Natural Materials Are the New Job One at FordNatural Materials Are the New Job One at Ford

It's back to the future for plastics researchers at FordMotor Co.

Henry Ford famously unveiled a "Soybean Car"in 1941 at an annual community festival in Dearborn, MI. Fourteen plasticpanels strengthened with soy fiber reduced the weight of the car by half. Itwas never built because focus quickly shifted to military requirements.

Today a six-member engineering team at Ford is looking fornew applications for soybeans and other sustainable materials in anindustry-leading effort to replace hydrocarbon-based materials.

"Wherever petroleum-based materials exist - in plastic,rubber, foam, film or fabric - we are looking to minimize its proportion andreplace it with a sustainable material," says Dr. Cynthia Flanigan, technicalexpert in Ford Plastics Research.

The group, formed in 2000, has had tremendous success todate. Soy-based foam seat cushions and backs will be used in more than onemillion Ford, Lincoln and Mercury vehicles by the end of this year, leading toa total reduction in carbon dioxide emissions of more than 5 million lb.

"We started looking at soy-based polyurethane foams in 2001,"says Dr. Deborah Mielewski, the leader of the group told Design News in an interview. The first foam produced in the lab hada rancid odor, poor compression set and poor mechanical properties.

"This is where the chemical companies and most of the supplybase pretty much ended looking at hydroxylated soybean oil as a component inautomotive foams," says Mielewski.  "Mygroup had a formulation chemist named Christine Perry who said, ‘I think I cando it.' She went away and made hundreds of different formulations, and thewhole point was to balance two reactions: the crosslinking reaction and the blow reaction that makes the cells,and over a two-year period she did it."

The first production model to use the new foam was theMustang in 2007. It's now used in seven vehicles.

"It definitely has further potential," says Mielewski.  "We think we can do headrests. The headlinerin the Ford Escape will use soy foam starting this month. We feel it could beused for door arm rests. We can use it anywhere there is urethane foam."

Soy oil is used to replace hydrocarbon-derived oils to makepolyols, one of the reactive components that produce polyurethanes.

Soy FlourReinforcements

"You also get flour or meal from the soybean," saysMielewski. "Now we're studying if we can use that for reinforcement forplastics." That takes the company right back to Henry Ford's demonstration carin 1941. In fact, meal constitutes 82 percent of the soybean. 

Some of the specific projects at the research departmentinclude the following uses for soy fillers:

·      Incorporation of up to 24 percent soy filler inrigid polyurethane foams.

·      Up to 30 percent soy flour can be used innatural rubber. Results to date are positive.

·      Use of soy fillers in EPDM (synthetic) rubber.Ford is collaborating with suppliers on development of actual parts. Results todate are promising.

·      Use of soy as a filler in polypropylene,thermoplastic olefins and thermoplastic elastomers. The soy flour couldpotentially replace mineral fillers or hydrocarbon materials.

·      Use of soy as a component in automotive paints.

Some of the work on soybean development was funded by athree-year $230,000 grant from the United Soybean Board.

One of the interesting aspects of Ford's research is itsemphasis on local crops. Some automotive OEM's are boosting use of polyamide 11made from castor oil. Mielewski says Ford is not testing the castor oilpolymers because its focus has been on local crops.

Another potential local feedstock for Ford vehicles is the Indiangrass that grows wild near roads in the Midwest.

"The big motivation in working on natural fiber is a 30 percentweight reduction compared to glass fiber," says Mielewski. "Also, glass fibertakes a lot of energy to produce, and you also get the carbon dioxide reductionbecause you're sequestering carbon dioxide in the plant when you grow it."

Other natural fibers Ford is studying include hemp, coconuthair (coir) and wheat straw.

"You have probably 10 to 15 different types of plastics oncars and 10 to15 different fibers you might like to use," says Mielewski. "Soit's a huge developmental process to find a plastics fiber combination thatmeets the requirements."

The issue is moisture absorption. "You mold the part andit's lightweight, but over time it picks up moisture," she says.

Natural fiber has been used for years in compression moldedseat backs. The new research is looking at injection molding, which takes placeat higher temperatures and pressures.

Bioplastics' Potential

Another area of interest, possibly farther out, is use ofbioplastics. "The big thing here is their compostability," says Mielewski. Thatis, after the parts finish their useful life, they are sent to a landfill wherethey decompose. Current plastics used on cars are theoretically recyclable, butin fact are mostly sent to anaerobic landfills, where they stay for a very longtime.

The big technical hurdle is timing the decomposition. "We'relooking for switches, such as a microbe that would exist in a landfill butwould never exist in the vehicle," says Mielewski. "With a switch, the materialwon't decompose until it's exposed to humidity, heat, and a microbe."

There's nothing in production yet, but closer may be use ofcompostable bioplastics for packaging, such as shrink wrap, used by Ford.

Mielewski has three degrees in chemical engineering from theUniversity of Michigan. She'll be the keynote speakerat the SPE AutomotiveComposites Conference Sept. 15-16 in Troy, MI.

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