Coating Services Types and Terms

Types of Coatings

• Air-dried coatings, including forced-air dried coatings, are those which are not heated above 194ºF (90°C) for coating or drying.
  
• Air spray techniques 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.
  
• Baked coatings are heated to a temperature of 194ºF (90°C) in order to cure or dry them.
  
• Chemical vapor deposition (CVD) 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.
  
• Chromate conversion coatings have good corrosion resistance and provide a good base for paint or rubber bonding. However, chromate conversion coatings have little to no abrasion resistance.
  
• Conformal coating 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.
  
• Dry film coating 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.
  
• Electrocoating, 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.
  
• Electroless nickel plating 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.
  
• Electrostatic spraying 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.
  
• Hot melt coating 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.
  
• Ion-plasma coatings are very dense and are highly wear- and corrosion-resistant.
  
• Laminating 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.
  
• Liquid paint coatings 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.
  
• Manganese phosphating 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.
  
• Metal coating 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.
  
• Metal finishing removes surface to produce a flat, even surface.
• Passivation 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.
  
• Phosphate coatings chemically convert the surface of a base metal into a non-metallic, crystalline coating.
  
• Physical vapor deposition (PVD) 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.
  
• Plastic coating 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.
  
• Powder coating eliminates the need for polishing by applying dry paint to a component.
• Teflon (polytetrafluorethylene) coatings are utilized for such items as cooking utensils and other industrial applications, because of the non-sticking characteristic of Teflon.
  
• Thermal spray coatings 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.
  
• Thin film coatings, which include physical vapor deposition (PVD) and chemical vapor deposition (CVD), are use predominantly in the manufacture of electric devices.
  
• Vacuum coating 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.
  
• Zinc phosphate coating 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.

Coating Services Terms

Adhesion - The strength of the coating bond to the substrate. Some techniques for measuring adhesion include the tape test, scratch adhesion test and stud-pull-off test.
 
Adhesive Applicators - Tools used to apply an adhesive or bonding agent, including squeeze bottles, pressure tanks, glue guns and coating machinery.
 
Binder - A non-volatile material, commonly a resin, in a coating that forms a film by binding the pigment and additive particles together.
 
Biocide - A chemical agent, sometimes added to waterborne coatings, which prevents microbial degradation by killing the organisms that cause it.
 
Bituminous Coating - A compound made from tar or asphalt that provides a protective finish for a surface.
 
Coating Applicator - A machine used to apply defect-free films to products. Factors that affect the quality of the coating include line speed, viscosity and percent solids.
 
Cohesion - The ability of a substance to adhere to itself. When delamination occurs within a material, it is referred to as cohesive failure.
 
Delamination - Also known as "cohesive failure," it is the separation of a coating from its substrate. Delamination can also refer to the division among multiple coating layers.
 
Hylar - A material that is quite stable when exposed to harsh environments and is applied to such products as semiconductors, chemical processing, wire, cable, piping and tubing. Hylar is useful in the preparation of corrosion-resistant coatings for chemical process equipment and durable decorative finishes on building panels, due to its ability to be dissolved at high temperatures in certain polar solvents, such as esters and ketones.
 
Insulbar - A glass-fiber, reinforced polyamide nylon material that provides superior insulation, strength and durability, especially on windows.
 
Kynar - A material used in coating applications to provide high mechanical and dielectic strength, thermal stability and abrasion, chemical and solvent, UV and radiation and weathering resistance. Kynar coatings have been used as pipe liners in chemical processing plants, on equipment that is constantly exposed to high concentration of chlorine and chroline dioxide, typically in paper and pulp processing plants, and in silicon microcircuit fabrication.
 
Parylene - An atypical polymer conformal coating that conforms to almost any shape.
 
Substrate - The material that is being coated.
 
Scratch Adhesion Test - An adhesion test for coatings that normally uses a diamond stylus to apply a force to the coating. The test is affected by factors that include the substrate material and its hardness, the geometry of the part and the thickness and hardness of the coating.
 
Stud-Pull-Off Adhesion Test - An adhesion test in which a stud containing a head with a specified surface area is epoxy-glued to the coating. A machine pulls on the stud with amplifying force until it is pulled off.
 
Tape Adhesion Test - An adhesion test in which a certified tape is adhered to a coating and removed. If any coating is observed on the tape, it is a sign of an adhesive problem.