New Epoxy Resin Will Make BMW 7-Series 130 kg Lighter

In the name of lighter, more cost effective vehicles, BMW Group has recently approved a new EPIKOTE epoxy resin system for use in volume production of structural composite parts for their new BMW 7-Series.

Developed by Hexion Inc., EPIKOTE Resin TRAC 06000 with EPIKURE Curing Agent TRAC 06130 was designed to match all of BMW’s performance and production speed requirements in liquid compression molding (LCM) and high-pressure resin transfer molding (HP-RTM) processing.

This lightweight fiber epoxy door and window frame won Hexion the "People’s Choice" Award for “Most Innovative Composite Part” at the annual Society of Plastics Engineers ACCE in 2014 for its use of a EPIKOTE 04695-1/EPIKURE 05357 resin system, carbon fiber and polyester fiber. The door weighed only 5.5 kg versus the 15 kg standard series door. (Image courtesy Hexion Inc.)

The epoxy cures in less than two minutes and will act as a lightweight replacement material for traditional metals.

BMW uses Hexion resins in their carbon-fiber-reinforced polymer (CFRP) roof cross-members, center tunnels and sills. The resins are also used in a 2.7 m arc along the roofline of the carbon core body structure manufactured by LCM and HP-RTM.

The use of CFRP for structural elements of the passenger cell is intended to increase the overall strength and torsional and bending stiffness of the cell. For this application, the configuration of sheet metal elements can also be adjusted to reduce the weight of the body.

According to Hexion, the weight of the new 7-Series has been reduced by 130 kg (287 lbs) compared to previous models. The unladen weight of a 2016 G11 7-Series is 1990 kg (3,869.1 lbs).

The BMW 7 Series 750Li xDrive. (Image courtesy BMW Group.)

Examples of the new BMW 7-Series and other automotive composite parts were on display at Hexion’s booth during the JEC World 2016 composites show and conferences from March 8-10 in Paris, France.

For more information, visit Hexion’s website.