Polyester powder coating is a dream come true for metal manufacturers. It’s a process that protects metal from environmental damage, increasing its lifespan and resulting in higher-quality metal products.
Understanding how polyester powder coating works will help you to understand how it can be used to protect your metals. It will help you to understand why a powder coating finish is so important if you want products that impress your customers by withstanding rust for many years.
The Industrial Powder Coating Process
Powder coating is an industrial process which is used to protect metal from moisture, which causes rust and corrosion. Alongside damaging metal, rust and corrosion are also unsightly, and not something customers want to see if they’re investing thousands into steel products, like intricate balconies.
The process starts by preparing the metal. This is achieved with abrasive blasting. Abrasive shot blasting involves firing steel shot or abrasive blasting grit from a gun at metal to prime its surface. This abrasive blasting should be complete to a SA2.5-SA3 Standard.
Once the metal has been primed, you’ll want to add a protective seal. This can be hot zinc spray, which coats metal in hot zinc using an arch spray gun. Alternatively, you can use hot dip galvanising to galvanise your metal. Hot dip galvanising involves dipping metal in molten zinc rather than using a spray gun.
You then add a top coat, the dry powder coat is added by a powder coater. The spray gun used to apply the powder coat is fitted with an electrostatic charge. This charges the powder as it passes through the spray gun. The item is grounded and the metal surface attracts the charged powder to stick to it.
The powder coated parts are then placed in a curing oven by the powder coater. The curing oven then has to hit a certain temperature before the powder will cure and the powder coated parts are removed from the oven by the powder coater. This process continues, and the metal is put in the curing oven again if the product needs more than one powder coat.
Powder Coating Process Steps
Below is a step-by-step breakdown of the powder coatings process.
Step one: Prime the metal with abrasive blasting to a SA2.5-SA3 standard
Step two: Add a protective seal, like hot zinc, which can be applied in a spray booth or galvanising tank or a zinc spray primer
Step Three: The powder coating top coat is applied
Step five: The metal which is now covered in the powder coating material is placed in a curing oven
Step six: Repeat this process if a second coat is needed
Powder Coating Process Temperature
Powder coating finishes need to be left in a curing oven until the oven reaches around 350-400 degrees Fahrenheit. This is the temperature that powder coating finishes need if they are to properly cure. The curing time is dependent on the metal composition and its thickness, as the metal needs to reach a specific core temperature in order for the powder to cure properly.
Experts in the Powder Coating Application Process
We’re so confident in our powder coating finishes at NSP Coatings that we offer our clients a 60-year guarantee.
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