Stemergy: Renewable Fibre Technology

Automakers' Natural Appeal

26 September 2008

Imagine you're driving by a lush, green farm. You see it as a source of food. Detroit automakers, however, see raw materials for their cars on the drawing board.

Why do automakers look at corn, soy and other farm products differently from the rest of us? Well, a car requires fuel and the heavier the car, the more fuel it needs--thus reducing efficiency. Natural materials are lighter and reduce the overall weight of the car, thereby making the car more fuel efficient.

Among the materials automakers are trying to integrate into vehicle construction are the natural fibers of prairie grass, wheat straw and coconut. These can be used to replace the heavy glass used for reinforcing certain components such as underbody and impact shields. Corn, sugarcane and soybean protein and natural oils found in canola, sunflower and rapeseed could displace petroleum as a key material needed to make seats, head and arm rests. All of these natural materials are readily available in North America.

So when will you be able to buy an environmentally friendly dream car? No one knows for sure, primarily because of the big roadblock facing automakers: costs.

"Many of these technologies are already on our existing vehicles," says Matthew Zaluzec, manager of the materials and nanotechnology department at Ford Motor Company (nyse: F - news - people ). "But do we have the right combination of technology to build lightweight parts, with the right cost structure for vehicles and something consumers want to purchase? Not in totality."

High a hurdle as cost may be, the automakers have no choice but to try and overcome it. Not only is Detroit facing increased pressure from consumers to build more fuel-efficient, environmentally friendly cars, the federal government in late 2007 mandated an increase in fuel economies by 2020 to a minimum average of 35 mpg.

Auto experts say machinery and infrastructure is needed to fully integrate natural and lighter materials. To make the fuel-efficiency goal a reality, the three money-losing auto giants--Ford, General Motors (nyse: GM - news - people ) and Chrysler--have asked Congress for a $25 billion low-interest federal loan. Much of that money, says Zaluzec, will be designated to retool plants and for the advanced-materials research needed to produce lighter and more fuel-efficient cars in order to meet the regulations.

Dropping Weight On The Inside

Roughly 33% of the weight of a 2,700-pound vehicle--about the average of a small sedan like the Ford Focus or Honda Civic--is attributed to interior components such as seats, doors, headliners (the ceiling) and components needed to operate the vehicle.

"We want to take out 30% of that weight by using lighter-weight materials," says Byron Foster, group vice president, global product centers, Johnson Controls (nyse: JCI - news - people ), a manufacturer of interior seats and systems.

Johnson has developed an "Ecobond" headliner made from soy-based adhesives and urethane core foam, plus natural fibers like hemp, flax and kenaf, which replace the fiberglass traditionally used in headliner production.

"New exotic materials cost more than the traditional resources we have used for years," says Foster. "Clearly a factor is the supply of natural fibers, which are not widely available. But as demand grows, the price of these materials will come down."

Though prices are currently high, the advantage is that most natural fibers are available throughout the U.S. Indiangrass, also know as North American prairie grass, is the official state grass of both Oklahoma and South Carolina. The coir fibers from coconuts, found between the husk and outer shell, are abundant in tropical places like Hawaii. And corn and wheat are major American crops. The USDA says the U.S. will produce more than 13 million bushels of corn and 2.4 billion bushels of wheat this year.

Fine an idea as using natural materials might be, they have a disadvantage in addition to their cost: Natural fibers are moisture-absorbing. If the materials absorb too much moisture, they emit an earthy odor--quite a contrast to that new-car smell.

Granted, this isn't a potential hazard with the time-tested petroleum-based products used in cars today, but with foreign-oil dependency a hot issue, automakers are looking to other natural oils. The cure-all castor oil, found in some home medicine cabinets, is in research labs alongside soy bean and other natural oils, says Foster. And when properly used, one day they could be suitable substitutes for petroleum-based materials such as plastic, rubber, foam or fabric, says Ellen Lee, a Ford technical expert on plastics research, natural fiber composites and compostable polymer resins. The natural oils won't lighten a vehicle's weight but they might go a long way toward conserving petroleum.


written by: Jacqueline Mitchell

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Stemergy bio-fiber is focused on producing and supplying renewable bio-fibres - derived from annual stem fiber plants such as flax and hemp - to the expanding global bio-fiber marketplace.