While many people assume that powder coating is a new process, it has been around since the early part of the 1960s. The technology and options in protective powder coating have evolved over time, with multiple different options to suit specific requirements and applications.
The advantage of this option in coating metal is the use of a dry powder rather than a wet liquid. The problem with wet liquids is that it is very difficult to obtain an even dispersion and there is a greater risk of running or thickness irregularities. On the other hand, with dry powder coat applications, it is easy to control the thickness of the coating without these additional issues.
While it is called protective powder coating, it can also be used for decorative finishes as well. With a full range of colors and even the option for different textures, this is ideal as a primer or as a single coating option.
The protective powder coating is made from a polymer resin with pigment and specific additives to provide color and to allow the dry powder to flow onto the surface.
This very fine powder is placed in a spray gun, and then an electrostatic charge is applied to the powder. As it leaves the gun this electrostatically charged spray attaches to the metal part, which is grounded.
Once the surface of the part is covered with the powder, the part is then placed in a curing oven. This is a specific heat that is determined by the type of resin used in the powder coating option selected. The heating process changes the molecular structure of the coating, creating very long molecules that are extremely durable and resistant to any molecular breakdown.
For large items or high production, the process can also include pre-heating the parts and dipping them in a fluidized powder. Upon contact with the part, the molecular change occurs, creating an identical surface to the oven heating method.