4th April 2024
Polyester powder coating has a long history. Originally created as a means of coating cars in the automotive industry, it was later adopted by the industrial world as an affordable and efficient way to paint and protect metals. Today, its use is widespread, making it one of the most important polymers in modern industry.
Now, powder coating is used in industries ranging from maritime to manufacturing. It is still used to protect metals, but it is also used to coat them in a range of colours. The powder coating process has adapted over the years, going from being applied with electrolyzed spray guns to being turned into a liquid in a fluidised bed. Here is everything you need to know about the history of polyester powder coating, and how dry powder is being used today.
When Did Powder Coating Start?
Polyester powder coating began as a way to protect vehicles from the weather and other elements in the automotive industry. Today, it is used on everything from bridges to household appliances, and its versatile nature has made it a popular choice among artists and designers.
The first polyester powders were made from polyester resins. As part of the powder coating process, these powders were applied to metal surfaces using electrostatic spraying, a process where powder particles are given an electrostatic charge before being sprayed onto the surface of a metal that is earthed.
Polyester powder coating became popular due to the many advantages it had over liquid coating, which was the method that was traditionally used in the 1950s. For example, polyester powder coating is more efficient and cost-effective than liquid coating. It is also more environmentally friendly than liquid coating, as it does not release large amounts of volatile organic compounds (VOCs) into the air (though at the time, this wasn’t a major concern).
Today, polyester powder coating is considered a reliable coating method that offers excellent durability and corrosion resistance, making it a popular choice in many industries.
What is Fluidized Bed Coating?
Fluidized bed coating is an alternative coating process where a metal product is dipped in a chamber. This chamber is then filled with dry powder, and a stream of hot air is blown through it, causing the powder particles to become suspended in the air and behave like a fluid.
Metal products can then be dipped in this chamber. The dipped product will then come out completely covered in powder. Think of it like dipping an item in a tub of paint. This is used in the coating industry to coat items that are awkwardly shaped, like a metal basket, for example. A fluidized bed means that a polyester powder coat is applied to all the little nooks and crannies that are easily missed with spray guns.
Powder Coating Facts
If you want to become a guru in the coating industry, then here are a few fun facts that you need to know about dry powder and the polyester powder coating process.
Fact one: Powder coating is primarily used for corrosion resistance.
Fact two: When applying powder coating, it works best when applied to a surface that has already been smoothed by shot blasting. Shot blasting removes any rust, grime or debris from the surface of a metal.
Fact three: The particle size of powder can be as small as 5 microns or as big as 120 microns.
Fact four: The fluidised bed process was discovered in 1960.
Fact five: British Standard Powder Coating (BS EN 12206) sets the minimum coating weight that can be applied to a given surface.
