Powder coating is a dry medium, and as such it won’t cling to a substrate just by itself. Unlike liquid paint which will cling to a surface thanks to its viscosity and evaporating solvents, powder coating needs extra help holding on until it can be cured.
Electrostatic powder coating application helps with this issue, allowing the powder to hold onto whatever object it’s being applied to. Once the powder is heated this is no problem, but just how does this technique work in the first place?
Powder coating is applied using electrostatic spray deposition, or ESD. This means applying a charge to the powder particles that allows them to hold onto their intended substrate despite being dry.
This is highly useful as it means the powder gets to stay in its form without the use of any liquids or additional materials needing to be added, which could be mixed poorly or otherwise throw the chemical balance of the powder out.
This also allows powders to stay uncomplicated and suitable for heating without releasing the same harmful chemicals that paint does, such as volatile organic compounds—a key strength over paint that makes it so attractive in the first place.
Applying a powder coating with ESD involves the use of a spray gun that imparts an electrostatic charge onto the particles of powder as they’re sprayed. The spray guns have an electrode as part of their makeup that does the charging.
Meanwhile, the part being coated is grounded and suspended in the air. The charged particles are attracted to the neutral substrate and cling through electrostatic force. So long as the balance of charge isn’t disturbed on the part, it can then be cured to set the powder properly.
The vast majority of powder coatings are applied electrostatically, as it presents the most straightforward way to ensure the powder binds to its substrate until it can be cured.
The powder coating itself doesn’t require anything special to be given its charge, only that it’s applied using the right kind of spray gun that imparts the charge in the first place. This is beneficial as it also contributes to the recyclable nature of powder coating.
Any powder that doesn’t cling to the substrate and is left over can be collected and reused in future applications. Once reloaded into a spray gun and used, it will be given a new charge and can have a second chance at clinging to the neutral object being coated.
Our long-built experience and knowledge of applying powder coatings allows us to get them right every time and ensure each application is full and even. Smooth, uniform coatings are always our goal, and we’ve been delighting our customers with just that for many years.
To find out more about our powder coating services, contact us today.