Fireproof board core paper is the central layer of fireproof boards (also known as refractory boards), directly influencing their flame resistance, mechanical strength, and environmental properties. Through multilayer structural design and polymer composite technology, it serves as a critical safeguard for fire safety in construction, transportation, and industrial applications.
Material and Structure
The core paper primarily consists of two materials:
- Kraft Paper-Based Core Paper: High-density kraft paper impregnated with phenolic resin forms a dense laminated structure under high temperature and pressure, providing high strength and impact resistance.
- Mineral Fiber Core Paper: Traditional asbestos-containing or modern asbestos-free fibers (e.g., calcium silicate, mica) enhance fire resistance (1–4 hours) through flame-retardant impregnation.
The core paper typically has 3–10 layers, a grammage of 80–200g/m², and thicknesses adjustable from 3–25mm.
Production Process
- Impregnation Process: Kraft paper or mineral fibers are saturated with phenolic or melamine resins (20–30% adhesive content) to ensure uniform flame-retardant distribution.
- High-Pressure Curing: Cured at 140–160°C under 10–20MPa pressure, forming a low-porosity structure that effectively blocks heat transfer.
- Eco-Innovation: Some manufacturers use recycled paper instead of wood pulp, reducing costs by 30–40% through high-concentration pulping and medium-concentration refining while conserving resources.
Core Performance
✅ Flame Retardancy: Forms a carbonized layer upon exposure to fire, delaying flame spread, compliant with GB8624 Class A (China) and EN13501 Class B (EU) standards.
✅ Low Smoke and Toxicity: Halogen-free formulations produce smoke density <50Dm, meeting green building requirements.
✅ Stability: Heat-resistant (up to 800°C), moisture-resistant with deformation rate <0.5%, and hygroscopic expansion rate of 0.25%, suitable for high-humidity environments.
✅ Lightweight Trend: Honeycomb-structured core paper reduces weight by 30% while maintaining fire resistance, driving energy-efficient material development.
Applications
- Construction: Fireproof partitions, escape route panels, exterior wall cladding.
- Transportation: High-speed train interiors, ship bulkheads, balancing lightweight and fireproof needs.
- Industrial Facilities: Flame-retardant cable ducts, laboratory countertops.
Industry Trends
- Eco-Upgrades: Asbestos-free, low-formaldehyde core papers dominate, complying with international certifications like EN13501-1.
- Smart Manufacturing: Integration of automation and nanotechnology improves product uniformity and functionality.
Conclusion: Fireproof board core paper drives flame-retardant materials toward efficiency and sustainability through innovation, securing public safety. Its potential lies in lightweight and smart applications