What is the thermal insulation performance of polyurethane (PU)?

What is the thermal insulation performance of polyurethane (PU)?

Polyurethane (PU) offers excellent thermal insulation properties, as demonstrated in the following aspects:

• Low thermal conductivity: When the density of polyurethane rigid foam is 35-40 kg/m³, its thermal conductivity is only 0.018-0.023 W/(m·K), the lowest among all currently available insulation materials. In comparison, the thermal conductivity of polystyrene (EPS) is 0.038-0.042 W/(m·K), that of extruded polystyrene (XPS) is 0.028-0.035 W/(m·K), and that of rock wool is 0.035-0.045 W/(m·K).

• Closed-cell structure: Polyurethane has a unique closed-cell structure with a closed-cell ratio exceeding 90%. It is a hydrophobic material, meaning its thermal conductivity does not increase due to moisture absorption, and water does not penetrate the wall surface. This closed-cell structure effectively prevents heat transfer, giving polyurethane excellent thermal insulation properties. Stable Long-Term Thermal Insulation: Polyurethane's unique closed-cell properties and high resistance to gas diffusion provide it with superior long-term insulation performance, capable of maintaining thermal insulation for 20-50 years or longer. Under normal use and maintenance, the average lifespan of polyurethane insulation materials can exceed 30 years.

• Application Advantages: Polyurethane insulation materials can be applied by direct spraying or pouring, creating a seamless, integrated insulation layer. This avoids thermal bridging at the joints of traditional insulation materials and further enhances insulation effectiveness.