The history of
powder coating begins in the late 1940s and early
1950s, at a time in which organic polymers were
still being spray coated in a powder form onto
metallic bases. Dr. Erwin Gemmer, a German
scientist, then developed the fluidized-bed process
for the processing of thermosetting powder coatings
and registered an appropriate process patent in May
1953. Between 1958 and 1965, literally all powder
coatings, generally only functional applications
with a film thickness of 150 µm to 500 µm, were
processed by means of fluidized-bed application.
Electric insulation, corrosion and abrasion
resistance were in the foreground. The coating
materials in those days were comprised of nylon 11,
CAB, polyethylene, plasticized PVC, polyester and
chlorinated polyether, among others, and at the same
time, thermosetting epoxides, e.g. for dishwasher
baskets (PVC), for heat insulation (epoxide), for
boat accessories (nylon) and metal furniture (PVC,
CAB).3 It was the Bosch company that
developed the basic type of epoxy resin powder in
their search for a suitable electric insulation
material.
The much to high film thicknesses for the numerous
other applications, and the technology of
electrostatic processing of powder coating, which
was developed soon thereafter in the U.S.A., and
commercialized between 1962 and 1964 in the U.S.A.
and Europe, did overshadowed the fluidized-bed
process. With the spray-guns made by the Sames
company for electrostatic application (which gave
rise to the term "Samesizing"), this hurdle was also
overcome. Between 1966 and 1973 the four basic types
of thermosetting resins, which are still utilized
today, were developed and commercially distributed.
They are epoxy, epoxy polyester hybrid, polyurethane
and polyester (TGIC). The number of powder coating
plants in Germany alone rose from four in 1966 to 51
in 1970. From the early 1970s, powder coating then
began its march of triumph worldwide, although the
growth of the powder coating market until 1980 was
modest. Powder application systems until that time
were expensive, the film thicknesses too high for
commercial use, color change problems and high
curing temperatures greatly limited the color range,
effect and substrate diversity.
