Advancing structural composites

Industry experts address the opportunities and challenges involved with moving toward composite-intensive vehicles, including Nissan's effort to produce a high-volume, fully recyclable composite liftgate with low metal content.

Composite structural closures are not new to the automotive industry. There are many types of composites panels that have been utilized by various OEMs, including fiberglass, carbon fiber, resin transfer molding (RTM), sheet molding compound (SMC), and injection molding. Each process has its advantages and disadvantages for material cost, tooling cost, dimensional stability, recyclability, processing time, and surface finish. An OEM will decide one method over another depending on the vehicle and structure, according to researchers from Nissan Technical Center NA, who participated in the “Automotive Composites” technical session at SAE 2014 World Congress.

Thermoset material systems are advantageous for low-volume applications due to low tooling cost. These are often the first choice for a new vehicle class or a specialty vehicle/trim based on an existing platform. Because these processes rely on extended cycle times for the resin curing process, the cost to apply to high-volume vehicles becomes prohibitive.