Powdercoating Services in Sydney
Powdercoating is an organic coating method which uses a coating material in the form of a fine powder. The main difference between a conventional liquid paint and a powdercoating finish is that the powdercoating does not require a solvent to keep the binder and filler parts in liquid suspension form. This powder is applied using high voltage, electrostatic guns that impart a static charge to the powder, allowing it to stick to the components. The powder film is then baked at around 200°C, where it melts and the curing occurs, forming a paint ‘skin’ on the product.
The process is a very common finish and is used on all types of metal components from fencing panels and bike frames to light poles and car wheels.
For successful powdercoating, the part must be able to withstand the required curing temperatures of approximately 200°C and, like most coatings, the metal surface must be free from any surface contamination. Surfaces can be prepared for powdercoating by abrasive blasting and/or using chemical conversion coatings such as phosphates or the many other chemical surface treatments available. The part being coated generally must be electrically conductive, as it will need to be earthed to attract the electrostatically-charged powder.
Parts are most commonly hung on a rack or hook, which will leave a small mark somewhere on the component. As always, we endeavour to work with all our customers to ensure the rack mark is on a cosmetically minor or internal surface.
Powder has a number features that make it an attractive all-round finish. It has good covering ability, it emits very few volatile organic compounds, it offers a great range of textured and glossy finishes, and it exhibits strong chemical resistance characteristics.
The nature of the application process means that powder will tend to build up on the edges of parts where the coating thickness may be well over the 150 microns. Recesses and internal corners will show reduced thickness and in some cases may even be uncoated, due to the nature of the electrostatic charges.
Powder formulation can be based on polyester resins (which is the most commonly used general purpose powder), epoxies, polyurethane blends and even PTFE coatings.