An emission-free and environmentally sustainable automotive coating system has been developed by Australia’s CSIRO and Dulux Powder Coatings.

The Australian automotive industry uses about 10 million litres of liquid paint a year to coat the surfaces of new vehicles, including putting decorative finishes on plastic components, however, traditional wet paints have disadvantages. They do not have a high rate of spray transfer onto plastic parts – around 70 per cent is lost as waste, and contain solvents that release volatile organic chemicals (VOCs) to the atmosphere.

The goal of the project was to overcome a long-term sustainability issue for the automotive, plastics and furniture industries by replacing wet paint finishes on heat-sensitive substances, such as plastic components, with zero-waste powder coating technology.

Powder coating offers many advantages – almost all the powder ends up on coated plastic components, it contains no solvents, and there is no-flash-off time after spray application – which is essential for removing residual solvent from wet paint.

Powder coating particles are attracted to and stick very well to the material being coated, provided it conducts electricity. Powder coating relies on the powder carrying one type of electrical charge and the material being coated having the other: opposite charges attract so the powder sticks and is then cured to form a smooth finish.

The plastics used to make the automotive components in question are not conductive.

Together with partners, Dulux Powder Coatings, CSIRO developed a technology platform that enabled the replacement of wet paints with environmentally-friendly powder coatings when coating heat-sensitive substances such as plastics. 

CSIRO achieved surface conductivity by coating the plastic components with a nanometer-thin layer of specialty multifunction molecules that provide surface conductivity and promote the ability of the powder coating to stick well to plastic components.

Within this partnership, Dulux Powder Coatings developed a new generation of powder coatings that could be cured at much lower temperatures and for much shorter times than traditional powders.

The powder coating system has been successfully trialled in the Australian state of Victoria, and is now being customised for coating automotive plastics and is in demand by customer interstate and overseas.

The system has also won the 2008 Premier’s Sustainability Award for products of services.