Comfort has many meanings in the auto industry.
There's the feeling when you first get behind the wheel of a new car, and the sense of the way the seat conforms to your body; the sensation - or lack of sensation - after two or three hours behind the wheel on a long trip; and most importantly for the companies that make them, the comfort of making money on producing those seats.
And now those companies also are starting to provide comfort in environmental terms, launching production of seats using polyurethane foam with a blend that includes resin from soybeans.
``This reduces our dependency on petroleum, but also reduces our sensitivity to petroleum price fluctuations,'' said Ash Galbreath, director of environmental comfort engineering for auto supplier Lear Corp. of Southfield, Mich.
The pressure to turn out better and more appealing auto interiors, combined with the rising cost of doing business, is leading companies like Lear and its competitors to rethink the way they use standard materials.
Even something that appears as simple as the cushion inside a car seat has been re-engineeered and improved.
A decade ago, seat makers would have addressed complaints about uncomfortable seats by adding more foam, Galbreath said. Now they have learned more about how to layer high density PU blends or alter their shape to be soft in one area and maintain stiffness in another.
They bring in consumers to test seats and make seats capable of withstanding up to 100,000 miles of driving.
``We're developing new ways to use engineered layers,'' he said.
It is not simply a matter of fixing what is not broken. Urethane is facing increased competition from polypropylene foams and other materials. Carmakers have phased out urethane's use for padding in door panels and instrument panels of even most midpriced cars in an attempt to cut costs.
Automakers anxious to squeeze additional space into car interiors want seats that are slim but still comfortable.
``There's only so much that you can do with standard polyurethane,'' Galbreath said.
The current soy breakthrough is not exactly new. Henry Ford began experimenting with soybean-based plastics in 1929, though much of that work went by the wayside after World War II.
The current resurgence in soybeans for PU foam started about five years ago, when carmakers and suppliers alike saw the potential for a raw material that was environmentally friendly and less prone to price hikes than petroleum.
When Plymouth, Mich.-based Johnson Controls Inc.'s auto unit first began investigating the potential for bio-based resins, soybeans made sense, said David Kingston, executive director of complete seat products and business development.
Soybeans are grown nearly everywhere in North America.
In addition, soy-based resins come from an oil that is a byproduct of food production, so unlike ethanol - which requires corn and other feedstocks to be taken out of the food pipeline, raising overall prices - soy resin actually uses a waste product, he noted.
``We're trying to reduce our need for petroleum-based product,'' Kingston said. ``We're trying to be more sustainable. It really started there.''
Lear's SoyFoam is going into new models of Ford Motor Co.'s Mustang.
JCI launched production of its soy foam blend seats for North American and Japanese-based car manufacturers in August. The company would not identify specific models or customers.
The blends both companies are using replace 5 percent of the petroleum with soy oil for seats. That does not sound like a lot, Kingston said, but it adds up quickly at auto-production volumes. JCI molds more than 100 million pounds of PU foam annually. If soy foam were used in all those pads, the company would reduce its use of petroleum-based foam by ``several million pounds.''
A higher percentage of soy foam can go into higher-density foam, such as on headrests and arm pads, Galbreath said, with as much as 28 percent of the PU coming from soy.
Soy also offers automakers a chance to improve their environmental status. Galbreath noted a sustainability study that listed a 75 percent improvement in carbon dioxide emissions with soy-based foam, compared with petroleum-based foam.
But soy foam is not the only new development in urethanes for the auto industry. Lear and JCI have been using higher-density foams that will allow them to make thinner seats, but still retain the same comfort level. JCI has a concept ``vibratech'' foam that can be engineered into the seats of a car. As an example of the technology, think of a sports car that carries its rumbling feeling to a driver cruising down the road.
Future development should see the companies increasing the soy content in its foams beyond the current 5 percent, Kingston said.
``I don't see polyurethane foam completely going away,'' Galbreath said. ``It's useful, it's durable, it's proven - but we need to think about how to improve it in terms of renewability.''