Environmental
Impact of Powder Coating
Despite all the care that is taken to protect the environment,
there are still benefits to be gained. More importantly, the
long term effect of powder coating the product for corrosion
protection. Our coating system protects the metals which are
exposed to the project conditions, which in turn enjoy a longer
lifetime and require far less maintenance. Decay and early replacement
of parts are prevented or at best minimized.
In
the long run, powder coating will replace its counterpart, wet
paint, in more and more areas. Technically, powder coating competes
with wet paint head to head. In addition, powder coating is more
friendly to the environment than wet paint, for the same cost,
yet powder coating also has the advantage of superior mechanical
and anti-corrosive properties. Whereas wet paint is all washed
up!
Another
advantage of using powder coatings is the subtraction of solvents.
The powder is applied without any additives. The harmful emission
of V.O.C., as used in wet paint, does not occur. The environment
also benefits from the electrostatic adhesion of the metal to
the powder particles. This adhesion creates a smooth and even
layer that covers the edges of the metal object. This eliminates
sharp edges that need to be ground into shape. The powder, not
attracted to the substrate is contained and reused. Wet paint
overspray has to be disposed of as chemical waste.
back
to top
Why
Powder Coat?
To protect steel from being affected by corrosion it may be provided
with a powder coating. During this process, powder is electrostatically
applied to galvanized or a black steel product. It is then cured.
The very durable coating that is formed protects the underlying
metal and gives the object a shiny and bright appearance.
back
to top
The
Benefits of Powder Coating?
Powder coatings are applied to steel, hot dip galvanized steel
and aluminum as an anti-corrosive layer. The powder is electrostatically
applied to the metal. No solvents are used in this process, which
means that it is far more friendly to the environment than the
alternative wet paint process. Powder that is not adhered can
be reused, whereas over sprayed wet paint has to be disposed of
as chemical waste.
Powder coatings have outstanding mechanical properties, they are
elastic and resistant to impact and wear. This makes powder coating
ideal for applications in areas with a high risk of damage, such
as stairwells, public areas, gates, lamp posts, etc.
The
method for applying powder coating, electrostatic spraying, results
in a very good coverage of edges. This sharply contrasts with
the wet paint process, where the pressure of the spray gun pushes
the paint off the sharp edges. During the powder coating, the
powder is attracted evenly to all surfaces.
back
to top
The Powder
Coating Process
- Incoming
Material
Incoming materials is closely checked for suitability.
-
Attaching the Product to Transport Beams
The material is suspended on the transport system.
-
Degreasing
The material is alkaline cleaned and then rinsed.
- Pickling
In a bath with inhibited phosphoric acid, the product is pickled
and then rinsed.
-
Phosphating
An active anti-corrosive layer of zinc phosphate is applied then
rinsed.
-
Passivating
During this process, the layer of zinc phosphate is sealed with
a hexavalent chromating agent of very low weight. The material is
then rinsed.
- Rinsing
with Deionized Water
The material is rinsed with e-ionized water to remove remaining
metal salts, which will cause osmosis.
- Drying
The steel is dried in the drying oven.
- Powder
Coating
The powder is charged to 80,000 volts and then sprayed onto the
grounded steel.
- Curing
According to the powder suppliers' specifications, the steel is
heated to a temperature between 170° and 200° C. The resin cores
melt and a smooth homogenous coating is formed.
- Final
Inspection
The products are checked by the quality inspectors. Test panels
that are processed together with the main material are subjected
to a number of standardized tests.
-
Packaging
To prevent damages during shipping, the product is carefully
packed prior to transport.
back to top
|