E-coat technologies and where they fit: cationic and anionic technologies continue to grow in both the automotive and general industrial markets. Auto frames, engine cradles, radiators, fasteners, HVAC, agriculture, and lawn and garden are some of the growth areas.

Electrocoat has been used for years in the automotive and industrial markets. But in the years since its introduction, new E-coat products have been developed for end uses requiring different properties, such as UV resistance, low-temperature cure, and corrosion and UV resistance combined with bulk application.

The Ford Motor Co. first used anionic E-coat to paint steel wheels and automotive bodies. Ford wanted a primer that could be applied uniformly over the entire surface and provide improved performance. At the time, most primers were applied by spray application, which was not able to apply a coating into the recessed areas of the car body with consistent coverage. The E-coat process allowed the entire body to be uniformly coated in about two minutes.

After many years of development work, cationic E-coat was patented and commercialized in 1971 by PPG Industries. The appliance industry became the proving ground for the new E-coat process. Washing machines and dryers were primed with a low-film-build cationic epoxy coating that withstood the rigors of detergent testing and provided the manufacturer with a controlled film build and a corrosion-resistant product in a short application time.

The automotive industry began testing this new product and soon found that corrosion performance could again be improved. In 1976, the automotive industry followed the appliance industry and began using cationic epoxy E-coat technology.

Expanding markets

In the 1980s, the automotive industry began using high-film-build systems, which applied a thicker coating of E-coat and eliminated the need for the primer surfacer. This improved process time and provided a more uniform substrate for the top-coating process.

This decade also saw the introduction of cationic acrylic technology. Once only available in the anionic process, cationic acrylic technology provided excellent outdoor durability. Applications that required durability properties could utilize the processing improvements that E-coat provided.

In the 1990s, the technology continued to develop, but was pushed by environmental concerns over VOCs and …