Mazda Motor Corp. will begin transitioning to water-based paints at its global manufacturing facilities starting next year, with its plants in Japan the first of Mazda's to completely do away with solvent-based paints, officials say.

“We are developing the technology to apply water-based paint in our 3-coat (wet-paint) system,” which currently uses low-solvent paint, senior research engineer Takakazu Yamane tells Ward's.

The application of water-based paints in traditional vehicle-painting systems necessitates the use of air conditioning and pre-heating of the baking oven, both of which release carbon dioxide, he says.

Mazda's 3-coat system eliminates the baking of the primer coat before the base and clear coats are applied, thereby reducing CO2 emissions.

“Today, global attention is particularly paid to environmental issues,” Yamane says at Mazda's global headquarters in Hiroshima during a media presentation on the 3-layer wet-paint system, noting xylene and toluene solvents are the main volatile organic compounds emitted during the traditional paint-shop process.

Mazda's 3-layer wet system reduces VOCs by cutting the solvent content and by using less paint thanks to a new robotic system that offers greater movements than the standard reticulating system.

“(The new robotic system) can spray the required area as we want,” Yamane says.

The robotic system's transfer efficiency, the rate at which paint adheres to the vehicle and is not lost due to over spray, increases to 80% from 68% for the base coat and to 85% from 79% for the primer and clear coat. Efficiency also is improved in coating the interior of the vehicle with the new system, Mazda says.