Mercedes-Benz M-Class Paint
R-Class concept debuts with new alu-beam finish
Mercedes showed the R-Class concept at the North American
International Auto Show in January 2005 with the new
alu-beam paint. The paint looks similar to polished aluminum,
creating a mirror like reflection, and was applied in "steel" tone.
The pigment particles are nanometers in size,
smaller than in metallic paints, creating the realistic metal finish
effect. The background might be the titanium panels on the Guggenheim
Bilbao, by Frank Gehry.
Glasurit Velvet Silver II Metallic
Standox AluShine
Verde Brook Metallic
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2006 Mercedes M-Class paint color translated
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M-Class FrameCoat electrodeposition coating receives PACE award
The W163 M-Class uses PPG FrameCoat instead of the alternative
hot-wax products. PPG received the PACE innovation award for this
technology. It was first introduced by Ford in 1999 and garantees
10 years of rust protection. FrameCoat is a patented cathodic epoxy
electrocoat with several improvements over previous generations
including excellent corrosion resistance without the use of heavy metals.
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1998 to 2005 Mercedes M-Class paint color translated
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Mercedes-Benz Scratch Resistant paint
Mercedes utilizes several suppliers for their scratch
resistant paint, sometimes referred to as nanopaint. One
is CeramiClear from PPG in Pittsburgh, Pennsylvania, and
the other ProGloss from BASF Coatings in Münster. These
paints use very different chemistry. CeramiClear is a
polysilicate clear coat polymerising on the surface into a
very hard surface. The hardness prevents scratches. PPG points
out this is the only one employing nano technology.
ProGloss is instead based on a two component isocyanate
clear coat into which an acrylate is polymerised. It integrates
into the Glasurit chemistry, the 55 Line, a low VOC polyester based
paint system, or the latest 90 Line of low VOC water based paints,
which are widely used in Europe and also already in Vance, Alabama,
thus allowing a seamless transition. The surface is softer with
high surface elasticity and
reflow which also improves adhesion and reduces pitting from pebbles.
Reflow makes tiny scratches disappear with heat, like direct sunshine.
In contrast to the solventborne isocyanate two component clear used
for the M-Class since 1998 this new two component clear can also be
waterborne, since the aliphatic chains slow the decomposition in
water when premixing in the application bell nozzle.
For refinishing HS Clear Scratch resistant 923-45 VOC 3.5
(HS-Klarlack Kratzfest VOC 3.5) was introduced.
Spies Hecker and Standox offer scratch resistant clear
for refinishing as well, also with reflow properties.
Scratch resistant refinish clear coats
Glasurit HS Clear Scratch resistant 923-45 VOC 3.5 (reflow)
PPG Clearcoat CeramiClear D8126 (nano particle)
Spies Hecker Permasolid® HS Diamond Clear Coat 8450 (reflow)
Standox Standocryl VOC Platinum (part # 16161) (reflow)
Scratch resistant paint can be recognized by the C preceding the paint code. The paint in this picture has code 197 without scratch resistant clear coat.
This label shows C816 indicating a scratch resistant clear coat was applied. For refinishing PPG offers CeramiClear Deltron part numbers D8126, a VOC compliant high solids CeramiClear clear coat.
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This older article describes the paint system at MBUSI when they still used conventional clear coats. Total Source from Industrial Paint & Powder Magazine... Mercedes Explores New Territory Lead-free E-coat and a pendulum conveyor are just two of the "firsts" at the automaker’s new U.S. plant. Jane Bailey, Editor, IPP, (via PPG) For a conservative company with a reputation for quality, Mercedes-Benz certainly went the extra mile when building its first plant outside of Germany. Among the "firsts" at the $300 million Tuscaloosa, AL, facility are a lead-free E-coat and a pendulum-design conveyor for pretreatment and E-coat baths. The plant was built specifically for Mercedes’ new entry into the sport utility vehicle market—the 1998 M-Class model. Many of the innovations in the plant came from Mercedes’ desire to be a good environmental neighbor. "From the beginning, Mercedes established a goal to be environmentally conscious," says Bill Bugg, Mercedes’ manager of plant production. At the forefront of the environmental innovations is the coatings system, starting with the E-coat. The 60,000-gallon E-coat tank contains a lead-free cathodic epoxy coating from PPG Industries (Springdale, PA). According to Tom Palaika, PPG’s director of automotive coatings technology, it was the first lead-free automotive body E-coat tank in North America. Lead-free E-coat is not new to the industry, having been used for over 10 years to protect general industrial and automotive parts. But until recently, lead in E-coat was considered necessary to give auto bodies the required corrosion protection. Because of a growing concern about the toxicity of lead, coatings suppliers have been working to improve lead-free formulations to offer the necessary corrosion-protection. "In the latest formulations, the resin gives the necessary rust-inhibitive properties," Palaika says. "The newest E-coat formulations offer performance equivalent to former E-coats that contained lead." Mark Warner, environmental engineer at Mercedes, says the main impetus to go to a lead-free formulation was to reduce hazardous waste. "Traditional E-coat with lead causes hazardous waste problems, both in waste-water discharge and filter disposal," he explains. Not only is the new E-coat nontoxic, it’s also low in VOCs. PPG’s Enviro-Prime E-coat contains less than 0.5 pound of VOC per gallon. "The whole concept in designing this facility was to go the extra mile with environmental compliance," Warner says. "This E-coat is over 99% VOC free, and all our ovens are equipped with VOC-control devices, including the E-coat oven." The other coatings used at the plant are also environmentally compliant. The acrylic waterborne primer from BASF (Southfield, MI) is about 20% cosolvent and 80% water, according to Warner, and is also low in hazardous air pollutants (HAPs). Two primer colors are used: white for white cars, gray for everything else. "I’m not a big believer in colored primers," comments Jerry Pizzato, assistant manager of paint engineering. He says Mercedes chose waterborne coatings because of their success at the company’s German facilities. Mercedes went with a waterborne basecoat from BASF as well. Containing only 1 to 1.5 pounds of VOC per gallon, the acrylic-enamel basecoat is run in seven colors, with an expected increase to 10 by next year. Although silver metallic is the most popular, black, white, red and green are also offered. Less popular but distinctive is a translucent, opalescent coating called "black opal metallic," which appears either dark, charcoal black or purple, depending on the viewing angle. A smaller number of bright blue models are shipped to Europe. Using waterborne primer and basecoat brings another environmental benefit for Mercedes: solventless line flushing. "For the waterborne coatings, water is the best purge solvent. We use even more water in the purge than in the coating itself," Warner says. "It’s almost like a backwards environmental problem. The solvent from the purge can be used for energy recovery, but the water from the purge has to be treated. We’re still looking at treatment options." The clearcoat, a two-component isocyanate from BASF, is the only solventborne coating used at the plant. Warner says its VOC level is low enough to ensure compliance with federal Best Available Control Technology (BACT) guidelines and local regulations. To design the paint shop and address VOC abatement, Mercedes engineers teamed with turnkey systems supplier Dürr Industries (Plymouth, MI). The plant has a three-tower afterburner that controls all ovens and a two-tower unit that controls the clearcoat automatic application zone and primer flashoff. "The second unit was not needed to meet permit limits, but we chose to run it anyway to handle our solventborne coating," Warner says. All paint sludge is recycled, even though it could be landfilled. "It’s about 10 times more expensive to recycle, but we do it anyway," Warner says. The recycled sludge is used as a raw material for things like cinderblocks and roof tiles. Conveyor design improves quality. Besides its many environmental innovations, several design elements are unique to the Mercedes plant. To transport the car bodies through the pretreatment and E-coat systems, Mercedes chose a pendulum conveyor, rather than a traditional overhead power-and-free. The pendulum design is more familiar to European manufacturing plants, where land is at a premium, but is a new concept in the United States. "The first one I’d seen before coming here was at Saab in Sweden," Bugg says, adding that Mercedes had been using the pendulum design at its German facilities and wanted this cost-saving feature for its first U.S. plant as well. The pendulum conveyor is built on a 45-degree angle, vs. a 30-degree angle for a typical power-and-free. "The steepness of the pendulum design helps shrink the facility," Bugg explains. The result is a shorter conveyor and smaller dip tanks. The pendulum design also improves drainage and reduces chemicals, bath size, pumping capacity and energy usage. With the pendulum conveyor, auto bodies are picked up by a "cradle" carrier skid and transported through the tanks. The design of the pick-up shoe ensures a constant force between the pendulum electrode and the skid, resulting in a constant film build in the E-coat tank. Loading and unloading are automatic. The lack of overhead conveyor parts minimizes contamination. "I really like the pendulum conveyor from a quality standpoint. We don’t have as many problems with drips," Bugg says. Other plant innovations Mercedes uses a nine-stage pretreatment system to thoroughly clean car bodies prior to E-coat. The first two stages are double-dip degreasing tanks. "The double dip is fairly new to the industry," Bugg says. "Usually you just have one large dip tank." The two cleaner stages are followed by two city-water rinses, conditioner, zinc phosphate, two more city-water rinses, a deionized water dip and final virgin DI permeate spray rinse. Chemicals are supplied by Henkel Surface Technologies (Madison Heights, MI). From pretreatment, car bodies are transported to an open-air area via roller-bed conveyance, then back to another pendulum conveyor to go through the E-coat line. After the E-coat rinses, bodies are cured, inspected and sanded.
The primer coating is applied automatically by paint bells from Behr Systems (Auburn Hills, MI). Three bells are located on each side of the booth and three overhead. Warner says the bells offer very high transfer efficiency—about 77%—which helps Mercedes’ environmental efforts. The Behr application equipment relies on computer-aided design (CAD) images from Robcad, a three-dimensional simulation tool, for its programmed path. This is the first time in the United States that this technique has been used to program paint application equipment. Using Robcad, a paint engineer enters parameters such as desired percentage of paint overlap, vertical length of stroke, horizontal duration of stroke and number of locations per stroke. Robcad calculates a two-dimensional paint path. The engineer projects this 2-D grid onto the model of the car. The paint path can then be attached to the car, so the paths move as the car comes down the conveyor. Data such as "gun on" and "gun off" can be associated with each point. The engineer presses the download button, and a file is created by Robcad that the programmable multiaxis controller can understand. This technology allows engineers to make changes quickly and precisely while remaining in control of the painting process. The basecoat booth is similar to the primer booth, with nine bells in the automatic spray zone. White and black colors get a single-pass basecoat; metallics need a second pass. The two-component clearcoat is applied with bells, also from Behr. Although the Mercedes facility sports many innovative design features, its management points to its personnel as the driving force in the success of the plant. "This has been a gigantic teamwork effort," Bugg says. "I’ve been involved with this project for four years. Mercedes offered us a unique opportunity, not only to help design the plant, but also to help develop the new M-Class vehicle. We had direct input to what was happening with the vehicle over in Germany as it was being developed. That input is not normally afforded to a production manager." That emphasis on the importance of people extends through every operation at the plant, from managers to line operators. "The enthusiasm of people on the line keeps the plant running at really high level. It’s also one of the cleanest shops I’ve ever worked in," Pizzato says. Bugg agrees. "You can have all the best equipment in the world, and if the people aren’t motivated, you won’t have the same high-quality product," he says. credits PPG IPP ABB Dürr BASF MBUSI |
written in January 2006 and updated from time to time
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Veni, vidi, M. |