Industry manufacturers and OEMs are testing both new and proven technologies as they add more composite components to vehicles.

Honeycomb composite materials, often made by layering a paper honeycomb core between two thin fiberglass mats, are a well-known technology for automotive applications. OEMs have been using them for more than two decades for interior components like load floors, sunroof covers and the package shelves behind vehicles’ back seats.

But now honeycomb composites are moving outside of the interior. In China, a soon-to-be-launched electric vehicle features a hood made from a honeycomb composite with a Class A finish. A honeycomb composite is also incorporated in the removable “My Sky” roof panels in the Jeep Renegade. And the roof module for the Smart Fortwo, a two-seater city car from Daimler AG’s Smart Division, demonstrates just why honeycomb composites are drawing automakers’ attention; it is about 30 percent lighter than a previous version of the roof but has the same strength and rigidity.

Car and truck manufacturers’ ongoing interest in incorporating more composite components into their vehicles is spurring market growth, and it extends well beyond honeycomb materials. Grand View Research predicts that the global automotive composites industry will reach a value of $11.62 billion by 2025, with an annual growth rate of 6.8 percent over the next seven years.

But the road to wider adoption of composites isn’t straight and smooth; there are still some difficult curves to navigate. Although composite materials can provide significant advantages in light weighting, corrosion resistance, design innovation and parts consolidation, composites manufacturers must compete with manufacturers of aluminum and steel parts to maintain or increase their share of the parts business. At the same time, they must find ways to decrease material costs, to speed production for larger volumes and to manufacture components that are able to meet OEMs’ exacting specifications.

Composites manufacturers are continually making improvements. One example is fiberglass mats, which are used for exterior parts but are not smooth enough for paint application right out of the mold. “You have to fill it and buff it and sand it and smooth it before you can get the Class A finish, and that is an expensive and time-consuming process,” says Dan Rozelman, senior technical sales specialist in the composites and advanced applications group for equipment manufacturer Hennecke Inc.
Resin injection molding (RIM) coating technology promises to change that. With RIM, the part is put into a closed mold with a small gap left above the surface. “Then we inject polyurethane over the top to make a Class A, out-of-mold, finished part,” Rozelman explains.