When developing the interior for the new 2013 Fusion, Ford engineers had a challenge: how to create a high-gloss window-switch surround component that was pleasing to the eye, yet was tough enough to withstand the rigors of repetitive bumps and scratches from the typical consumer. This new part had to gleam with the high-gloss, piano-black hue that seems to be the rage these days, but without using the clear-coat paint that typically has been employed to make interior parts shine and give it tough-as-nails durability.
Enter BASF Corp. (Florham Park, NJ, and Ludwigshafen, Germany), which teamed up with Ford and several suppliers to devise a formula to make a resin that not only would shine like a Steinway, but would still be tough enough to last over the long haul. “As part of designing finish panels for the interiors of our vehicles, we go through a real cross-functional team effort—the design studio, the program team, engineering, and the supply base in terms of manufacturing,” said Robert Bedard, body interior core engineer, IP & Console Core Engineering, Ford Motor Co. (Dearborn, MI). “We are passionate about making our vehicle interiors look absolutely fantastic, in terms of the way the parts appear—the styling, the theme, the color, the materials, the tactile feel, the sounds.”
Everything in automotive interiors today is leaps and bounds beyond what it was just 10 years ago, Bedard noted. “One of the things that’s in style right now is a high-gloss black, which is a shiny, real lustrous-looking black color,” he said. At the North American International Auto Show (NAIAS) in Detroit earlier this year, Bedard said most OEMs’ portfolios of cars and trucks showcased that style.
By skipping the clear-coating paint process, Ford also stood to reap huge cost savings on the window component while substantially reducing the environmental impact of producing the part. Without the clear-coat painting on the window trim, Ford estimates it saved 50% of the cost on the part, and it eliminates all of the volatile organic compounds (VOC) that would be released if the builder instead used the clear-coat paint process. By cutting just one step in the manufacturing process, Ford also didn’t have to ship the parts from its molder in Vicksburg, MI, to its painter in Grand Rapids, saving roughly 2700 gallons (10,220 L) of diesel fuel annually, and cutting some 59,400 lb (26,944 kg) of CO2 from Fusion production each year.
“One of the things we’ve been trying to engineer is a way to get the exact same appearance that you would get with a painted surface, but doing it only with the manufacturing process itself, thereby eliminating the need for paint,” Bedard said. “That’s the mantra that was really driving the adhering team: ‘How do we give the studio what they want, and also give the customer something that will hold up to the wear and tear? How do we find that balance?’”
Partnering with BASF ultimately allowed Ford to achieve a balance of the color and the gloss desired, Bedard said. “It’s what we call the depth of image—when you look into parts that are high gloss, they tend to have kind of a mirror effect,” he explained. “You can kind of look into the part, if you will, almost like a lens.”
Finding the Right Recipe
To find the right mix, Ford teamed up with BASF’s engineers plus several of its own suppliers including NADA Innovation Co. (Allen Park, MI, and Korea), developer of a key technology called E-MOLD for plastic injection molding; its molding supplier Summit Polymers (Vicksburg, MI); Synventive (Peabody, MA), developer of the hot-runner technology used in the molding process; and Michael Tool & Mold (Oldcastle, ON, Canada).
The team started with a standard BASF polymer grade, Ultramid A3L, manufactured at BASF’s compounding facility in Sparta, TN, said Mark D. Minnichelli, director, Technology and Development, BASF Performance Materials/Engineering Plastics (Budd Lake, NJ). “It’s built on a polyamide 66 material, that’s the base resin,” Minnichelli noted. “Polyamide is the proper chemical name for the product commonly called nylon.”
BASF’s business is compounding various recipes to design thermoplastic materials to meet customers’ needs, Minnichelli said. “We took one of our standard base materials and we came up with a new recipe that allowed us to compound in other resins and additives in order to achieve the desired performance. It’s an impressive part. It’s got that deep, rich-black high gloss. The challenge that we were presented with is have that color and also have good scratch resistance. This happens to be the most aesthetically demanding internal automotive application that we’ve done.”
Painting typically is the way manufacturers will get the look and the protection required for these applications, he added. “The major accomplishment of our team was to develop a material that had a rich, deep-black, high-gloss appearance as molded, with a highly durable scratch-resistant surface, and UV-stable color performance,” Minnichelli said. “These attributes are challenging to achieve simultaneously. I can tell you that unique process technology was important to achieving the product requirements on this project.”
With BASF product developers working with Ford and the other team members, the developers came up with formulas that later had to be further refined to meet Ford’s durability requirements. The team had to develop a new test procedure that allowed rating relative improvement of what’s called mar, Bedard added, after earlier iterations were not up to par.
“Mar is like a microscratch. It’s not like a deep gouge,” Bedard said. “If you can imagine just touching a surface over time that’s high gloss, it’ll start to get these tiny little microscratches in the surface.”The development team was able to show relative improvement with new iterations until Ford eventually had the recipe that gave the balance between color, gloss, depth of image, and durability, Bedard said, among other requirements for impact, and other types of strength and characteristics for assembly.
Molding Process TechnologyIn the plastic injection mold process Ford used, the resin is pelletized so the material is extruded into “long, black spaghetti,” Bedard observed. This process includes using a tool in the injection-molding press that is outfitted with a superheating and supercooling technology that allows the resin to remain in a laminar state, where it will mix homogeneously throughout the tool.
“When the resin is at a high temperature, it likes to mix with itself around various surfaces,” Bedard said. Allowing the resin to achieve this type of mixing avoids or mitigates surface imperfections, he added, that manufacturers can get when using conventional injection molding processes.
Ford’s Tier One supplier Summit Polymers worked with the automaker and BASF to mix the resin, and NADA Innovation, the US office of NADA Innovation Co. Ltd. in Korea, supplied E-MOLD, the technology enabling the molding process to have the rapid heating and cooling capability that allows tools to be heated and cooled with precision, Bedard noted. Ford’s tooling supplier, Michael Tool & Mold, added the actual tool that gets put into the press.
“The NADA technology is put into the tool, and there’s also part of the technology that’s connected to the press,” Bedard added. “The tool shop, Michael Tool & Mold, had to pull all those elements and make sure everything worked, along with our hot-runner supplier, Synventive. That’s all integral to the tool, but it was really all of us working together. It wasn’t one company knowing all the answers.”
Hot runners or manifolds are a system within an injection molding tool that helps keep the resin at a constant temperature throughout as the resin’s coming into the tool, which is different than the NADA E-MOLD technology, he noted. “E-MOLD superheats the cavity, or supercools the cavity, which is what makes the beautiful Class A appearance surface,” Bedard said. “Keeping the resin at a constant temperature, and keeping it hot, are super-critical to being successful with these technologies.”
The E-MOLD technology has worked so well for NADA Innovation that the Korean company has opened a sales and engineering office in Allen Park, MI, to work with Ford and other manufacturers, according to Kevin Foley of NADA Innovation USA. Various hot and cold technologies for moldmaking have been used in the TV and electronics industries for some time in Korea, Foley said. “Ford continues to improve on this already proven technology through their own work with their internal advanced technology team. Several new programs are being considered due to the past program results and cost savings. We appreciate the partnership with Ford to continue to look for ways to advance the technology even further into new finishes and benefits in Class A parts.”
More Lightweighting with Thermoplastics
For automakers to meet the 54.5-mpg (128 L/km) corporate average fuel economy (CAFE) requirements in 2025, more lightweight automotive components using thermoplastics may help manufacturers meet that mileage goal.
“Engineering thermoplastics have been used in cars now for several decades,” BASF’s Minnichelli noted. “One of the things I noticed when sitting in the cars at the Detroit show was how good the interiors looked. They’re actually beautiful parts to look at. This is an opportunity for OEMs in the auto industry to differentiate themselves.”
The need to differentiate products and make them stand out from the crowd is a trend driving automotive, he added.
“Auto products need to be lightweight to be green, if they’re going to meet the new 54.5-mpg standard by 2025,” Minnichelli said. “It provides us a challenge, and some huge opportunities to look more intensely and re-attack some of the metal-replacement areas that we thought might be too difficult before. We need to use new processes, like continuous fibers, which are a type of thermoplastic composite. We’re working on some new things under the hood and in the cockpit, and have begun to commercialize some of those.”
New auto applications for thermoplastics include oil pans made of polyamides, said Minnichelli, and BASF engineers are currently investigating wider use of thermoplastics for chassis components, such as engine mounts and transmission braces. ME
This article is a digital exclusive feature for the March 2013 edition of Manufacturing Engineering magazine
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