We are a top fireproof door manufacturer in China and would like to share some useful knowledge about fireproof doors. This is a practical blog that shares the production process diagram of fire doors, with sufficient theoretical basis and strong practical significance. It can be applied to most standard fire door manufacturing processes, hoping to […]
Tag Archives: Steel fire proof door production process
Steel Fireproof Door Production Process: Step-by-Step
1. Material Preparation
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Steel Coils: 18-20 gauge (1.0–1.5mm) galvanized steel
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Fireproof Core: Mineral wool, vermiculite, or gypsum board
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Intumescent Materials: Strips & seals (expand at 200–300°C)
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Hardware: Fire-rated hinges (3+ per door), locks, and closers
2. Step-by-Step Manufacturing
Step 1: Steel Sheet Processing
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Cutting: Laser/plasma cutting of steel sheets to door size
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Stamping: Forms panel design (smooth, ribbed, or wood-grain)
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Bending: Edges folded for structural rigidity
Step 2: Frame & Reinforcement
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Steel Frame Welding: Rectangular frame (1.5–2mm steel)
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Lock Reinforcement: Steel plate welded at lock area
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Hinge Reinforcement: Steel sleeves for heavy-duty hinges
Step 3: Core Assembly
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Core Placement: Fireproof material (mineral wool/vermiculite) inserted between steel sheets
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Adhesive Bonding: High-temperature epoxy secures core
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Hydraulic Pressing: 100–200 tons pressure for uniform bonding
Step 4: Intumescent Sealing
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Perimeter Seals: Intumescent strips glued into grooves
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Glazing Seals (if applicable): Fire-rated silicone for glass edges
Step 5: Surface Treatment
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Phosphating: Anti-rust chemical bath
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Powder Coating: Electrostatic spray + oven curing (200°C)
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Optional: Wood-grain embossing or decorative finishes
Step 6: Hardware Installation
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Hinges: 3–4 stainless steel butt hinges (melting point >800°C)
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Locks: UL-listed mortise or panic hardware
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Closers: Adjustable self-closing mechanism
Step 7: Glazing (Optional)
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Fire-Rated Glass: Ceramic or wired glass (tested to same rating as door)
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Beading System: Steel retainers with intumescent gaskets
Step 8: Quality Control
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Dimensional Check: ±2mm tolerance
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Fire Test Sample: Furnace testing to verify rating
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Cycle Testing: 100,000 open/close cycles
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Smoke Seal Test: Air leakage <25m³/h·m² (EN1634-3)
3. Key Production Equipment
| Machine | Function |
|---|---|
| CNC Plasma Cutter | Precision steel cutting |
| Hydraulic Press | Core bonding (100+ tons) |
| Powder Coating Line | Surface finishing |
| Intumescent Strip Applicator | Automated seal installation |
| Fire Test Furnace | Certification testing |
4. Fire Rating Compliance
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UL10C (USA): 30-180 minute ratings
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EN1634 (EU): EI30-EI120 classifications
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BS476 (UK): Part 22 certification
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Mandatory Markings: Permanent label with manufacturer, rating, test standard
5. Production Time & Output
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Standard Door: 4–6 hours production time
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Custom Door: 1–2 weeks (design + testing)
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Factory Capacity: 50–200 doors/day (medium-scale plant)
6. Common Defects & Solutions
| Issue | Cause | Fix |
|---|---|---|
| Warping | Uneven core density | Adjust hydraulic pressure |
| Poor Fire Rating | Seal failure | Reapply intumescent strips |
| Rust Spots | Incomplete coating | Re-phosphating + coating |
| Sticking Closer | Misaligned frame | Adjust hinge shims |
7. Industry Trends
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Smart Fire Doors: IoT-enabled sensors for real-time monitoring
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Hybrid Materials: Steel-composite designs for lighter weight
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Sustainable Cores: Recycled mineral wool alternatives
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Modular Systems: Pre-assembled door-frame units
8. Top-Grade Production Checklist
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Steel Quality: ASTM A653 galvanized
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Core Density: ≥110kg/m³ for 90+ min rating
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Seal Coverage: Continuous 4-sided application
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Hardware Certification: UL/EN-certified
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Final Inspection: 100% tested before shipping
This process combines precision engineering with fire science to create doors that save lives. For specialized needs (bullet-resistant + fireproof, radiation shielding, etc.), additional layers and testing are incorporated.