All Hands on DECS

Lear Corp. will manufacture seats within two years for two U.S. production vehicles using new technology that will cut the weight of the foam in half while making the seats more recyclable, comfortable and environmentally friendly.

Lear is preparing to launch its Dynamic Environmental Comfort System (DECS) seat, which represents a radical new approach to seat construction.

Traditionally, one piece of petroleum-based polyurethane foam is attached to a metallic mesh and then integrated into the metal seat frame, Ashford Galbreath, Lear's director-advanced materials and comfort engineering, says at the SAE World Congress, held recently in Detroit.

The DECS approach replaces the metallic mesh with foam layers of varying rigidity.

The first “durability” layer, attached directly to the seat-bottom frame, is made of expanded polypropylene. On top of that is the “dynamic comfort” layer made of Soyfoam, a soft, formable material manufactured from soybean oil that is quickly ramping up in automotive seat applications.

Converting petroleum into polyol for use as polyurethane foam produces carbon dioxide.

But converting soybean oil to polyol for Soyfoam produces no CO2, requires 60% less conversion energy and reduces emissions of volatile organic compounds by two-thirds vs. petroleum, Galbreath says.

The third “tactile comfort” layer in the DECS seat consists of polyester foam, and the finish surface also can be made of whatever the customer wants — polyester, leather, etc.

Or, Lear offers up bio-based fabric made from polylactic acid. Galbreath says any starchy crop can be converted easily into sugar, then spun into fiber for weaving into seat fabric.

Here at the SAE World Congress, Lear unveils a DECS prototype with a handsome, durable fabric produced entirely from recycled corn husks. The material is 100% compostable.

And unlike conventional polyurethane foam, all the materials used in DECS are easily recycled after the life of the vehicle, Galbreath says.

Despite eliminating the metallic mesh inside, the DECS seat boosts dynamic energy management 20%, Galbreath says.

Without being specific, he says the DECS concept is cost competitive with conventional seat technology, while offering more comfort.

For every new seat program, Lear is quoting the DECS technology to potential customers, Galbreath says.

Although the complete DECS approach will not appear in production vehicles until 2010, he says certain European vehicles and the Ford 500 (now Taurus) began using expanded polypropylene in 2006.

Another nifty feature of DECS allows interchangeable panels for the seat surface, such as a plastic container for the passenger seat to hold drinks, a purse or small electronic devices, or a plastic pen to hold small pets.

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