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What grade of material is thermosetting polystyrene board?
2025-06-28

In the field of building insulation materials, thermosetting polystyrene board, as a new type of insulation material, has attracted much attention for its fire performance level. So, what grade of fireproof material does thermosetting polystyrene board belong to? This article will provide you with a detailed analysis of this important issue.

1、 Basic characteristics of thermosetting polystyrene board

Thermosetting polystyrene board is a new type of thermal insulation material obtained by modifying the traditional polystyrene foam board (EPS). It retains the lightweight and excellent insulation properties of EPS, while significantly improving its fire resistance through the addition of flame retardants and special processing techniques. This material has a low thermal conductivity (usually between 0.032-0.040W/(m · K)) and excellent insulation effect, making it an ideal choice for building energy conservation.

2、 Classification of fire performance levels

According to the national standard GB8624-2012 "Classification of Combustion Performance of Building Materials and Products" in China, the fire protection level of building materials is divided into four levels: A, B1, B2, and B3:

Grade A: Non combustible material

B1 level: flame retardant material

B2 level: Combustible materials

B3 level: flammable material

3、 Fire rating of thermosetting polystyrene board

Specially treated thermosetting polystyrene board can meet the standard of B1 level flame retardant material. Specifically manifested as:

Combustion performance: self extinguishing within 3 seconds after leaving the fire

Oxygen index: ≥ 30%

Smoke density grade: ≤ 75

Burning droplets/particles: No production

It should be noted that ordinary unmodified polystyrene board can usually only reach B2 level, while thermosetting polystyrene board significantly improves its fire resistance by adding phosphorus nitrogen flame retardants and cross-linking modification treatment.

4、 Comparison with other insulation materials

Rock wool board: A-grade non combustible material

Extruded polystyrene board (XPS): usually B1 grade

Polyurethane board: usually B2 grade

Graphite polystyrene board: usually B1 grade

5、 Application suggestions

Thermosetting polystyrene board is particularly suitable for:

Public buildings with high fire prevention requirements

External wall insulation of high-rise residential buildings

In situations where it needs to be used in conjunction with fire barriers

Conclusion

As an improved insulation material, thermosetting polystyrene board achieves a good balance between insulation and fire resistance with its B1 level fire resistance rating. Although not as non combustible as A-class materials, considering the insulation performance, cost, and fire protection requirements, thermosetting polystyrene board is undoubtedly one of the most cost-effective choices in the current field of building insulation. When selecting, attention should be paid to reviewing the product's testing report to ensure that it truly meets the B1 level standard.