Detailed explanation of the compressive strength of PU foam

In various insulation projects and industrial fields, polyurethane foam is widely used for its excellent thermal insulation performance. But do you know that the compressive strength of polyurethane foam with different densities and processes varies greatly , which directly affects the service life and safety performance?

If you already know the density you're targeting, our PU foam density & material calculator converts it into the exact kg of A/B system you need to order.

Compression performance at different densities

Conventional insulation (60–80 kg/m³)
is ≥ 0.3 MPa , which is suitable for underground direct insulation and roof insulation, and can effectively resist soil loads and daily mechanical shocks.

The high-density reinforcement layer (≥80 kg/m³)
has a compressive strength of ≥ 1.0 MPa and is suitable for occasions with higher pressure requirements, such as cold storage floors and industrial heavy-load areas.

Special modified formula scenario:
The modified polyurethane (with heat-resistant additives added) used in high temperature environment can achieve a compressive strength of more than 1.5 MPa . When used in steam pipelines, the system pressure can reach ≥12 MPa.

Key factors affecting compressive strength

Closed cell rate : The higher the closed cell rate, the stronger the compressive resistance. The closed cell rate of high-quality foams in the industry generally reaches more than 90% , and some high-end formulas can reach 97% .

Construction technology : Adopt high-pressure "tube-in-tube" foaming system, and the foaming pressure is controlled at ≥0.5 MPa to ensure that the foam filling is uniform and dense.

Temperature coordinated control : The foaming process is best controlled at 20-30℃; if the temperature difference exceeds ±2℃, the foaming pressure needs to be adjusted to compensate to ensure pressure resistance consistency.

Engineering recommendations

Material selection should not only consider cost, but also match the corresponding density and compressive parameters according to the actual usage scenario. For example, direct buried heating pipes only need ≥0.3 MPa, while high-temperature steam pipelines must choose modified foam ≥1.5 MPa.

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