Paints, Powder Coating, and Specialty Coatings

RIE can help you determine which type of paint is suitable for your particular application.

Single component paint is usually composed of the pigment, an organic vehicle (the base) to suspend the pigment and provide structure, and a solvent to thin the paint to an applicable viscosity. This type of paint cures by the evaporation of the solvent from the applied paint. Examples are latex paints, oil based enamels, lacquers, baking enamels and acrylic enamels.

There is a type of single component polyurethane that relies on elevated humidity to properly cure, contrary to common intuition. Water hydrates the material, chemically bonding with the base causing it to fully cure. This paint is typically low outgassing and is used in space or high vacuum atmospheres.

Multicomponent paint, is comprised of the pigment, the base, a catalyst (or hardener), and a solvent. The difference here is that the paint will not fully cure by the evaporation of the solvent only, but rather relies on the chemical reaction between the base and the catalyst(s). The function of the solvent remains the same. Some common paints of this type are epoxy and polyurethane.

There are many special chemical formulations for paints: acrylics, latex, epoxy, polyurethane, among others, and the type of paint to be chosen depends on the client’s application.

A great leap in paint technology came about forty years ago with the development of dry painting – or powder coating.

Gun manufacturers are one of the sectors we serve in our powder coating division with firearms coatings such as Cerakote™.
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The paint itself is in the form of a very fine dry powder. It is applied either electrostatically with very specialized spray equipment, or in some cases using a fluidized bed where the part is heated and passed through a “cloud” of the powder.

After the powder is applied to the part, it is baked in an oven (typically 350-400oF) for a sufficient time to cure the powder. Infrared light (IR) can also be used to cure the powder but is primarily limited to flat surfaces.

Since the curing temperature is elevated, until recently metals were the only material suitable for powdercoating, although ceramics and similar material could be powdercoated if pre-heated.

Recently there has been success by some manufacturers in powdercoating wood using specially formulated fast low temperature curing powder and IR.

As with wet paint, there are many different formulations of powder, each having unique advantages or disadvantages under differing exposures.