Why Specify Composites?
9 compelling reasons to specify composites
Composites offer many advantages compared to traditional materials, including:
- Substantial weight reduction: FRP composites are typically 30-40% lighter than steel parts of equal strength.
Composite parts can be designed to carry the same loads as steel. Parts are generally molded at minimum thickness to reduce weight and minimize molding cycle time. Structure is achieved through proper section design to add increased strength and stiffness to localized areas as required. Automotive closure panels are generally two-piece designs consisting of a Class "A" cosmetic skin backed by a non-appearance structural reinforcement panel.
- Lowered manufacturing complexity: Finished assemblies with fewer parts cut manufacturing costs and often accelerate design completion and model introduction.
A single composite molding can take the place of up to 15-20 individual steel components and fasteners. With fewer components to procure, inventory and assemble the net result is tighter tolerances, better fit & finish and reduced labor cost.
- Reduced tooling cost: Tooling for composite parts can be as much as 80% less than comparable metal parts.
Steel parts often require a series of stamping dies to produce a desired shape in addition to multiple components that must be subsequently assembled. In most cases, one or two molds and presses take the place of entire multi-station stamping lines. Bottom line: lower cost, tighter tolerances and less assembly required.
- Unparalleled damage resistance: Composites' dent and ding resistance is far superior to that of steel, aluminum and thermoplastic panels.
Composites do not dent nor ding. Their C.L.T.E. is very similar to steel which allows them to maintain excellent fit & finish over a wide range of temperatures. They do not embrittle when exposed to cold temperatures nor will they melt in the presence of extreme heat as do thermoplastics.
- Unrivaled corrosion resistance: FRP composites are superior in corrosion resistance for any application.
Composites do not rust nor corrode when exposed to moisture and road salt and will literally outlast most of the steel components on a vehicle. Their inherent chemical resistance and dimensional stability make them well suited for engine components such as valve covers and oil pans.
- Better internal damping: Leads directly to reduced noise, vibration and harshness (NVH).
Fewer parts mean fewer chances for squeaks and rattles. Composites are inherently better sound insulators than steel.
- Improved design flexibility: Unlike metals, composites offer a limitless "depth-of-draw" range.
Stamped metals get thinner as they are drawn to form vertical walls; whereas, composites offer the ability to maintain a constant cross-sectional thickness over the entire part. Many shapes that are impossible or economically prohibitive to form in steel and aluminum can be produced with relative ease in composites.
- Cost-effective solutions: Lower composite investment costs satisfy automakers' trends toward reduced builds per model.
With the current trend towards niche marketing and frequent design "freshening" production runs of closure panels are typically shorter. Thus, it is advantageous to minimize both the number and cost of the tooling as it will be amortized over fewer units.
- Comparable aesthetics: Toughened SMC resin provides "first-time-through" processing comparable to steel.
The surface smoothness of most composites is equal or better than the steel parts surrounding them. Composite panels are generally assembled onto the vehicle and painted on-line with their steel counterparts. Recent advances in formulation chemistry first run capability is now considered to be equal or better than steel by some OEMs. On the finished vehicle, composite parts are visually indistinguishable from steel and aluminum.
Examples of Leading Edge Composite Technology
- 2007 DCX Jeep Wrangler Removable Hardtop Assembly – Multi-piece SMC composite: Meridian Automotive Systems
- 2007 Corvette Z06 – Many composite components: Molded Fiber Glass, Meridian Automotive Systems, PlasanUSA
- 2007 Saturn Sky – Many composite components: Meridian Automotive Systems, Molded Fiber Glass
- 2007 OPEL Zafira Roof Components – Baydur® polyurethane components: Bayer MaterialScience LLC