Metallic Powder Coatings can be produced to give a range of metallic finishes from silver
to gold and with all ranges of gloss and profile. By adding Aluminium, Bronze, Zinc,
Magnesium and Stainless steel pigments to the thermosetting Powder Coatings.
The most used pigment for silver metallic effect is Aluminium 1-2% in the leafing and
3-5% in the non-leafing form. With Aluminium pigments the fine Leafing grades will
produce the brightest silver and glossy effects these are the lower average particle size.
(4-12 microns) The Non- Leafing are higher average particle size (10-20 microns) and give
a sparkle effect.
Smooth Metallic effect Powder Coatings cannot be produced using the normal powder
coating process because the shear forces that occur during extrusion distort the metallic
particles causing them to loose their lustre. The extrusion process can produce some
excellent bright hammer finish effects but on the whole they tend to be silver and dark grey
Dry blending where the metal pigments are mixed with the thermosetting powder coatings
is a simple production method but can be highly dangerous process prone to explosion
with out the correct inerting methods and procedures. The finished powder will give a
brighter and glossy effect but the metallic pigment will tend to separate at the point of
application this in turn will cause pigment agglomeration and in the reclaim system cause
colour changes. Blended products cause major application problems because of the free
metal particles that exist within the mix including the clogging of guns during corona
The production of Metallic Powder Coatings is best achieved via the Bonding process that
is relatively safe and does not leave free metal particles within the powder when correctly
bonded. The Bonding process can be described as the complete attachment of metal
pigments to thermosetting Powder Coatings. The problems associated with separation and
agglomeration will disappear with reclaim equal to normal non-metallic powder coatings.
The metallic effect will be constant even with large batches.
The risks of incorporating the pigments, especially Aluminium. Can be eliminated by
determining a basis of safe operation for the process and using the best equipment for
Due to the specialist nature of this process only few Powder Coatings manufacturers have
moved into this process in house, with most choosing to use a Bonding service company
for Bonding the Metallic pigments into the base powder supplied by the Powder Coatings
The problem with any Bonding service is the time taken from sending the sample and
detailing the specification, identifying the required base Powder Coating, manufacturing
the base powder, having it Bonded and returning to the Powder Coating manufacturer and
on to the end user. A typical service would be eight weeks from receipt of colour pattern to
Bonded Powder Coatings.