South America
Performance Polymers

Structural Insulated Panels (SIPS)

Highly efficient thermal insulation with polyurethane – the right choice for Structural Insulation Panels (SIPS) Structural Insulated Panels (SIPS) are produced with polyurethane insulation foam sandwiched between Oriented Strand Board (OSB). U-values of 0.17 to 0.18W/m2K are currently achievable using a 150mm thick panel. Lower U-values are also possible by increasing the panel thickness.

Why insulate with polyurethane?

BASF Insulation Foam is a closed cell polyurethane foam used in many applications in the field of heat and cold protection due to its excellent thermal insulation properties.

This ‘made-to-measure insulant’ boasts extremely low thermal conductivity levels matched by no other conventional insulant.

Good mechanical properties and excellent adhesion of the wood and PU composite mean the material has a wide range of applications.



SIPS panels are normally produced in a horizontal heated press. The OSB facing material is pre-set into a restraining foaming jig which is then clamped by a press. Foam is then injected into the cavity between the two OSB faces. Injection time depends on a number of variables but is typically between 5 and 30 seconds.

Immediately after the injection cycle the foam starts to react and expand flowing through the cavity to reach a complete fill in around 2 minutes. An initial curing period of around 30 minutes (depending on panel thickness) is required before the SIPS panels has sufficient strength to be released from the press. At this stage the panel can be stacked and stored as appropriate in preparation for shipment to site.

Elastopor insulation foams are produced by reacting a liquid polyol component with a liquid polymeric isocyanate, Methylene Diphenyl di-Isocyanate (MDI), component in the presence of a blowing agent and other additives.

The mixed components then react exothermally to form a rigid thermosetting polymer and since the blowing agent evaporates during this exothermic reaction a rigid closed cell low density insulation product is created. Excellent insulation is achieved because the gas trapped within the closed cell structure has a very low thermal conductivity and there is minimal heat conduction through the solid cell walls due to the low density, where approximately 97% of the volume of the foam is trapped gas.

Elastopor insulation foam is produced using specially designed processing equipment capable of accurately metering the liquid components and mixing them together. The output rate of a the equipment is adjustable both in terms of the rate and the ratio of the components. The weight of foam dispensed during each foam injection is controlled by a timer.

Two basic types of machine are available:

Low Pressure Machines: Whereby the liquid components are pumped at relatively low pressures (less than 20 bar) to a dynamic mixer.

High Pressure Machines: Whereby the liquid components are pumped at a pressures around 150 bar and mixed at high velocity by an impingement method.

Typical applications

  • Cladding

  • Residential

  • Caravans

  • Commercial



  • Panels suitable for walls, roof and floor applications

Cost savings

  • Reduced construction times – possible to work outside

    and inside simultaneously
  • Off site manufacture gives additional design flexibility

  • Off site manufacture results in minimal waste on site

  • Off site manufacture reduces on-site labour costs


  • OSB facings produced by using timber from managed

  • Efficiency of insulation and method of construction results

    in lower energy costs
  • Air tight construction – 2.5 air changes per hour achieved

    during a self build; using SIPS construction it would be
    possible to reduce the number of air changes per hour to less than 1
  • BASF systems comply with the highest sustainability standards exhibiting:

  • Zero ODP (Ozone Depletion Potential)

    Less than 5 GWP (Global Warming Potential)


BASF co-operates with a range of equipment
suppliers and offers guidance to potentially interested companies.

Insulation physical properties

  Unit Measured value Method
Density – apparent overall  kg/m³ 42.0 EN 1602
Density – apparent core kg/m³ 40.0 EN 1602
Compression strength @ 10% kPa 200 EN 826
Thermal conductivity mW/mK 23.3 EN 12667
Tensile adhesion kPa 250 EN 1607
Dimensional stability –20°C % <1.0 EN 1604
Dimensional stability +70°C % <2.0 EN 1604
Closed cell content % >90 ISO 4590

The above properties are typical of what can be expected when BASF foam is processed using recommended procedures.The values above were obtained by foam samples produced in BASF laboratories.