When a powder coating is applied on surfaces other than classical metal substrates, a challenge rises. The low surface electrical resistivity of the thermoplastic olefins (TPOs) used for automotive fascia, dashboards, cup holders, door coverings, and roofing material must be modified with conductive adhesion promoters to improve electrostatic coating efficiency. Usually, carbon black or metal dust are used to enable conductivity in primers. However, they negatively affect the paint’s basic properties and limit the range of available colors. 

A solution has been proposed by Clear Skies Coatings, a manufacturer and supplier of premium paint coatings to the automotive industry. The company offers an advanced conductive primer and adhesion promoter for TPO substrate. A colloidal suspension of powder in water enhanced with TUBALL™ COAT_E H₂O 0.4%, a water-based dispersion of graphene nanotubes that is commercially available from OCSiAl.  

David Detzler, Clear Skies Coatings president, explains, “our Ad-Pro Zero patented formulation is made of a chemistry for powder coat. It is a conductive, sustainable, and durable gray-colored coating that combines the benefits of the traditional liquid adhesion promoters and conductive primer with the performance of powder coatings. It enables an easy and clean application on temperature-sensitive materials such as TPO and wood. The automotive sector is highly sensitive to this combination of benefits; our new solution is being assessed by TIER-1 in the United States.”    

Containing less than 0.05 wt.% of graphene nanotubes, the formulation features a gray color and can be coated with a thickness as low as 0.3 mil, while achieving a surface resistivity <10⁵ ohm/sq. Applied on thermoplastic car parts, the new product strongly improves the adhesion of the clear coat, making possible to reducing its thickness, and enables a wide spectrum of color shades.     

“This new coating with our graphene nanotubes is a revolutionary promoter for TPO-based car parts that has high performance, zero emissions of volatile organic compounds, zero hazardous air pollutants, and no halogens. For after-market facias, this powder slurry can be used as an ad-pro at about 6 to 8 microns,” said Ian Fellows, CEO, OCSiAl USA.

The new graphene nanotube solution has enormous potential in the automobile and wood industries, which will benefit from the increased cost efficiency, long-lasting performance, and the ability to eliminate harmful emissions.