Phenolic Foam——Innovative foam insulation material, better than EPS&XPS

Due to modern buildings' requirements for the safety, thermal insulation performance, and environmental friendliness of insulation materials, many new materials are increasingly being applied in the construction industry. Foam materials constitute a significant category among these.

Among them, Phenolic Foam board (hereafter referred to as PF) has become a widely popular choice due to its superior performance.

I. Outstanding Fire Resistance

PF insulation material is a thermosetting material. It is produced using phenolic resin as the main raw material, which undergoes self-crosslinking foaming and curing under the action of a catalyst. Due to the inherent properties of phenolic resin, it possesses a certain degree of fire resistance inherently. Without the addition of extra flame retardants, PF can already achieve the Class B1 non-combustibility rating. PF insulation boards produced through technical modification can even reach the Class A1 non-combustibility rating.

A key characteristic of PF boards is that under direct exposure to ultra-high temperatures and open flames, they form a charring skeleton and release gaseous products like CO and CO₂. These gases not only dilute the concentration of flammable gases and oxygen in the combustion zone but also have a smothering effect. There is no flame propagation or spread; only surface charring occurs without molten dripping, demonstrating excellent resistance to flame penetration.

Common eps/XPS foam materials are linear polymers, belonging to thermoplastic materials. They can achieve Class B1 non-combustibility by adding flame retardants. However, due to the arbitrary nature of added flame-retardant materials, their quality is often unstable, prone to defects and significant fluctuations. In contrast, thermosetting PF offers better high-temperature stability. Given its significantly superior fire resistance compared to EPS and XPS, PF is the outstanding choice where building fire safety requirements exist.

II. Excellent Thermal Insulation Performance

Thermal conductivity (λ-value) is a physical quantity measuring the heat transfer capability of a single material. Thermodynamic theory demonstrates that the lower the thermal conductivity of an insulation material, the greater its thermal resistance, and the better its insulating effect. PF has a uniformly distributed micro closed-cell structure, endowing it with a low thermal conductivity. The thermal conductivity values of common foam insulation materials compared to phenolic foam are as follows:

•   PF ≤ 0.023 W/m·K

•   PUR ≤ 0.024 W/m·K

•   EPS ≤ 0.041 W/m·K

•   XPS ≤ 0.030 W/m·K

•   GXPS ≤ 0.038 W/m·K

This means that to achieve the same insulation effect, PF requires the least amount of material, saving space and reducing construction time.

III. Superior High-Temperature Stability

The high-temperature resistance of insulation materials is often overlooked. During hot summers, the temperature of insulated walls can become very high. Combined with the low thermal conductivity of the insulation material, heat is retained within the foam rather than transferring into the wall, easily causing the insulation boards to bulge, warp, or undergo other deformations. PF possesses the advantage of high-temperature resistance. When used for building envelope insulation, PF boards will not deform due to factors like prolonged exposure to high temperatures during hot weather, elevated substrate temperatures, or other high-temperature conditions, such as shrinkage or expansion. Below is a comparison of material high-temperature stability:

•   PF: ≤ 210°C without deformation or discoloration

•   PUR: ≤ 120°C without deformation

•   PS/GEPS/XPS: ≤ 80°C without deformation

IV. Enhanced Environmental Friendliness

PF utilizes environmentally friendly pentane-based blowing agents, which do not impact the environment. Furthermore, it contains no added flame retardants, eliminating the release of harmful gases. Long-term use poses no risk to human health.

V. Application Scope

PF boards can be applied in External Thermal Insulation Composite Systems (ETICS), Integrated Exterior Wall Insulation and Decoration Systems, HVAC systems, as well as in aircraft, ships, and other fields. Different types can be selected according to specific requirements.

Conclusion:

From the perspective of the building insulation industry's development, PF board production causes no environmental pollution. It offers multiple advantages in product performance and application technology, including high-efficiency insulation, fire resistance and flame retardancy, low density, stable performance, and environmental and health safety. It is an insulation material with enormous potential.