The Future of Refrigerated Trailers
Wabash National’s prototype composite reefer trailer uses fiberglass, carbon fiber and resin in its panels, including the floor and supporting structure. It’s said to weigh and perform about 20% better than conventional temperature-controlled trailers. Photo: Wabash National
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Wabash National’s prototype composite reefer trailer uses fiberglass, carbon fiber and resin in its panels, including the floor and supporting structure. It’s said to weigh and perform about 20% better than conventional temperature-controlled trailers. Photo: Wabash National
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What will the refrigerated trailer of the future be made of? Strong, lightweight and corrosion-proof composites? Very possibly. Economical, efficient aluminum sheet-and-post design, like now? Yes, for a number of years yet. So say engineers engaged in designing and building temperature controlled trailers.
Today, these are made of sheet-and-post walls on floors supported by underbody crossmembers. Walls are sandwiches of inner and outer metal panels with aluminum posts inside the cavity, and the void is filled with polyurethane foam insulation. All components, including the foam, lend strength, and of course, the foam acts as insulation, limiting conduction of ambient heat and cold to the trailer’s interior. The thicker the walls and the amount of foam inside, the greater the vehicle’s “R” rating, and its ability to help the mechanical reefer unit maintain a desired temperature inside. But thicker walls also add tare weight and reduce payload capacity.
“I do see more use of non-metallic materials,” says Charlie Fetz, recently retired research and development engineer at Great Dane Trailer and author of a Future Truck paper on temperature controlled trailers for ATA’s Technology & Maintenance Council. “Aluminum is a great material, but it conducts heat. If they’re inside the wall cavity, the aluminum posts do contribute to heat conduction. Manufacturers minimize that with careful design.”
One way is to surround narrow posts with foam, minimizing the conduction of heat. One-inch posts inside a 2-inch wall, for example, allows room for injecting foam around the posts and throughout the wall cavities. Another way is to improve the foam’s efficiency, which manufacturers have repeatedly done over the years. Another round …Read the rest of this story
