by Jim Kerr
Atomic Force Microscopes. Nano-particles. It sounds like science fiction adventure instead of paint technology but nano-technology has been utilized in paint clear coats on several models of Mercedes-Benz cars since the end of 2003. To become the world’s first car maker to offer this paint technology, Mercedes-Benz spent over four years of development and testing, producing a new clearcoat that has improved chemical and scratch resistance. It all begins with ceramic particles measuring a millionth of a millimetre each.
Nano-technology was first introduced in 1959 when the renowned US physicist and Nobel Prize winner Richard Phillips Feynman developed the basic idea. It wasn’t until the mid 1980’s that the invention of the Atomic Force Microscope allowed researchers to delve into the actual nano-cosmic world. For the first time in 1989, researchers managed to move atoms around at will and this is now leading to new developments in medicine and mechanical technology just to start. For example, nano-technology has allowed the development of the world’s smallest nozzle, a thousand times thinner than a human hair.
When developing paint clearcoats, the mass and available surface of nano-particles are insignificant in relation to their adhesion, allowing them to stick soundly to any surface. They are perfectly suited as extremely thin coatings on conventional materials, which they make less susceptible to breakage and more scratch-resistant.
During the paint process, the ceramic nano-particles float around freely in the liquid paint. When the car body is baked inside the paint shop oven at 140 degrees Celsius, the ceramic nano-particles cross-link into a dense network instead of the long molecular chains found in conventional paint. This allows the lacquer to provide much more effective scratch protection against normal wear and tear.
Testing of nano-particle clearcoats shows they are three times more resistant to fine scratches than conventional clear coats and this allows the paint to retain its gloss. Mercedes engineers noted an around 40-percent improvement in retaining paint gloss compared to conventional clear lacquers.
The Mercedes-Benz engineers also noted that a large proportion of all paintwork scratches are caused by mechanical car-washes. Minute particles of hard materials, such as road dust and sand become lodged in the rotating brushes and etch scratches into the paint surface. These “hair scratches” are particularly noticeable in darker paint shades. To reduce the amount of scratching, the experts at the Stuttgart-based vehicle manufacturer have the following tips for passenger car owners:
* To avoid scratches caused by sand, dust or other miniscule particles on the surface of the body, a thorough pre-clean is recommended. Therefore, always spray the paintwork down with the high-pressure washer before driving into the automatic car-wash. (I prefer the touchless car washes myself.)
* After the car has been washed, dry it off with a cloth in order to avoid water stains on the paintwork.
* Remove insect remains, tar marks and bird droppings as quickly as possible, as they can damage the paintwork if allowed to dry. These kinds of marks and stains can usually be removed quickly and easily using a sponge and lots of water. When it comes to tar marks, use a special tar remover cleaner. After cleaning the affected areas, polish them with a soft cloth.
* Car owners should apply preserver to their vehicle’s paintwork twice a year. You can gauge whether this is necessary by carrying out a simple check: if the water no longer beads on the surface of the car body after it has been washed, then action should be taken. For older vehicles with dull paint, a high-quality polish is the best option. In the case of newer cars, a gloss preserver should be sufficient. Like polish, this should be applied extremely thinly and in circular movements using cotton wool.
If the paint has lost its lustre, the experts recommend an intensive treatment, ideally using special polishing machines. First paint cleaner should be used to brighten up matt paint, then polish applied to restore a gleaming finish. Here again, gloss preserver ensures a lasting sheen.
If your car has the nano-particle paint technology and you happen to be involved in a collision, this new paint technology can be duplicated by local bodyshops using Mercedes-Benz approved methods and paint materials. The biggest change in paint application is the drying process, which is more important than with usual clearcoat to ensure that the final results are as intended.
Nano-technology is just in its infancy. Already the engineers in Stuttgart are looking at the self-cleaning ability of nano-particle surface structure for automotive wheels. Perhaps in the future, your car will even be able to clean itself!