In building electromechanical, HVAC, chilled water, and industrial pipeline insulation systems, rubber-plastic and polyurethane insulation materials are common choices. Both are high-efficiency insulation materials, but they differ significantly in material structure, physical properties, construction methods, and applicable working conditions. A systematic comparison of rubber-plastic and polyurethane insulation materials helps in making more rational material selections in practical projects.

I. Comparison of Material Structure and Basic Characteristics

Rubber-Plastic Insulation Materials

Rubber-plastic materials typically use synthetic rubber as a base material, forming a uniform closed-cell structure through a foaming process. Their main characteristics are good flexibility and high elasticity. The material itself has certain waterproof, moisture-proof, and condensation-proof capabilities, making it suitable for covering the surfaces of pipes and equipment.

Polyurethane Insulation Materials

Polyurethane insulation materials are mostly rigid foam structures, forming a high-density closed-cell system through chemical foaming. They have high rigidity and a stable overall structure, and are often used in insulation projects in the form of sheets, pipe shells, or on-site spraying.

Structurally, rubber-plastic is a flexible insulation material, while polyurethane is a typical rigid insulation material. II. Comparison of Thermal Conductivity and Insulation Performance

The thermal conductivity of rubber and plastic insulation materials is generally in the range of 0.032–0.040 W/(m·K), exhibiting stable insulation performance under medium and low temperature conditions, making them particularly suitable for air conditioning systems and refrigerant pipelines.

The thermal conductivity of polyurethane insulation materials is typically lower, generally between 0.022–0.030 W/(m·K). Under the same insulation requirements, polyurethane requires a smaller thickness, making it suitable for scenarios with high insulation efficiency requirements or limited space.

Overall, polyurethane has a slight advantage in pure insulation efficiency, while rubber and plastic can meet most needs under conventional HVAC conditions.

III. Comparison of Anti-condensation and Moisture-proof Performance

Rubber and plastic materials have a closed-cell structure and low water vapor permeability, inherently possessing anti-condensation capabilities. They are widely used in systems with high condensation risk, such as chilled water pipes and refrigerant pipelines, typically eliminating the need for an additional moisture-proof layer.

Polyurethane, while also a closed-cell structure, can still allow moisture to enter the insulation layer through joints or cracks in practical engineering if the surface protective layer is damaged. Therefore, polyurethane systems typically require the use of a protective layer or outer sheath to ensure long-term moisture resistance.

Regarding condensation resistance, rubber-plastic materials offer relatively higher engineering tolerance.

IV. Comparison of Construction and Installation Ease

Rubber-plastic insulation materials are highly flexible and can be directly cut and wrapped around pipes and irregularly shaped equipment. Construction is simple, and they are highly adaptable to complex surfaces, making them particularly suitable for confined spaces and densely packed pipelines in computer rooms.

Polyurethane insulation materials are mostly prefabricated pipe shells or spray-applied, requiring higher construction precision. Pipe shell installation requires tight joints, while spray application demands stricter environmental and process control, resulting in a relatively longer construction period.

In terms of construction flexibility, rubber-plastic materials have an advantage; however, in large, regular systems, polyurethane is more conducive to standardized construction.

V. Comparison of Durability and Service Life

Rubber-plastic materials possess good elasticity and vibration resistance, and are not prone to cracking under temperature changes and equipment vibration. However, long-term exposure to high temperatures or strong ultraviolet radiation requires attention to material aging.

Polyurethane materials have a stable structure and exhibit minimal long-term degradation in thermal insulation performance. However, under low-temperature or alternating hot and cold conditions, inadequate external protection may lead to localized cracking or detachment.

Under proper construction and protective conditions, both materials can meet long-term service requirements, but their failure modes differ.

VI. Comparison of Typical Application Scenarios

Rubber-plastic insulation materials are more suitable for:

Central air conditioning systems

Chiller water pipes, refrigerant pipes

Building machine rooms and equipment insulation

Places with high requirements for anti-condensation

Polyurethane insulation materials are more suitable for:

Systems with high requirements for insulation efficiency

Cold storage, low-temperature storage facilities

Industrial equipment and large pipelines

Scenarios with limited space but permissible rigid structures

VII. Comprehensive Selection Recommendations

There is no absolute superiority or inferiority between rubber-plastic and polyurethane insulation materials; their suitability depends on specific project requirements:

If the project prioritizes ease of construction, anti-condensation performance, and system flexibility, rubber-plastic insulation materials are more suitable;

If the project has high requirements for insulation efficiency, thickness control, and overall structural stability, then polyurethane insulation materials are more advantageous.