Automotive lightweighting is a big deal these days in the world of plastics, with US Corporate Average Fuel Efficiency (CAFE) requirements that will force automakers to jack up mileage to 35.5 mpg by 2016, and to 54.5 mpg by 2025. Major plastics manufacturers are responding with new formulations to achieve these drastic reductions in fuel consumption by losing as much weight as possible in every part of the vehicle while maintaining strength, toughness, impact resistance, chemical resistance, and other properties in replacement materials. Many of these plastics were on display recently at NPE2012 in Orlando, Fla.
Click on the image below to see these some of these solutions on display.
The smart forvision electric concept car co-developed by BASF and smart has several features that help it lose weight. One of the main ones, which BASF showed at NPE, is the polymer wheel rim made of its Ultramid Structure, with long reinforcing glass fibers, which saves up to 30 percent of the weight of a metal wheel rim. BASF representatives said this is the first polymer wheel rim that can be mass-produced. (Source: BASF)
@Nadine- I have a keen interest in motorcycle and bike helmets as a rider of both and as an engineer. As others mentioned the best-performing motorcycle helmets use fiberglass, or lately Kevlar or carbon fiber for very high-end products. Polycarbonate is used for "budget" motorcycle helmets. They are heavier and there have been a few cases of splitting along mold lines in an impact.
You're correct that some of the new materials and processes in this article may shift the advantage back to plastics in helmets. (BTW, bicycle helmets are almost always a thin plastic shell with a thick polystyrene liner).
An aside- one big area for improvement is a truly "quiet" motorcycle helmet. The best helmets available still deliver 100+ db of wind noise at highway speeds, making earplugs a necessity. Most riders don't use earplugs...probably a source of regret in 10 years. (Mild tinnitus is my personal toll for not using them earlier)
Thanks for that input, Dave. As the (correct) caption states, "The new formulation was developed to help overcome performance issues of fiberglass and metal, such as cracking or fading from exposure to high temperatures and ultraviolet light. SABIC's Lexan SLX resin is co-extruded over its Cycoloy resin and vacuum formed..." When talking to SABIC, they made it clear that they had worked closely with Apache to develop this material and overcome previous difficulties. The same goes for the white Volvo truck cab roof fairing made entirely from SABIC's Cycoloy polycarbonate/ABS resin, which they worked closely on with Volvo.
@Ann: Well, I'm not sure which metals SABIC is thinking of which crack or fade from exposure to high temperatures or ultraviolet light! (Certainly not if "high temperatures" are defined as temperatures which would be high for plastics).
As far as fiberglass is concerned, I don't doubt that PC and PC/ABS have better weatherability than a fiberglass-epoxy composite. But I think they are trading one problem for a potentially worse one. Fiberglass has excellent chemical resistance. With PC and PC/ABS, you now have to worry about splashing gas or oil on the hood of your tractor. (Not to mention pesticides and other chemicals).
An injection molded hood will be cheaper and lighter than a compression molded composite hood or a formed metal hood. But I'm very skeptical of SABIC's claim that the performance will be better.
PC and PC/ABS might look attractive compared to other injection molding resins because of their impact strength, but their chemical resistance is not very good. Better choices might be BASF's Terblend, or Ineos' Triax, both of which are nylon-ABS blends. (They used to be competing products, but since BASF and Ineos combined their styrenics divisions into one company called Styrolution, they're now both under the same roof).
naperlou, thanks for that input: plastic in firearms is a new one to me. That must be a very demanding application: heat, force/impact, etc. In automotive lightweighting, much of the materials design effort is to combine lighter weight composites and plastics with additional safety features.
Plastic has been user in firearms for decades - the Remington Nylon 66 was introduced in 1959 - but only recently in components other than stocks. Perhaps the best know weapon with a plastic stock is the M-16 of the Vietnam era. Now plastic frames, magazines, triggers and guards, and other components are routinely found in all types of firearms.
More on topic with the automotive direction of the blog, does anyone remember the Polymotor® from the mid to late 90's? As I recall most of the components, inluding the block and head, were made of plastic with metal inserts in high wear/high stress/high temperature areas. I believe the entire engine - it was a 2.0 liter 4 cylinder racing engine - weighed ~ 200 pounds.
I can understand how plastics will save weight in cars. However, I am concerned about a problem I am already running into with plastic parts in cars. I have an 2009 Toyota Matrix, and a 2010 Mazda5. Both of them use lots of plastic. In trim parts inside the car, and outside items like bumper covers that actually go up into the body. These parts use molded in plastic clips to attach the parts together and to the body. I have had a number of the clips break or come apart from normal use. My choices have been to either spend a fair amount of money to buy new parts or do what I can to come up with ways of using the parts on hand with my own solutions. So far I have chosen to fix them myself. While it works, it is not always the nincest looking result.
My fear is that with even more plastic in cars this problem will get worse. Will the car designers take this into account and come up with stronger and more reliable connections? Plastic headlight lenses save weight, but they loose clarity over time and must be polished in order to have a safe level of lighting.
Oak Ridge National Laboratory has developed a surface preparation method to improve joining carbon composites with aluminum, with potentially far-reaching ramifications for high-volume industrial applications.
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