Polyurethane Chemistry The chemistry behind the lightweight design of the new Grand Cherokee L
USA — The new composite tunnel reinforcement of the Grand Cherokee L is 40 percent lighter than the previous version. For this achievement, the lightweight design developed by BASF; L&L Products as well as Stellantis was awarded the Altair Enlighten Award.
The three companies BASF, L&L Products and Stellantis have been recognised for lightweighting success on the composite tunnel for the 2021 Jeep Grand Cherokee L. The vehicle, which launched in May, just won the prestigious Altair Enlighten Award for achievements in vehicle weight savings.
While researching opportunities to reduce mass and improve durability without compromising safety performance, the transmission mounting system (TMS) was one area of focus. The composite tunnel reinforcement (CTR) is located on the underside of the vehicle and is part of the overall TMS. In the event a vehicle collides slightly with an opposing vehicle for example, the CTR transfers the energy load from the outer rail to the transmission mount crossmember, improving performance in the field and in the Insurance Institute for Highway Safety (IIHS) standards small offset rigid barrier test.
The use of Continuous Composite Systems (CCS) pultrusion technology along with polyurethane chemistry from BASF were key factors in the success of the CTR. CCS combines a fiber-reinforced pultruded composite carrier with highly engineered sealants and adhesives in a two-dimensional profile. This is a continuous process used to create straight or curved composite profiles reinforced with continuous fibers and mats. The system is designed to provide strength, stiffness, and rigidity to a lightweight structure.
This was also the first application for L&L Products using their CCS technology and BASF’s Elastocoat 74850 polyurethane pultrusion system.