Polymer options abound
Today’s automotive designers are looking for system optimization, greater design freedom, process improvement, and the ability to adapt to regulatory changes. Polymers are providing answers to these challenges, and the palette of choices keeps growing.
Long-fiber and carbon-fiber composites are making their way into structural and semi-structural applications such as exterior panels, stiffeners, mechanical components, seat components, accessories, underhood components, brackets, and fixtures.
Thermally and electrically conductive plastics now sport 10 to 100 times more conductivity than conventional plastics, a level equivalent to stainless steel. They’re making their way into heat sinks, EMI/RFI shields, and a range of components for hybrid electric and electric vehicles, such as connectors, power electronics, and infotainment modules.
Replacing painted metal with metallic-filled polymers for engine covers offers greater design freedom while reducing VOC emissions and production cost.
Proof in production
One recent success story underscores the fact that not all materials replacement in vehicles involves metal to plastic conversion. Designers at DENSO, a leading technology, systems, and components supplier to major automakers worldwide, were seeking an alternative to a TPV seal used in the HVAC unit of a new car model, looking to enhance the overall performance of the system.
DENSO collaborated with PolyOne, a leading materials solutions provider, on a thermoplastic elastomer (TPE) solution that met their in-service performance goals while reducing the total system cost by eliminating the need to pre-dry the material. The TPE alternative also provided more than a 5 percent improvement in processing efficiencies thanks to shortened cycle time and scrap reductions.
Current metal replacement projects prove that it isn’t always just steel that’s being replaced. Thermally conductive polymers are now replacing aluminum, which is a traditional, lightweight alternative to steel for automotive designs.
Aluminum heat sinks are used in automotive high-brightness LED headlamps to reduce overheating and hot spots that can shorten the lifespan of the entire unit and reduce its lighting performance. While LEDs consume less energy, managing the heat generated by LED electronics is critical to maintaining useful life and energy efficiency.
Replacing aluminum heat sinks with thermally conductive polymers that are 40 percent less dense than aluminum enables efficient heat dissipation like aluminum while also reducing weight.
Headlamp suppliers are also finding that a move from aluminum to plastic gives them the ability to create custom shapes to meet the need for product differentiation among automakers, for which headlamps have become a signature. In addition, the removal of secondary operations such as drilling and painting are a welcome benefit.
Kendall, we'd be very interested in 3D printing of this material, in addition to automotive uses. That sounds like my department. Can you please contact me about this?
Thanks,
Ann Thryft, Senior Technical Editor, Materials & Assembly, ann.thryft@ubm.com
Kendall. Thanks for getting back to me. I was thinking of something similar to the way fiberglass panels are made with a metal mesh replacing the glass mesh. Don't know if that is even practical or has been tried. It just seemed like an interesting idea.
Scott, not sure what sort of construct you mean specifically by a 'hybrid.' Some of our systems are filled with various substances. Metals sometimes play a role. But the metal itself doens't play a role for strength. Obviously the trade-off when systems are more highly filled is for strength properties (flex mod, impact). I think maintaining this balance is more critical for automotive applications than say electronics. We are also looking at composite-based constructs for these types of properties. Best, Kendall -
Greg, LED lighting is one area we've looked at extensively and yes, I think that conductive polymers can play a big role in heat management of the new LED systems.
I agree Kendall. The improved thermal conductivity of many polymers is now opening design doors that were previously closed for us. In addition to metal heat sinks that may have been overspecified in the past, new LED technologies burn cooler and brighter, so the opportunity to replace a metal heatsink with a thermally conductive plastic heatsink may now be available.
I found myself wondering if there were some polymer/metal hybrid materials out there for use in automotive applications? Is that a practical tradeoff for weight, strength, conductivity, etc.? Any thoughts?
Not that conductive, but sounds like a great material that can both house and supply data for low voltage sensors. I wonder if this is being explored. Also, a great way to send power or a signal through a enclosed container. That is if both conductive and non-conductive plastics can be molded together. Sound like this will revolutionize the automotive sector sometime soon.
Designing trade-offs are always more complex than getting exact matches of properties. The thermally conductive compounds referenced in the article have thermal conductivities up to about 20 W/mK. While that isn't quite equivalent to aluminum at 100W/mK, it's over 3 orders of magnitude improvement over base plastics which sit at around 0.1 W/mK.
That does make these formulations viable options for heat management. We've done several design cases in areas such as automotive lighting and have shown that those sorts of conductivities are more than enough to replace metal heat sinks which in many cases are *overspecified* for thermal conductivity.
As to 3D printing. We have 3D printing capability and development programs to be able to print some of our key functional formulations. Happy to discuss further if you like.
When demand is there, surplus is there. You can still buy car parts, new, from popular models from the 80s. They made so many of them, they are still cheap.
The low-hanging fruit of plastic-to-metal conversion is no longer there for the taking, but that doesn't mean there are no opportunities. This article does a good job of explaining how to go about finding these opportunities: design engineers should sit down with suppliers or other experts, with a focus on part function. You are probably not going to make the same exact part out of plastic that you made out of metal -- at least, not if you want the part to work! But, with a little creativity, you might be able to get the same function. It takes design ingenuity, along with a knowledge of what's out there in terms of materials. This is where suppliers and outside experts can help.
An analysis of what’s needed to implement Design for Disassembly and Design for Recycling results in eight strategies engineers can use to design an intentional end-of-life stage into their products.
Government regulations, coupled with growing consumer sensitivity about data and identity theft, require that data storage organizations demonstrate proper protection and due diligence in protecting sensitive information stored inside datacenter enclosures.
When a crane doesn't have a monitoring system, crane owners schedule service every six months and simply scrap the parts they replace, even if a part has had little use and doesn't need replacing. This can cost thousands.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
9 
