|
Information Page Links:
Featured Coating Services Providers
About Industrial Coatings
Coating Services Terms
Coating Services Associations
Coating Services Resources
Trade Shows
Featured Coating Services Articles
More Articles
|
|
About Coating Services
Industrial coating services are necessary for applications
in which thin films or coats made of varying materials are applied to
substrates. Industrial coatings processes include solution preparation
and delivery to applicator, the coating application itself and drying
and solidification. In the first step of industrial coating, raw material
is specified and tested, deaerated, mixed and dispersed. Then, fluid
flow, weight and measurement of the coating are determined. Certain substrates
will only be compatible with particular coating materials. The final
drying and solidification process includes heating and ventilation systems
and heat transfer and defect mechanisms.
There are several different methods of industrial coatings. Dip industrial coating
is the most widely used method for coil coating but is also used for other products.
In this process, the part is completely assembled and then submerged into either
a solvent- or water-based coating. Dip coating encompasses electrodeposition
(“E” coat), liquid, epoxy, phenolic, enamel, acrylic and alkyd coatings.
Electrostatic coatings are either negatively or positively charged and are applied
to a substrate with the opposite charge. These coatings provide excellent adhesion
and corrosion resistance but require a multi-stage cleaning process. Electrostatic
coatings include phenol, enamel, acrylic- or alkyd-based resins and powder
coatings. Conversion coatings are produced by a chemical reaction between
the base metal and another material, which forms a fairly corrosion-resistant
film.
Industrial coating services are necessary for a variety of reasons. Some industrial
coating services provide protection against corrosion, thermal fatigue and oxidation.
Other industrial coatings reduce heat transfer or dissipate heat, decrease friction
and retain or shed chemical petroleum products. Extremely versatile water-reducible
alkyds are so named because they can be thinned to almost any viscosity and are
suitable for dip or spray applications. Acrylic powder coatings provide excellent
chemical, corrosion and scratch resistance and have superior hardness and overall
durability. In a fully cured state, fluorocarbon is very hard and resistant to
chemicals, solvents and sunlight. Powder polyester coatings are highly flexible,
durable and resistant to UV radiation and have good weatherability. Polyethylene
powder coatings are easily-cleaned thermoplastic power coatings that are used
for thicker coatings and to provide resistance to acids, alkalies, salts, alcohols
and solvents.
Industrial coating service providers will need to know several things before
recommending the industrial coating that is appropriate for the product. The
main factor is application, i.e. the key benefits and coating attributes that
are desired from the industrial coating. Often times, coatings are asked to perform
multiple functions, so the industrial coating service provider may ask for a
list of desired attributes in the order of importance. What are the operating
conditions of the part and what is its life expectancy? It is also important
to know what alloys are in the part and what processes it has undergone (e.g.
heat treatment). Are there tolerance and other rigid specifications that must
be adhered to? Industrial coating service providers might also ask what coatings
or processes have been tried in the past and if price is a primary factor.
Featured
Articles
http://www.imagineering-inc.com/solutions/phosphate.htm
http://www.imagineering-inc.com/white_paper/en.pdf
http://www.imagineering-inc.com/white_paper/passivation.pdf
Types of Coatings
- ,
including forced-air dried coatings, are those which are not heated
above 194ºF (90ºC) for coating or drying.
-
utilize compressed air to spray liquid coating through a small opening
at high pressure. The materials are not mixed with air before being
sprayed through the nozzle.
-
are heated to a temperature of 194ºF (90ºC) in order to cure or dry
them.
- is a thin-film coating process that produces a film by
a chemical reaction. CVD processes often use unstable elements to coat
cemented carbide inserts.
- have good corrosion resistance and provide a good base
for paint or rubber bonding. However, chromate conversion coatings have
little to no abrasion resistance.
-
is a process in which dielectric coating, such as epoxy, urethane, parylene,
acrylic and silicone, is sprayed onto a substrate. Conformal coatings
are used to protect products from fungus, moisture, abrasion, corrosion,
etc.
-
is a lubrication process that helps to prevent scuffing and galling,
reduces friction, provides extra protection by preventing damage from
oil film failure and aids in the distribution of heat, resulting in
less metal fatigue, which reduces the chance of part failure. Dry film
coating does not cause any dimensional changes to the product to which
it is applied, because it is impregnated directly into the metal surface.
- ,
also known as “electrodeposition,” “electrophoretic
deposition” or “electropainting,” is a process that
resembles electroplating, in that it uses an electric current to apply
thin-film primers and one-coat finishes onto the metallic substrates.
However, this organic finishing process does not deposit metal ions
onto the substrates, but rather, waterborne paint.
- is a quick, easy, economical chemical reduction application
process that avoids the use of electrolytic energy. Electroless nickel
plating is ideal for small parts, provides an even, uniform layer, leaves
no anode shadow, does not pose disposal problems and can be applied
to many metals, including all steels, irons, copper, brass, bronze,
lead free solders and nickel alloys.
-
is a process in which the paint is given a negative or positive charge
before it is sprayed and the workpiece is oppositely charged, resulting
in the attraction of the paint particles, uniform dispersion and reduction
of waste. Electrostatic spraying, which is well-suited to automation
because it increases production rate, reduces corrosion, protects against
scratching, stops contact with air, water, chemicals, etc., alters appearance
of workpieces and gives good finishes.
-
is a method used to apply plastic materials to a substrate. Hot melt
coating is frequently used on papers and books and does not necessitate
the use of solvents.
-
are very dense and are highly wear- and corrosion-resistant.
- is
a process by which a plastic transparent film is applied to one or both
sides of a product. Most frequently used for paper products, the laminate
enhances both decorative and protective qualities.
-
are applied by spraying—atomizing the paint into a fine mist—and
depositing the mist on the surface of the part, where the tiny droplets
flow together to form a film. Liquid paint coatings are available in
a wide variety of colors and contain binders, solvents and pigment.
-
is a coating process that is used in the pretreatment of iron and steel
surfaces prior to painting, especially military equipment that requires
oil or greased paints. Manganese phosphate coatings are highly corrosion
and wear resistant.
-
is the application of a thin or series of thin coats of any of various
metals. Some types of metal coatings include electroless
nickel plating, phosphate and chromium.
- removes surface to produce a flat, even surface.
-
is a process that removes excess iron molecules from the surface of
stainless steel products, typically with the use of nitric acid solutions.
The danger of rust then becomes negligible.
-
chemically convert the surface of a base metal into a non-metallic,
crystalline coating.
- is a thin-film process in which a material is placed inside
a vacuum chamber and vaporized. The atoms are transported across the
chamber onto the substrate and condense into a film on the substrate.
-
is a layer of plastic material that is dried on top of a substrate.
Plastic coating is ideal for odd shapes and when materials need to be
coated entirely.
- eliminates the need for polishing by applying dry paint to a component.
- are utilized for such items as cooking utensils and
other industrial applications, because of the non-sticking characteristic
of Teflon.
-
are typically zinc or aluminum and are heated until liquefied. Liquid
drops are then blown by means of a compressed air jet onto the substrate,
creating a porous coat.
- ,
which include physical vapor deposition (PVD) and chemical vapor deposition
(CVD), are use predominantly in the manufacture of electric devices.
-
is a process in which the coating material is applied in a vacuum chamber
to the substrate. Usually the material is vaporized and then transferred
through a chamber to the substrate.
-
is a paint pretreatment that is commonly used to develop good bonding
qualities between the paint and the galvanized or galvannealed coatings
on steel sheets and is applied while the steel is in a coil, to the
cut sheet or to the fabricated article. Zinc phosphate coatings greatly
aid paint adhesion, in that they dramatically decrease the tendency
for paint disbondment during subsequent atmospheric exposure in a corrosive
environment.
|
|