Turning to Mother Nature to Help Create Composites that are Durable and Lightweight

Ford researchers are taking a hard look at traditional, petrol-based plastics, turning to Mother Nature to help create composites that are durable, lightweight and better for the environment.

While petroleum and glass fibers are typical ingredients associated with today's automotive plastics, Ford's research team is developing all-new composite recipes that include more natural ingredients such as soy flour, hemp, cellulose, and the sugars in corn, sugarbeets and sugarcane.

Nature made
Plastics currently make up approximately 10 percent of a vehicle, ranging from sight-unseen parts such as impact shields and engine covers to components drivers see and interact with everyday, including doors and instrument panels. Some of these plastics have fillers such as heavy glass fibers for added strength. Ford is examining the possibility of replacing those glass fibers with natural fiber reinforcements made from cellulose, soy protein, hemp fiber, flax fiber and other bio-based materials.

So far, lab test results have been promising, with the natural fiber-reinforced plastics showing up to a 30 percent weight reduction depending on the part.

Taking the idea of a greener automotive composite a step further, Ford is also working with a biodegradable plastic called polylactic acid (PLA). Derived completely from the sugars in corn, sugarbeets, sugarcane, switch grass and other plants, a plastic part made from PLA can biodegrade after its life cycle in 90 to 120 days versus up to 1,000 years in a landfill for a traditional, petroleum-based plastic.

Potential automotive applications for PLA are wide ranging, from textile applications for vehicle carpeting, floor mats and upholstery to interior trim pieces that are injection molded. More immediate possibilities include using PLA for nondurable auto applications such as protective wrappings used during vehicle manufacturing and transit.

Composite challenges
The presence of more bio-based materials in automotive plastics does pose mechanical performance, durability and process challenges that Debbie Mielewski, technical leader of Plastics Research at Ford, and her four-person biomaterials group are hot to solve.

To speed up development, the Ford team is working with several organizations and universities, including the Ontario BioCar Initiative – a multi-university effort between the University of Guelph, University of Toronto, University of Waterloo and University of Windsor.

The BioCar Initiative is an Ontario government-funded project designed to advance the use of more plant-based materials in the auto and agricultural industries. Ford holds a spot on BioCar's advisory board and directs some of the project's automotive research with biomaterials.

Issues on the working block include:

• Moisture absorption: Natural fiber-reinforced plastics are more likely to absorb moisture over time, causing functional and durability concerns.
• Odor: Injection molding at high temperatures with a natural fiber-reinforced plastic emits an undesirable odor.
• Decomposition: PLA is designed to decompose quickly, but researchers want to make sure it will last the lifetime of a vehicle before that decomposition process starts.

Experimentation with nano filler materials in plastic composites is still on Ford's research screen, too. Nano fillers have the potential to reduce weight while increasing strength. Early testing shows, in fact, that a plastic reinforced with 5 percent nano filler instead of the typical 30 percent glass filler has strength and lightweight properties that are better than glass. The big roadblock all nano researchers are facing today, however, is how to uniformly exfoliate or disperse the nano material within the composite so that weak spots do not occur.

Here today
Although increased usage of bio-based materials in plastics is still in the advanced research phase, Ford has already made great inroads with other bio-based, reclaimed and recycled materials that are in Ford, Lincoln and Mercury vehicles today. They include:

• Soy-based polyurethane foams on the seat cushions and seatbacks, now in production on the Ford Mustang, Expedition, F-150, Focus, Escape, Escape Hybrid, Mercury Mariner and Lincoln Navigator and Lincoln MKS. More than 1.5 million Ford, Lincoln and Mercury vehicles on the road today have soy-foam seats, which equates to a reduction in petroleum oil usage of approximately 1.5 million pounds. This year, Ford has expanded its soy-foam portfolio to include the industry's first application of a soy-foam headliner on the 2010 Ford Escape and Mercury Mariner for a 25 percent weight savings over a traditional glass-mat headliner.
• Underbody systems, such as aerodynamic shields, splash shields and radiator air deflector shields, made from post-consumer recycled resins such as detergent bottles, tires and battery casings, diverting between 25 and 30 million pounds of plastic from landfills.
• 100 percent postindustrial recycled yarns in seat fabrics on vehicles such as the Ford Escape. The 2010 Ford Fusion and Mercury Milan Hybrids feature 85 percent postindustrial yarns and 15 percent solution-dyed yarns. The 100 percent usage represents a 64 percent reduction in energy consumption and a 60 percent reduction in CO2 emissions.
• In addition, Ford also has led the way for other industries to capitalize on its greener material technologies, licensing its soy-based foam to companies such as Deere & Company for agricultural applications. Ford researchers also continue to welcome biomaterial discussions with other non-auto-related manufacturers of items ranging from child car seats to furniture.