Name: PU Foam Core for Sandwich Panels & Composite Parts
Brand: RaxPanel
Availability: MadeToOrder

PU Foam Core

Polyurethane (PU) foam core is a rigid, closed-cell structural foam used as a lightweight core material in composite sandwich panels. Produced by reacting polyisocyanate with polyol in the presence of a blowing agent, PU foam forms a 90–97% closed-cell structure that delivers excellent thermal insulation, moisture resistance, and mechanical support at low density.

PU foam cores offer compressive strengths from 100 kPa to 500 kPa at densities of 30–60 kg/m³, with thermal conductivity as low as 0.020–0.028 W/m·K. The material maintains dimensional stability across a wide temperature range (-50°C to +75°C) and exhibits very low water absorption, making it suitable for insulated transport, cold storage, and building panels.

PU foam bonds readily with FRP, aluminum, steel, and plywood skins using polyurethane adhesives. It is compatible with vacuum infusion, hand lay-up, and continuous panel lamination processes. Typical applications include refrigerated truck and trailer bodies, RV and camper walls, insulated building panels, marine buoyancy, and modular construction.

RaxPanel: Your Trusted PU Foam Core Supplier

RaxPanel supplies polyurethane (PU) foam cores for insulated sandwich panels used in refrigerated transport, cold storage, RV construction, and building insulation. Our PU foam is formulated for low thermal conductivity, high closed-cell content, and consistent density across each block.

Our PU foam cores are available with:

Density grades from 30 to 60 kg/m³
Thermal conductivity as low as 0.020 W/m·K
Compressive strengths from 100 to 500 kPa
Custom block and sheet dimensions for panel lamination
Compatibility with FRP, aluminum, and steel skins

Every production batch is tested for density, compressive strength, thermal conductivity, and closed-cell content. Contact our engineering team to discuss density grade, dimensions, and order volume for your project.

Data Sheet
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Parameter Category	Parameter	Value	Test Standard
General Properties	Material Type	Rigid Polyurethane (PU) Foam	–
	Cell Structure	Closed-Cell (90–97%)	–
	Density	30–60 kg/m³	ISO 845
	Maximum Block Size	2400 × 1200 mm	–
	Thickness Range	10–150 mm	–
Thermal Properties	Thermal Conductivity	0.020–0.028 W/m·K	ISO 8301
	Operating Temperature	-50°C to +75°C	–
Mechanical Properties	Compressive Strength	100–500 kPa	ISO 844
	Tensile Strength	200–600 kPa	ISO 1798
	Shear Strength	100–300 kPa	ISO 1922
	Compressive Modulus	3–20 MPa	ISO 844
Physical Properties	Water Absorption	≤ 3% by volume	ISO 2896
	Closed-Cell Content	≥ 90%	–
	Dimensional Stability	≤ 2.0% change	ISO 2796
	Adhesion Compatibility	FRP, aluminum, steel, plywood (PU adhesive)	–

Related Products

Aramid Honeycomb Core

PC Honeycomb Core

PET Foam Core

PMI Foam Core

PP Honeycomb Core

PVC Foam Core

PU Foam Core Selection & Engineering Guide

Selecting the right PU foam core specification involves matching density, compressive strength, and thermal conductivity to your insulation and structural requirements. RaxPanel supplies polyurethane foam blocks and sheets for sandwich panel production in refrigerated transport, cold storage, and building insulation.

Pro Tip: Density vs. Insulation Trade-off
Lower-density PU foam (30–35 kg/m³) delivers the best thermal insulation (λ as low as 0.020 W/m·K) for cold storage and building panels. Higher-density grades (50–60 kg/m³) provide greater compressive strength (up to 500 kPa) for load-bearing transport applications such as refrigerated truck floors.

1. How to Choose the Right Density Grade

Density governs the balance between insulation performance and mechanical strength. For insulated building panels and cold storage walls, 30–40 kg/m³ provides optimal thermal resistance. For refrigerated truck bodies and trailer floors that bear dynamic loads, 45–60 kg/m³ ensures adequate compressive and shear performance.

2. How Do Thermal and Mechanical Properties Compare?

Property	Low Density (30–35 kg/m³)	High Density (50–60 kg/m³)
Thermal Conductivity	0.020–0.024 W/m·K	0.024–0.028 W/m·K
Compressive Strength	100–200 kPa	300–500 kPa
Best For	Insulated walls, roofs, cold storage	Truck floors, trailer bodies, load-bearing panels

3. Which Skin Material and Bonding Method to Use?

Skin and Bonding Options:

FRP Skins: Bonded with polyurethane adhesive for RV walls and refrigerated truck bodies.
Aluminum Skins: Used with continuous panel lamination for insulated building panels.
Steel Skins: Bonded for heavy-duty trailer and container panels.

4. Where Are PU Foam Cores Most Commonly Used?

Transport & Cold Chain

Refrigerated truck and trailer bodies, cold storage rooms, reefer containers, and RV/camper walls.

Building & Industrial

Insulated wall and roof panels, modular construction, marine buoyancy, and pipe insulation.

5. How to Cut, Machine, and Laminate PU Foam Cores

PU foam blocks can be cut with hot-wire cutters, band saws, or CNC routing to achieve precise panel dimensions. For sandwich panel production, apply polyurethane adhesive to both foam and skin surfaces, press under controlled pressure, and cure at ambient temperature. Store foam blocks in dry conditions away from direct sunlight before lamination.

Frequently Asked Questions (FAQS)

1. What density grades and block sizes are available for PU foam cores?

Density grades range from 30 to 60 kg/m³. Standard block sizes are up to 2400 × 1200 mm with thicknesses from 10 mm to 150 mm. Custom cuts and CNC-machined shapes are available on request.

2. What thermal conductivity can PU foam cores achieve?

PU foam cores achieve thermal conductivity as low as 0.020–0.028 W/m·K, depending on density and blowing agent. Lower-density grades generally provide better insulation performance.

3. What compressive strength can PU foam cores achieve?

Compressive strength ranges from 100 kPa (at 30 kg/m³) to 500 kPa (at 60 kg/m³). Select the density grade based on whether the panel must bear only static loads (insulated walls) or dynamic loads (truck floors).

4. How does PU foam compare to XPS and PET foam cores?

PU foam offers the lowest thermal conductivity of the three, making it the best choice for cold chain and insulation applications. XPS provides higher compressive strength at similar density. PET foam offers better mechanical performance and recyclability for structural composites.

5. Can PU foam cores be laminated with FRP and aluminum skins?

Yes. PU foam bonds readily with FRP, aluminum, steel, and plywood skins using polyurethane or epoxy adhesives. The closed-cell surface provides good adhesive compatibility for both batch and continuous lamination processes.

6. What temperature range can PU foam cores withstand?

PU foam maintains stable performance from -50°C to +75°C, making it suitable for freezer and cold storage applications. Prolonged exposure above 75°C is not recommended; for higher-temperature applications, consider PIR (polyisocyanurate) foam variants.

7. How are PU foam block shipments packaged for export?

PU foam blocks are stacked on wooden pallets, wrapped in PE film for moisture protection, and secured with straps. Pre-cut panels receive additional edge protection to prevent damage during container shipping.