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POWDER COATING TECHNOLOGY
Among the oldest traces of metal coating left by human being is the great Egyptian monument
" Tot Ankh Amoon " thousands of years ago. Since those days till recent decades the only player in the
field of metal coating was the liquid form of paint.
"Better coating and less polluted environment", this was the heading under which an extensive research
was applied, resulted by the presenting of powder coating (100% solid paint, consist of a homogenous mixture of
binders, pigments and additives) in mid-50's.
The actual launch for powder coating was in the 80's, where powder coating became the fastest growing industrial
coating worldwide.
World Production MTon
1972 44 500
1985 95 000
1992 350 000
1995 500 000
2000 F 780 000
Table 1: Powder Coating Production
1-Benefits of Powder Coating
*Quality: A superior consistence and uniform finish without sags, drips, or bubbles accompanied by high mechanical
and chemical resistance properties.
*Environmental: No VOC (Volatile Organic Compound) emission, which means that conservation of material without
polluting environment.
*Economical: -One step coating
-Less skilled labor needed
-High efficiency (95 %) 1 Kg Powder = 2.5 Kg Liquid Paint
Benefits of powder coating can be summarized in 5E's-Environmental compliance, Energy savings, Efficiency, Excellence
of finish, and Economy
2-Powder coating time line:
Late 1940s flame spraying of thermo-plastic powder
1953-1955 Dr. Erwin Gemmer develops fluidized bed application.
1962-1964 Electrostatic powder spray process introduced
1966-1973 The four original chemistries-epoxy, hybrid, polyurethane, and polyester TGIC were introduced and become
commercially available.
1970-1985 Rapid growth for powder coating spread throughout the world
1985- above Powder coatings became the fastest growing industrial paint
3- Powder coatings materials:
In general Powder coatings are a homogenized mixture of number of raw materials that can be divided into four
major groups
1- Binders: Which represent the body of the coat and responsible for its mechanical and chemical properties. It
is composed of two reactants (Resin and hardener), which when subjected to heat starts to react to form a longer
chain polymer in solid form i.e. the coating film.
2- Pigments: Which when used in the correct concentrations will give the requested color
3- Fillers: used mainly as extenders
4- Additives: (The spices of the recipe) used to improve some requested behaviors and/or decrease some non-requested
behaviors within the manufacturing process or the coating application process.
4-Powder coating production:
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5-Powder coating application:
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Fig 2: powder application
6-Powder coating future:
Future developments in powder coating which are now under lab testing or pilot plant application for following:
- Less curing temp.
- U V and I R curable powder
- Wood, plastic and clay substrates
- Super durable powder.
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