Advancing Composite 

Foam Core Technology

ISO-CF® Composite Foam Core

ISO-CF® is Kingspan Insulation's structural foam core product within its polyisocyanurate line of products, specifically designed for use within composite structures. Kingspan ISO-CF polyisocyanurate rigid foam is a material ideal for composite panel applications using substrates such as metal, fiber-and-resin, or composites that are laid over the polyisocyanurate foam. Kingspan’s ISO-CF densities range from 2 to 6 pcf. Polyisocyanurate (polyiso or PIR) is a modified polyurethane, achieving improved physical properties such as dimensional stability. Applications include structural composites that require an insulation value as well as a rigidity, dimensional stability, water resistance, and long-term performance. Kingspan produces ISO-CF as continuous foam bunstock with the ability to custom size the bun - - which we then cut into custom thicknesses, widths, and lengths (for example, 24-foot panels or blocks) or Special Cut shapes to very high tolerances. Kingspan utilizes a variety of CAD-based cutting and shaping equipment, controlled by highly trained technicians to fabricate customized single or mass-produced shapes and special parts. 

Kingspan's high-volume production and fabrication abilities plus extensive inventory ensure quick, on-time deliveries at high capacity.

Common Applications:

  • Aerospace/aircraft 
  • Marine (ship, boat, platforms) 
  • Transportation (truck, rail)
  • Construction (building, architectural)
  • Wind/bioenergy

Light-weight ISO-CF at 2.0 pcf density has an excellent compressive strength at 25 psi (174 kpa) achieving strength to weight ratios higher than alternative structural core products. Improved flexibility characteristics can also be achieved in applications where it may be an important property. ISO-CF is also available in higher densities of 2.5, 3.0, 4.0, and 6.0 lb/ft3, each with increasingly improved strength profiles. ISO-CF is useful in foam core applications from -297 to +300°F (-183 to +149°C). ISO-CF/HT is useful in higher temperature applications up to 350°F (177°C) continuous, and 375° (190°C) intermittent. 

Our proprietary production process utilizes hydrocarbon blowing agents creating a portfolio of ISO-CF products with an extremely low Global Warming Potential (GWP). ISO-CF is independently tested and audited, and is listed with FM as a Specification Tested Identified Component - Combustible Core for Insulated Building Panels under FM 4880. 

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ISO-CF has higher thermal efficiency than competing foam cores, which can offer benefits sometimes not considered. For instance, ISO-CF based composite panels used in transportation containers will require less additional insulation. Similarly, composite panels using ISO-CF on, for example transportation containers, ships, and boats, may offer warmer, or cooler, environments than would be otherwise be achieved with other composite cores - - while offering comparable or superior strength characteristics. Compliance with ASTM C591-15 ensures certain physical properties were tested over the various temperatures encountered in applications.


Water absorption within foam cores can compromise physical properties. ISO-CF’s excellent resistance to water absorption (0.5%) as measured in accordance with Test Method ASTM C272 helps ensure long-term performance. In the unlikely event of a failure of the outer laminates, ISO-CF offers an additional layer of protection. Note that water absorption for different foam cores is often measured by different ASTM Test Methods, making comparisons challenging. For instance, ISO-CF’s WA of 0.5% was based on C272’s 24 hour period of immersion; comparable foam cores can be measured from as little as a 2 hour immersion period.

For optimum performance and longevity, some composite foam core systems must be designed to additionally control condensation. This requires a combination of thermal control and water vapor permeability. No other foam core offers ISO-CF’s combination of high thermal efficiency and low permeability.


  • Composite panels with substrates (e.g. metal, fiber/resin, poly/plastic, or composites laid-overEPS cores)
  • Cores for Structural Insulated Panels (SIPS)
  • Laminated panels / Sandwich panels
  • Transportation/vehicle walls and floors
  • Customized form molds for concrete arches and other shapes in building applications
  • Special Cuts for customized applications
  • EPS/Polyiso sandwich cores
  • Cores for spa covers and similar applications