A new seating system debuting in the 2010 Ford Fusion Hybrid is eco-complimentary, lightweight, and helps to cool the vehicle's hybrid battery.
The Dynamic Environmental Comfort System (DECS) is Lear's descriptor for its innovative seating system with "more than 28 current patents, patents pending, and trade secrets covering the layered design, safety, construction, modeling, acoustic, customization, and component-integration aspects," according to Ash Galbreath, Director of Advanced Materials and Comfort Engineering for Lear's Global Seating Division.
In the research and development stage for more than two years, the DECS seat is comprised of four layers. The "durability layer" uses 100% recyclable expanded polypropylene (EPP). "This area in seating typically uses polyurethane reinforced with in-molded wire frame, felt, or fabric inserts to improve durability, but the DECS design eliminates the need for those items and facilitates end-of-life vehicle reuse," said Galbreath.
Lear's proprietary ComforTec comfort engineering process optimizes the comfort profile that is molded into the durability layer. "We worked for about a year to apply the ComforTec process to the layered construction, define layer characteristics, and create algorithms for the comfort contour design to the point of making a workable design," said Galbreath.
The ComforTec process enables engineers to tune material thickness, density, and hardness. "Instead of providing a common support structure, we can use multiple frames and that eliminates the need to modify the foam in order to protect it from the frame with in-molded felts and fabric layers," explained Galbreath.
The DECS "dynamic comfort layer" is Lear's SoyFoam, a soft, flexible foam product made from renewable resource-derived soybean oil polyol. "This is traditionally made from petroleum-derived foam with 67% higher volatile organic compound (VOC) emissions than SoyFoam," Galbreath said.
The "tactile comfort layer" uses nonwoven polyester that is 100% recyclable and non-VOC-emitting. This layer is traditionally made from petroleum-derived polyurethane, said Galbreath.
The final "visual aesthetic layer" can be made from fabric or leather. "One fabric option uses recycled content/recyclable eco-friendly polyester fabric made from pre- and post-consumer waste materials that reduce petroleum dependency, shorten the fabric manufacturing process, and use less water in the dyeing process. Other options include fabric derived from bio-based fibers (i.e., corn-derived polylatic acid) and chrome-free leather that is processed using organic-based tannins instead of chrome salts," said Galbreath.
With a 16% mass reduction—representing more than 1 kg (2.2 lb) of weight savings—compared to the traditional rear seat in the Ford Fusion, the DECS seat in the Fusion Hybrid is minus certain components. "In this case, we are replacing an in-molded wire frame structure and a portion of the polyurethane foam with EPP," said Galbreath. The rear seat also incorporates an air duct for the car's nickel-metal hydride battery.
"Ford opted for the DECS seat in the Fusion Hybrid because it meets the airflow specifications for the high-voltage battery, while allowing us to cost-effectively share common hardware with the gasoline Fusion variant and maintain the rear seat comfort, ergonomics, and room that customers expect," according to Gil Portalatin, Hybrid Propulsion System Applications Manager at Ford Motor Co.
DECS manufacturing means replacing certain conventional polyurethane molding technology with material forming methods, such as compression and steam-chest molding. "The durability layer is molded in a steam-chest operation that joins EPP beads together that are formed in a separate reaction to expand them to the correct density. All of the layers are then assembled to either a hydroformed or stamped metal frame or designed for direct vehicle floor pan attachment," explained Galbreath.