Automotive: Green gets in gear
With environmentally friendly green products becoming today's norm, it's no surprise to see them being incorporated -- via renewably-sourced biopolymers -- into one of the most important aspects of daily life: our cars.And yet a lot of people...
With environmentally friendly green products becoming today’s norm, it’s no surprise to see them being incorporated — via renewably-sourced biopolymers — into one of the most important aspects of daily life: our cars.
And yet a lot of people probably are surprised. “For years, many manufacturers regarded biopolymers as fine for disposable packaging applications, but not suitable for use in auto parts, and definitely not geared for under-the-hood applications” said Craig Crawford, president and CEO of the Ontario BioAuto Council, a provincially funded agency that provides support for biomaterials ventures and commercialization. “This view is changing, though, and the amount of biopolymers in auto parts is definitely growing.”
It’s hard to argue this last point. More and more automakers — including heavy hitters like Ford Motor Company, Toyota and Mazda Motor Corp. — are turning to biopolymers as a substitute for traditional petroleum-based plastics. It’s easy to see why. Today’s consumers want to feel that they’re being good to Mother Nature, and car makers are anxious to tap into that by creating an image of sustainability, while also pursuing their own end of replacing metal wherever possible. Biopolymers are an obvious answer, marrying the chic of natural ingredients with the tried- and-true weight savings of polymer-based plastics. And with plastics currently making up approximately 10 per cent of the average vehicle, there’s definitely room for the use of bioplastics to grow. Add to this the fact that automobile companies are expected to begin imposing certain obligations for the supply chain to provide products that are environmentally friendly, and the door for biopolymers seems wide open indeed.
But it’s not quite that simple. Despite being among the most recycled consumer products in the world, cars aren’t comparable to single-use grocery bags — whatever goes into your car has to meet high quality standards of strength and durability. In short, car parts have to last. For many, the question is still unanswered: can biopolymers measure up?
THE INSIDE STORY
For interior parts at least, the answer is a resounding yes. While increased usage of bio-based materials in plastics is still in the advanced research stage, biopolymers are already being used in some recent interior applications such as car seat cushions, carpeting and more. “Natural fibre-reinforced plastics are becoming the materials of choice for car interiors, from both the production and the economic points of view,” said Craig Crawford. “Recent technical developments for biopolymers for interior parts allow them to meet the quality standards of high degree of strength, low degree of damage from sunlight, good resistance to abrasion, high durability and high resistance to fire.”
A leader in green interiors is Ford. Late last year, Ford said it became the first automaker to use wheat straw as plastic filler, in the third-row plastic bins on the 2010 Ford Flex model. Designed to replace the glass fibres commonly used to reinforce plastic parts, the material was developed by plastics compounder A. Schulman and Ontario’s University of Waterloo as part of the Ontario BioCar Initiative, a partnership between Canadian universities and companies interested in developing sustainable car materials. The bins might be a small component, but Ford anticipates saving about 20,000 lbs. per year of petroleum nonetheless, and also cutting CO2 emissions by 30,000 lbs. per year.
Glass fibre applications, in fact, are widely sighted for replacement by an array of lighter biopolymers. “Ford is examining the possibility of replacing glass fibres with natural fibre reinforcements made from cellulose, soy protein, hemp fibre, flax fibre and other bio-based materials,” said Debbie Mielewski, technical leader, Ford Plastics Research. “So far, lab test results have been promising, with the natural fibre-reinforced plastics showing up to a 30 per cent weight reduction, depending on the part.”
The company is also increasing the use of renewable and recyclable materials such as the soy and bio-based seat cushions and seatbacks on the 2010 Ford Taurus, the eleventh Ford vehicle to incorporate these. No wonder Ford claims to have more vehicle models with seats that use soy and other bio-based foams than any other automaker. Ford Mustang, F-150, Focus, Flex, Escape, Expedition and Econoline as well as Mercury Mariner, Lincoln MKS and Navigator also use the sustainable material.
Taking the idea of a greener automotive composite a step further, Ford is also working with the biodegradable plastic called polylactic acid (PLA), which is derived completely from the sugars in corn, sugarbeets, sugarcane, switch grass and other plants. Potential automotive applications for PLA are wide ranging, Mielewski said, from textile applications for vehicle carpeting, floor mats and upholstery to interior trim pieces that are injection molded.
All told, Ford saved an estimated US$4.5 million by using recycled materials in 2009, and diverted between 25 and 30 million lbs. of plastic from landfills in North America alone.
A big fish in the interior parts pond, Ford isn’t the only one testing the waters. In March 2009, Mazda began leasing its Premacy Hydrogen RE Hybrid vehicle, in which the car seat fabric contains a high-heat-resistant PLA-based plastic called BioFront made by Japanese chemical company Teijin.
GETTING UNDER THE HOOD
In some ways, under-the-hood parts are an automotive final frontier for biopolymers — an area where, only a few short years ago, virtually nobody thought they could go. This is about to change — and maybe sooner than you think. Biopolymers said to satisfy the high temperature requirements for under-the-hood parts are in use right now — and in at least one case, winning an award. (See sidebar on pg. 12.)
Arkema’s new Rilsan HT, for example, is described by the company as a plant-based polyamide that can replace metal in tubing for high-temperature auto applications. As much as 70 per cent of the material comes from renewable non-food crop vegetable feedstock. Also, the material is said to be significantly more flexible than previous polyphtalamide formulations, and to possess excellent thermoformability and fitting-insertion properties. “Because it can withstand temperatures of up to 150°C, Rilsan HT constitutes a viable alternative to the metal hoses usually used in car engines,” said Greg Poterala, automotive market manager, polyamides, with Arkema. “Peugeot and Volkswagen have already replaced the metal hoses found under the hoods of their cars with equivalent components made from Rilsan HT. Until now, this kind of application was unimaginable for a thermoplastic material.”
In April, Dutch chemical company Royal DSM N.V. introduced a high-heat-resistant castor oil-based polyamide engineering plastic for automotive applications called EcoPaXX. “As far as we know, EcoPaXX is the first high-heat-resistant engineering plastic which has more than 50 per cent bio-based origin, while achieving the same performance profile as its traditional counterpart,” said Nico Gerardu, member of the DSM managing board of directors and responsible for DSM’s performance materials cluster. “Automotive applications made with EcoPaXX are mostly in the engine compartment, and we expect to see the material made commercially available for vehicles in the first quarter of 2011.”
Alongside EcoPaXX, DSM also launched its Palapreg ECO composite resin, which contains 55 per cent renewable-based resources, for use in exterior auto panels. Several customers in the automotive industry are putting both Palapreg ECO and EcoPaXX through final approvals, DSM said.
Another exterior application currently in development has the Ontario BioAuto Council placed front and centre. “We’re working with Dow Chemical Company and BayerMaterialScience to develop a bio-based polyurethane (PU) load floor for SUV and van li
ft gates,” said Craig Crawford. “The design involves a honeycombed cardboard core with a bio-based PU top and bottom skin, reinforced with fiberglass fibres. We’re also exploring ways of replacing the fiberglass with natural fibres.”
CHALLENGES ON COST, PERFORMANCE
These examples notwithstanding, there’s one point on which virtually every biopolymer researcher agrees: for the materials to achieve meaningful penetration of the auto parts market, they have to be able to compete with traditional plastics in the two big areas of price and performance.
“At the moment, a lot of biopolymers cost more and withstand less than the traditional petroleum-based polymers,” Crawford said. But there are indications that pricing, at least, might not be a problem for much longer. “The cost associated with bio-based chemicals and plastics has been less volatile lately than petroleum-based products. And in the longer term, they’re expected to become cheaper as the technologies mature and production achieves economies of scale,” Crawford added.
In the short term, however, biopolymer pricing is hurt by the well-established nature of the petroleum-based polymer supply chain. “Petroleum-based polymers have been used for years in high volumes, so manufacturing and supply chain efficiencies are very high,” said Rick Bell, marketing manager for DuPont Performance Polymers. “It’s a difficult structure to compete against.”
Equally daunting are performance issues relating to durability and processing — challenges that are spurring wide-ranging collaborations among researchers. For example, Ford’s Debbie Mielewski and her biomaterials group have teamed with the Ontario BioCar Initiative. What are they targeting? One big roadblock, first, is moisture absorption: natural fibre-reinforced plastics are more likely to absorb moisture over time, causing functional and durability concerns. Other obstacles are odors — injection molding at high temperatures with a natural fibre-reinforced plastic can emit an undesirable smell — and decomposition: PLA is designed to decompose quickly, but Mielewski and her colleagues want to ensure it will last the lifetime of a vehicle before the decomposition process starts.
Ford isn’t the only automaker taking the proactive approach. Mazda developed its own high-strength, heat-resistant bioplastic in 2006 as part of a consortium that included two universities, seven manufacturers and two research institutes. Made of 88 per cent corn, the bioplastic is being used in both interior and exterior body panels. The company used a new nucleating agent for crystallization and a compatibilizer compound to raise the strength and heat resistance of the plastic.
Next up for Mazda? The creation of an automotive bioplastic from non-food-based biomass, such as plant waste, which the company hopes to have ready by 2013.
STEPS TOWARDS SUSTAINABILITY
For biopolymers to pose a true threat to traditional plastics, a lot of hard scientific work still lies ahead — and part of the challenge, according to Craig Crawford, involves nothing less than shifting the emphasis of current biopolymer development. “In the past, the priority in biopolymer research was, in a sense, short sighted: the goal was to improve biodegradability to make the materials more attractive to packagers,” he said. “Material suppliers hoping to make the transition into auto parts markets will have to concentrate on improving durability and price-competitiveness.”
While the jury is still out on when — and sometimes how — these nagging price and performance issues will be solved, we just might just look back on 2009 and 2010 as the point when biopolymers showed the first signs of becoming legitimate players in the auto parts world.
And if it’s taken a while — well, maybe that’s the way it should be. “We have to entertain the thought of bio-replacement in baby steps, looking at every aspect of a car that could be green,” said Ford’s Debbie Mielewski. “It’s the best way to get to where I hope to see the world of automotive plastics go: totally compostable, removing petroleum 100 per cent.”
A. Schulman (Akron, Ohio); www.aschulman.com; 330-666-3751
Arkema Canada Inc. (Burlington, Ont.); www.arkema.ca; 1-800-567-5726
DSM Engineering Plastics (Evansville, Ind.); www.dsm.com; 812-435-7500
E. I DuPont Company (Mississauga, Ont.); www.plastics.dupont.com; 905-821-5193
Ontario BioAuto Council (Guelph, Ont.); www.bioautocouncil.com; 519-827-1118
Ontario BioCar Initiative (Guelph, Ont.); www.bioproductsatguelph.ca; 519-824-4120, Ext. 56602