What is the most important property for PU foam insulation according to this standard?

Thermal conductivity. The standard specifies a maximum initial value of 0.029 W/(m.K) as per Table 1, which is the primary measure of its insulation capability.

What are the standard density classes for PU foam in IS 12436?

The standard specifies nominal densities such as 32, 40, 48, and 60 kg/m³, with an allowable tolerance of ±3 kg/m³ (Clause 4.1.1).

How is compressive strength measured?

It's measured at 10 percent deformation in a direction parallel to foam rise. For a 32 kg/m³ density foam, the minimum strength required is 1.5 kgf/cm² (Table 1).

Does this standard cover fire safety aspects?

It references IS 11239 (Part 3) for the test method for surface burning characteristics but does not set specific limits, stating they shall be as agreed between the purchaser and the supplier (Clause 5.7).

IS 12436

: 1988

Specification for rigid polyurethane (PU) foam for thermal insulation

CurrentSpecializedSpecificationBIMMaterials Science · Insulation Materials

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This Indian Standard specifies the requirements, testing methods, and sampling procedures for rigid polyurethane (PU) foam intended for use as thermal insulation. It covers essential physical properties such as density, thermal conductivity, compressive strength, and dimensional stability to ensure material quality for applications like cold storage and building insulation.

Specifies requirements for rigid polyurethane (PU) foam used for thermal insulation.

Quick Reference Values

Maximum Thermal Conductivity (Initial)0.029 W/(m.K)

Minimum Closed Cell Content90 %

Minimum Compressive Strength at 10% deformation1.5 kgf/cm²

Maximum Water Vapour Permeability4.0 perms-cm

Nominal Density Range32 to 60 kg/m³

Practical Notes

This standard is critical for Quality Assurance (QA) of insulation material on-site or at the factory. Always ask for a manufacturer's test certificate referencing IS 12436.

The 'closed cell content' is a key parameter for long-term performance, as high open-cell content can lead to moisture absorption and degradation of thermal resistance.

While the standard was published in 1988, it has been reaffirmed multiple times (e.g., 2004, 2014, 2019), indicating it is still the current and valid specification in the absence of a newer version.