Top choice for general use: Fiberglass (FRP) + Polyurethane
With a thermal conductivity just 1/100 to 1/1000 that of metal, this combination offers excellent insulation. It is 15% lighter than steel plating-allowing for hundreds of kilograms of additional payload-and is resistant to acid and alkali corrosion. It is easy to clean, and minor damage can be repaired without leaving obvious traces. It offers a lower total cost of ownership over the long term and is suitable for the vast majority of cold-chain transport scenarios.
Options for specialized scenarios
Transporting seafood or highly corrosive goods: Prioritize a combination of fiberglass outer skin and stainless steel inner skin; this maximizes corrosion resistance and meets food-grade hygiene standards.
Short-haul transport of fruits and vegetables with basic requirements: A cost-effective combination of color-coated steel and polystyrene (EPS) panels is a viable choice; it lowers manufacturing costs while meeting basic insulation needs.
Prioritizing extreme lightweighting: Aluminum alloy can be used to further reduce the vehicle's curb weight and improve fuel economy.