In industrial piping and building HVAC systems, the selection of pipe insulation materials directly affects the system's energy-saving effect, safety performance, and subsequent maintenance costs. Rock wool and rubber-plastic composites are two widely used insulation materials, each with its own advantages and applicable boundaries in pipe insulation projects. This article will compare the applicability of rock wool and rubber-plastic composites in pipe insulation, systematically analyzing their material characteristics, insulation performance, anti-condensation ability, fire resistance requirements, and construction adaptability to provide a reference for project selection.

I. Comparison of Material Structure and Basic Properties

1. Material Structural Characteristics of Rock Wool

Rock wool is made from natural rocks such as basalt as the main raw material, melted at high temperatures and then fiberized. It is a typical inorganic fiber insulation material. Its fibers have a three-dimensional interwoven structure and contain a large amount of still air, which helps reduce heat conduction.

Rock wool itself is non-combustible and has outstanding high-temperature resistance, giving it a significant advantage in high-temperature pipelines and systems with high fire resistance requirements.

2. Structural Characteristics of Rubber-Plastic Insulation Materials

Rubber-plastic insulation materials are mainly made of foamed synthetic rubber with a closed-cell structure, low water vapor permeability, and good flexibility, allowing them to tightly adhere to the pipe surface. Rubber-plastic materials are widely used in medium- and low-temperature piping systems, especially suitable for scenarios with high requirements for preventing condensation.

II. Comparison of Insulation Performance and Thermal Conductivity

Performance of Rock Wool in Pipe Insulation

The thermal conductivity of rock wool is typically 0.036–0.045 W/(m·K), maintaining relatively stable insulation performance even in medium- and high-temperature environments. For steam pipes, hot water pipes, and industrial high-temperature pipelines, rock wool can operate for extended periods without performance degradation.

Performance of Rubber-Plastic Insulation in Pipe Insulation

The thermal conductivity of rubber-plastic materials is generally 0.032–0.038 W/(m·K), exhibiting good insulation performance in the medium- and low-temperature range. Its advantage lies in its stable thermal conductivity at low temperatures, making it ideal for chilled water pipes and air conditioning systems.

From a thermal conductivity perspective, both are numerically similar, but their applicable temperature ranges differ, determining their respective application focuses in pipe insulation.

III. Comparison of Anti-Condensation Performance

Rock Wool's Anti-Condensation Capacity

Rock wool has an open-cell fiber structure. If moisture-proofing measures are inadequate, water vapor can easily penetrate the insulation layer, affecting the insulation effect and increasing the risk of condensation. Therefore, when rock wool is used for pipe insulation, it usually needs to be used in conjunction with moisture-proof layers such as aluminum foil or galvanized iron sheets.

Rubber and Plastic's Anti-Condensation Advantages

Rubber and plastic materials have a closed-cell structure and low water vapor permeability, possessing excellent anti-condensation performance. In low-temperature systems such as chilled water pipes and refrigerant pipes, rubber and plastic can operate stably with minimal additional moisture-proofing measures.

IV. Comparison of Fire Resistance and Safety Requirements

Rock Wool's Fire Resistance Applicability

Rock wool is a non-combustible material with excellent high-temperature resistance. In the event of a fire, it does not support combustion or produce harmful gases, and is often used in industrial pipelines and building manhole systems with strict fire protection requirements.

Fire Resistance Properties of Rubber and Plastics

Rubber and plastic materials are generally flame-retardant. Provided they meet building code requirements, they can be used for pipe insulation. However, their fire resistance rating is usually lower than that of rock wool, making them more suitable for systems with relatively conventional fire protection requirements.

V. Comparison of Construction Adaptability and Maintenance

Rock Wool Construction Characteristics

Rock wool is relatively hard, requiring cutting, binding, and installation with an outer protective layer during construction. The process is relatively complex, but the resulting structure is stable and suitable for long-term industrial piping systems.

Rubber and Plastic Construction Advantages

Rubber and plastic materials are highly flexible and can be directly applied to the pipe surface, resulting in high construction efficiency. They are particularly suitable for complex pipeline systems with small diameters and many bends. Subsequent maintenance and replacement are also relatively convenient.

VI. Comparison of Typical Application Scenarios

| Application Scenarios | Rock Wool | Rubber & Plastic |

| ------------------- | --------- | ----- |

| High-Temperature Steam Pipelines | ✔ Preferred | ✖ Not Suitable |

| Hot Water Pipelines | ✔ Applicable | ✔ Applicable |

| Chilled Water Pipelines | △ Requires Moisture Protection | ✔ Preferred |

| Refrigerant Pipelines | △ General | ✔ Preferred |

| Pipe Wells with High Fire Resistance Requirements | ✔ Preferred | △ Limited |

VII. Comprehensive Selection Recommendations

In summary, the differences in applicability between rock wool and rubber/plastic insulation for pipe insulation mainly lie in temperature range, anti-condensation requirements, and fire resistance ratings:

For high-temperature and fire-resistant pipe systems, rock wool is more advantageous.

For low-temperature pipe systems with high requirements for anti-condensation and construction efficiency, rubber/plastic is more suitable.

In special operating conditions, different materials can be combined to leverage their respective advantages.

In pipeline insulation projects, there is no single "absolutely better" material. Rock wool and rubber-plastic composites are each suitable for different pipeline operating conditions and design objectives. A reasonable understanding of the differences between the two in terms of insulation performance, anti-condensation, fire resistance, and construction is key to achieving a safe, efficient, and economical pipeline insulation system.