While most automotive headlines focus on autonomous vehicles or electric drive, the “big story” on the industry might really be its focus on sustainability and materials conservation. Over the last two decades the auto industry has invested billions in materials science, and the results are impressive.
Most people think of carbon fiber when they hear the term “composite material,” and certainly the use of that material in weight-saving structural component applications is one of the significant trends in auto design, but the better way to think about the use of fiber technology might be through the use of two acronyms – NFRP and CFRP.
Natural fiber reinforced plastics (NFRP) have been used for almost two decades in vehicle manufacturing and have expanded from non-structural interior components to a full array of composite applications. The results are lighter parts with strengths equal to steel or full ABS plastics.
Some NFRP examples: Automakers are increasing the use of flaxseed for instrument panels and other interior parts. OEMs are using wheat straw fibers in center consoles and door bins to make them both strong and biodegradable. Soy foam is now displacing 10 percent or more of standard oil-based foams used in head rests and seat cushions. Jute and hemp fibers or mats are woven into plastic and phenolic panels. Even coconuts are being applied for both their fibers and oils in the formation of interior parts.
Carbon fiber reinforced plastic (CFRP) is as strong as the steel it is replacing but roughly 50 percent lighter. BMW is a leading user of this steel substitute, and its new 7 Series sedan is a great example of commitment to CFRP innovation.
BMW has reported that its new 7 Series is 286.6 pounds lighter than the previous generation vehicle it replaces even though the car is equipped with more safety gear, which adds weight. BMW attributes the weight savings to what it calls its “carbon core.”
Used in conjunction with high-strength steel and aluminum components, 15 CFRP components are used in the roof structure, B and C pillars, doorsills, transmission tunnel and the rear package shelf. BMW has invested heavily to perfect the CFRP B Pillar “hybrid press” process, which combines traditional steel stamping and the principles of injection molding. Resin-impregnated carbon fiber sheets are added to steel blanks, which are pressed and held in a slow moving three-dimensional wet-press die process.
The result is a part of exceptional dimensional accuracy and performance strength. To continue its focus on weight savings, BMW uses aluminum for the car’s hood, doors, deck lid and suspension components.
The use of high-strength fiber reinforced composites is forecast to grow 17 percent annually, and BMW is investing a lot to stay with that trend. An example of its focus is the joint venture with SGL Automotive Carbon Fibers based in Moses Lake, Washington, and the recent expansion of that facility’s production capacity. Why Moses Lake? Carbon fiber production is energy intensive, and Moses Lake sits on a hydroelectric dam.
Plastic recycling has been a mainstay of the auto industry for many years with a high percentage of “non-surface” structural components being made of recycled materials, and new processes are continuously feeding the industry with new products. A great example is Repreve.
If you ever wondered where your recycled plastic water bottles go, you might be sitting on them if you drive a Ford vehicle. The Repreve process shreds bottles into polyester flakes, then rebuilds the material into forms that work for Ford Fusion and Ford Focus Electric seats. The Focus Electric contains 22 water bottles of Repreve content while the Fusion requires 42. Repreve estimates that the first production run of the new vehicles will require about 2 million recycled bottles. Visit www.repreve.com to see the wide range of products using Repreve material.
Paint and Paint Systems
The paint line in an auto assembly plant is the most energy intensive portion of the manufacturing process and one of the most environmentally challenging. Several different approaches have been taken to reduce costs and greenhouse gases (GHG).
One of the first moves was to use primer-less coating systems, which allowed manufacturers to eliminate baking periods by electro-coating vehicles and moving straight to a color basecoat saving over 30 minutes per vehicle, using less energy and producing less GHGs.
Some companies then moved to ECODry technology to use limestone powder to collect overspray, thereby saving tens of thousands of gallons of water per day at a typical plant.
Today, many plants are using water-based processes that include primer-less paint applied in three wet coatings, which provides the required layer performance without flashing or baking between coats. Clear coating is still the preferred method to obtain excellent surface quality and scratch resistance on passenger vehicles, but products like Xalta’s Monocoat (currently being used for utility vehicles) are showing that long-term durability and surface quality can be generated without a clearcoat. Further development of that formulation may be the next step in reducing the costs and environmental impact of automotive paint systems.
Silicon Valley and web-based companies get all the business press these days, but the automotive industry is one the best examples of sustainability and process innovation in the world… and the innovations continue.
The reference to any specific commercial products, processes or services by trade name, trademark, manufacturer or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by ICA or Schwartz Advisors. The views and opinions of the author do not necessarily state or reflect those of ICA staff.