are used by both industries and consumers.
The powder used for the process is a mixture of finely ground
particles of pigment and resin, which is sprayed onto a surface
to be coated. The charged powder particles adhere to the electrically
grounded surfaces until heated and fused into a smooth coating
in a curing oven. The result is a uniform, durable, high-quality,
and attractive finish." There, so now you know! Or do you?
Eastwood's
HotCoat® guns, like most powder coating guns, apply
a negative electrostatic charge to the flour-fine powder (that
magical mixture of "pigment and resin"). This charge is high
voltage; up to 25,000 volts (100,000 volts on industrial guns),
but fortunately very low amperage (the amps are the part of
electricity that can really hurt you). Since this powder is
made of resins, we know that it falls in the general classification
of "plastics". As a member of the plastic family we know that
it is a poor conductor of electricity. So once the particle
is charged, it gives up that charge very reluctantly. This is
what causes the powder to "cling" to the substrate being coated.
The negative ions in the particle slowly fight their way to
the positively charged substrate. This slow flow of ions from
particle to substrate is what holds the particle on the substrate.
Putting it another way, think of the positively charged substrate
as "sucking" the negative ions out of the particles, causing
them to stick.
Why Is Powder Coating Better?
- More Durable - Powder coating gives consumers, businesses,
and industry one of the most economical, longest-lasting,
and most color-durable quality finishes available. Powder
coated surfaces are more resistant to chipping, scratching,
fading, and wearing than other finishes. Color selection is
virtually unlimited with high and low gloss, metallic, and
clear finishes available. Thanks to the UV resistance of many
of the powders, colors stay bright and vibrant longer. Texture
selections range from smooth
surfaces to a wrinkled or matte finish, and rough textures
designed for hiding surface imperfections.
- Protects the Environment - Powder coating is also highly
protective of our environment. While liquid finishes contain
solvents which have pollutants known as volatile organic compounds
(VOCs), powder coating contains no solvents and releases negligible
amounts, if any, of VOCs into the atmosphere. Thus, there
is no longer a need for finishers to buy costly pollution
control equipment. In addition, most powder coating overspray
that does not adhere to the part can be retrieved and reused.
Although this is not always practical for many low-volume
users, this can virtually eliminate the waste commonly found
in liquid finishing processes.
- Saves Money - Elimination of VOCs and reduction of wastes
saves money and helps companies comply more easily and economically
with the regulations of the U.S. Environmental Protection
Agency. In fact, one of the major elements in expanding the
market for powder coating has been the implementation over
the past 30 years of stringent air pollution control legislation.
Where Is Powder Coating Used?
- Appliances - The appliance industry benefits from powder
coating on front and side panels of ranges and refrigerators,
washer tops and lids, dryer drums, air-conditioner cabinets,
water heaters, dishwasher racks, and cavities of microwave
ovens. Powder coating has also replaced porcelain enamel on
many washer and dryer parts.
- Architecture/Building - The architectural and building market
powder coats aluminum extrusions used on frames for windows
and doors and modular furniture. Many highway and building
projects use powder coating on light poles, guard rails, signs,
posts, and fencing.
- Automotive - Henry Ford once said, "You can have a Model-T
in any color you want. So long as it's black." For an industry
once focused primarily on manufacturers' needs, powder coating
is transforming the automotive industry with faster production
times and lower operating costs, plus irresistible value propositions
for consumers. For years, conventional liquid coatings were
the standard for the automotive industry. But these coatings
can emit dangerous VOCs at their application stage. Powder
coatings eliminate most environmental concerns and the need
for costly waste disposal systems. Because powder does not
run or drip, the result is a uniform, superior-quality finish.
Conversion from liquid to powder clearcoats for auto body exteriors
is moving rapidly. Powder topcoats resist acid rain, the sun's
ultraviolet rays and road and weather damage, helping cars retain
their "showroom look" much longer and improving their resale
value. BMW and Volvo are using it on their new model cars, and
GM, Ford, and Chrysler have formed a consortium to test this
technique on their production lines.
Powder coating has made substantial inroads as a primer for
car, van and pickup truck bodies in the United States. Auto
body primers in colors will be next.
There is huge market potential for high-heat resistant powder
coatings on aftermarket mufflers, which resist corrosion, protect
against nicks and prolong the life of the muffler. Some companies
are already applying heat-resistant powder to aftermarket mufflers,
and the new-car market is thought to be two or three years away.
Powder coating is also applied to wheels, grilles, bumpers,
door handles, roof racks and exterior and interior trim. "Under
the hood" uses include oil and fuel filters, brake pads, engine
block casings, suspension components and radiators. Pickup truck
and SUV owners can purchase powder coated side steps, bed rails,
luggage racks and toolboxes as dealership add-ons or in aftermarket
stores and catalogs.
Performance car owners can find powder coated special suspension
units, carburetor parts and valve covers, plus flashy rear-view
mirror mounts and other exterior adornments.
Everyday Products - There are also innumerable everyday uses
for powder coated products such as lighting fixtures, antennas,
and electrical components. Farmers have powder coated tractors
and farm equipment. Fitness buffs powder coat golf clubs and
golf carts, ski poles and bindings, snowmobiles, bicycles, and
exercise equipment. Shop owners have powder coated display racks,
shelves, store fixtures, and vending machines. Office workers
use metal furniture, computer cabinets, mechanical pencils and
pens, thumbtacks, and other desk accessories that are powder
coated. Parents have powder coated baby strollers, cribs, metal
toys, and wagons. And home owners have lawn mowers, snowblowers,
barbecue grills, patio furniture, garden tools, electronic components,
bathroom scales, tool boxes, and fire extinguishers which benefit
from a powder coated finish. The powder coating boom has just
begun - expect more exciting uses in the near future.
Powder
Coating Guns and Kits
HotCoat
Powders
Powder
Coating Books and Videos |
