Lightweight Composite Seat Back Developed by Covestro and Chinese Automaker GAC

A lightweight thermoplastic composite seat back that also is touted for its sustainability is well underway through a partnership between Covestro and the R&D Center of Guangzhou Automobile Group Co Ltd. (GAC). This is for the Chinese car manufacturer's latest concept electric car, the ENO.146, which recently made its debut at the Guangzhou International Automobile Exhibition.

GAC describes the ENO.146 as one of the most aerodynamically efficient vehicles in the world, thanks to a drag coefficient of only 0.146 (hence the name) and a NEDC (New European Driving Cycle) range of 1,000 kilometers (621.37 miles). While a fully aerodynamic design is key to achieving such performance goals, the GAC R&D Center also uses lightweight and sustainable materials to reduce the weight of the car while raising the bar for sustainability. Covestro’s Maezio thermoplastic composite material is one of them. The Maezio brand of CFRTP composites are based on continuous carbon fibers impregnated with thermoplastics like polycarbonate and TPU.

The backrests of the two front seats of the concept car are made of Maezio CFRTP. It is estimated that the composite seat backrest can save up to 50 percent in weight compared to typical metal constructions.

Says Lisa Ketelsen, head of Covestro's thermoplastic composites business: “Seats in the passenger compartment are an ideal target for weight savings, as they are among the heaviest parts there. Fiber-reinforced composites are the ideal material for lightweight automotive construction, but Maezio can further simplify molding and streamline the manufacturing process.”

Whereas a seat with a metal backrest, fittings and other attachments add to the complexity of production and assembly, parts and functions made with thermoplastic Maezio can be consolidated by injection molding. Functional structures are incorporated into the mold for shaping the backrest, reducing the number of parts and materials.

Says Zhang Fan, v.p. of the GAC R&D Center: “Mobility trends such as electrification and autonomous driving are redefining the role and function of car interiors. There is a growing need for material solutions that are lightweight and sustainable while opening up ways to create new user experiences ranging from visual to tactile feedback.”

From the color, material, finish (CMF) perspective, the design of the ENO.146’s vehicle interior was inspired by nature. According to GAC R&D’s chief designer Stephen Chen, the choice of green color and various sustainable materials is intended to recreate the ambience of a lake with lotus flowers. The surface pattern of the front of the seat, for example, is designed to resemble that of lotus leaves. “The backrest must fit into this design concept as a visible component, so the material must have a natural look and feel and high aesthetic value, and it must also be recyclable,” says Chen.

As such, Maezio is an excellent fit. The thermoplastic composite material can be cut and shaped at will to be reused at the end of its service life, giving it a unique marble-like appearance and a high- quality look and feel, making it a sustainable material choice that fits perfectly into the design concept of the vehicle.