thermosetting powder coating
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- Category :
Paint and Coatings
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Product description:
Electrostatic powder coating is one of the most environmentally
friendly and economical technologies in surface treatment. Since the
early 60’s, powder-coating paints have been available on the market
and their problem-free production and processing made powder coating
a well-established and commonly recognized technique. In fact, powder
coatings are
- environmentally friendly
- energy-saving
- safe to handle and process
- highly economical.
New developments focus on thin-film powders, powders for specific
applications and radiation curing systems.
Electrostatic powder coating is based on the fact that particles with
opposite charges attract each other. This is why most of the conductive
and thermally stable solids are suitable for powder coating. Today,
electrostatic powder coating considerably increases its presence in the
domain of metallic objects such as:
- aluminum profiles
- fa鏰de elements
- household appliances
- automotive accessories (e.g. rims, roof racks)
- office furniture
- storage equipment
- outdoor furniture
- wire products etc.
The powder coating process:
Dry coating powder is filled in a hopper, fluidized or stirred and
subsequently transported by means of compressed air via injectors to
the powder gun. In this gun, high voltage is created from a low voltage
of 10V utilizing the cascade principle. During the spraying process, one
or more electrodes charge the powder with 60 - 100 kV.
An electrical field is generated between the gun and the grounded
workpiece. The powder particles follow the field lines and, due to the
residual charge, remain bonded to the object (3). Once coated, the
workpieces are either manually or automatically transferred to a curing
oven. Plastic powders are cured at temperatures between 140ºC and
200ºC, fusing into a smooth coating with layer thicknesses of 30 - 80μ
for decorative and 200 - 500μ for functional purposes.
Enamel powders may be applied in a layer thickness range of 80 - 200μ,
requiring sensitively higher curing temperatures varying from 780°C to
830ºC due to their specific chemical properties.