New car paints designed to reduce rust and pollution
A technological revolution is under way in automotive paints. "The changes coming in automotive paints [both primer and final coat] over the next few years will be astounding," asserts Ernest O. McLaughlin, manager of paint processes for American Motors. AMC now is using high- solids enamels in five of its 14 jeep colors to reduce solvent hydrocarbon emissions in body-painting operations.
About 60 percent of the cars in the US now are produced this way and more are to follow. US air-quality standards will bar conventional automotive paints by the late 1980s. "By 1987," reports Mr. McLaughlin of AMC, "federal emission regulations will limit the amount of solvents to a level of 2.8 pounds for every gallon used."
AMC is building a new paint plant at the Jeep assembly site in Toledo, Ohio.
Further, special rust-fighting primer paints also are used on a worldwide scale.
A special process called cathodic electrodeposition is aimed at sharply reducing any proclivity of a car body to rust. Car bodies are dipped in a bath of paint particles which are suspended in a water solution. When electric current is applied, the positively charged paint particles are drawn to the negatively charged body, building a uniform primer film on all surfaces.
"In North America, about 60 percent of all automobiles, or more than 4 million this year, now are primed with the new process," reports Frederick F. Rhue, head of automotive finishes for PPG Industries.
Overseas, it will be used on another 4 million motorcars.
The new technology is now, or will be, used in West Germany, France, Japan, Italy, Australia, Spain, Britain, and some South American countries with automotive industries.
The process, according to Mr. Rhue, is proving so superior to other primer paint technologies that the severity of some standard corrosion test methods is being doubled.
As for the high-solid paint, Mr. Rhue states: "The automobile companies now are experimenting to be sure they can use these satisfactorily and not run into any problems." The two leaders in the use of high-solid paints are General Motors and AMC.
Less paint is required to achieve the same paint film thickness and better gloss than provided by conventional paints, says Mr. Rhue.
Powder paints were a big issue a few years ago but never went anywhere in the auto industry. While work still is going on in the area, it is mainly in other industries than automotive.
"The biggest problem is probably the ability to compete in appearance," according to Mr. Rhue of PPG.
Three primary factors are essential in automotive finishes: (1) cosmetic appearance; (2) showroom appearance; and (3) anticorrosion.
"The automotive companies are attacking all three," asserts Mr. Rhue.
Looking ahead, Mr. Rhue says the industry is shooting for 10-year protection on perforation rust and 5 years for the cosmetic appearance of a car.
"That's the goal," he declares. "That goal might be achieved within the next five years. We're going to have to change the paint facilities anyway, so we might as well look for products that are going to improve the quality of the cars."
"There's never been a time like this in the history of automotive coatings," concludes Mr. McLaughlin of AMC.