Old Tires & Soy Seed Ford's Gaskets

Use of natural and waste materials continues to grow impressively at Ford Motor Co. in Dearborn, Mich.

More than 2.2 million pounds of rubber from recycled tires have been made into seals and gaskets, and more than 210,000 used tires have been recycled. About 150,000 pounds of soy has been used to create the materials. The gaskets and seals are derived from 25 percent post-consumer, recycled tire particulate and 17 percent bio-renewable content from soy.

The green gaskets and seals are used on 11 2011-model-year vehicles, including the F-150, Escape, Mustang, Focus and Fiesta. As a nice bonus, the seals also offer a weight savings, with more than 1,675 tons of weight removed from Ford vehicles on the road.

The technical explanation is interesting. The polyurethane foam with recycled tire tread filler used in the engine gasket is lighter than the EPDM rubber it replaces. And the soy oil used as a feedstock for the polyol in the foam is significantly less dense than the hydrocarbon materials (such as ethylene glycol) it replaces.

"When it comes to finding a way to use more renewable and recyclable content, Ford and our suppliers are looking at every part of a vehicle," says Dr. Cynthia Flanigan, technical leader, Research and Innovation. "As long as an application meets our strict quality and performance standards, we all strive to get these sustainable materials on our vehicles."

Ford has had an aggressive program to develop natural feedstocks for many components in cars in recent years. Examples include soy foam seat cushions, wheat-straw-filled plastic, recycled resins for underbody systems, recycled yarns on seat covers, and natural-fiber plastic for interior components.

"Our team continues to develop new technologies that reduce our environmental footprint," says Dr. Debbie Mielewski, technical leader, Plastics. "We have already been successful in incorporating soy foam seats on all North American vehicles and are actively expanding the research front into a variety of new plastics and rubber areas."

The technical team started looking at soy-based polyurethane foams in 2001, Mielewski tells Design News. The first foam produced in the lab had a rancid odor, poor compression set, and poor mechanical properties. The chemical companies and most of the supply base pretty much ended looking at hydroxylated soybean oil as a component in automotive foams at that time.

"My group, formed in 2000, had a formulation chemist named Christine Perry who said, 'I think I can do it.' She went away and made hundreds of different formulations, and the whole 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 the Mustang in 2007.