FRP Sandwich vs Polyurethane Foam Injection: Choosing the Right Refrigerated Truck Body

When investing in a refrigerated truck body, one of the most important decisions is the manufacturing process. Two methods dominate the market: FRP (fiberglass-reinforced plastic) sandwich panel construction and polyurethane foam injection. Each has distinct advantages, and the right choice depends on your specific needs.

Understanding the Two Processes

FRP Sandwich Panel Construction (Dry Bonding)

In the dry-bonding process, pre-cut rigid insulation boards — typically polyurethane foam or extruded polystyrene — are sandwiched between two layers of FRP. These layers are bonded together with structural adhesive under a hydraulic press, creating a rigid composite panel.

Process highlights:

Polyurethane Foam Injection (In-Situ Foaming)

In this process, the FRP inner and outer skins are placed in a mold, and liquid polyurethane is injected into the cavity. The liquid expands and cures into rigid foam, bonding to both skins and filling every space.

Process highlights:

Comparative Analysis

Which One Should You Choose?

Choose FRP Sandwich Construction When:

Choose Polyurethane Foam Injection When:

The Truth About Both Methods

Both FRP sandwich construction and polyurethane foam injection produce high-quality refrigerated truck bodies when properly manufactured. The thermal performance difference between the two is minimal in practice — a well-built sandwich panel body performs as well as a foam-injected body in most operating conditions.

The more important factors are:

1. Manufacturer quality control: Poor execution ruins either process
2. Panel thickness: 80mm vs 60mm makes a bigger difference than the process
3. Assembly quality: Corner joints, door frames, and seals matter more than the panel itself
4. Refrigeration unit matching: The body is only half the system

Conclusion

Neither method is universally superior. Choose FRP sandwich construction when you need custom configurations, flexibility, and repairability. Choose polyurethane foam injection when you need standardized dimensions, maximum structural strength, and production speed. Either way, work with an experienced manufacturer who can help match the body construction to your specific cold chain requirements.

Many manufacturers, including those serving the Chinese cold chain market, offer both processes and can recommend the best approach for your application.