Fire Door Composite Frame Geometry Retention
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Solution Overview
Problem
Conventional fire doors experience deformation and failure when exposed to heat due to differential expansion between thin steel sheets and the plaster core, allowing fire to pass through, and existing designs lack sufficient rigidity and insulation to effectively prevent fire spread.
Innovation Solution
A fire door design featuring a composite material frame with U-shaped profiles and thermosetting matrix, filled with expanding foam, and intumescent seals to maintain geometry and rigidity under heat exposure, ensuring effective fire barrier functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thin steel sheets (0.8-1mm) are used for facing sheets, then the door can be manufactured with standard materials, but the sheets deform and wrinkle under heat due to differential expansion with the plaster core
Solution Approach 1:
The patent applies composite materials by combining metal facing sheets with a calcium silicate board core instead of traditional plaster. This composite construction resolves the differential expansion issue because calcium silicate board has thermal expansion properties more compatible with metal sheets, preventing the wrinkling and deformation that occurs with plaster cores under fire conditions.
Solution Approach 2:
The patent changes the material parameters of the core from plaster to calcium silicate board, which has different thermal and mechanical properties. This parameter change ensures that the core material maintains its dimensional stability under heat exposure, preventing the facing sheets from deforming while still allowing standard thin gauge metal sheets to be used.
2Strength
If thicker metal sheets are used for facing sheets, then the door can withstand impacts better, but the sheets deform under heat due to differential expansion with the core
Solution Approach 1:
The patent uses a composite core of calcium silicate board that is specifically designed to match the thermal expansion characteristics of the metal facing sheets. This allows the use of thicker metal sheets for improved impact resistance without the deformation problem, because the composite core prevents differential expansion under heat.
3Ease of manufacture
If a plaster core is used, then the door structure is simple and easy to manufacture, but the plaster deforms under heat causing the door to lose its flat geometry
Solution Approach 1:
The patent changes the core material parameter from plaster to calcium silicate board, which has superior dimensional stability under thermal stress. This material substitution maintains the simplicity of manufacturing while preventing the core from deforming under heat, thereby preserving the flat geometry of the door during fire exposure.
4Ease of manufacture
If conventional fire door structures are used, then the door can be manufactured with standard materials, but the door lacks sufficient rigidity and insulation to effectively prevent fire spread
Solution Approach 1:
The patent employs a composite construction with calcium silicate board core and metal facing sheets, creating a structure with enhanced fire resistance. The calcium silicate board provides superior thermal insulation and structural integrity at high temperatures, while the metal facing sheets maintain their strength and prevent flame penetration, achieving effective fire spread prevention.
Solution Approach 2:
The calcium silicate board core contains a porous structure that provides thermal insulation, preventing heat transfer through the door assembly. This porous material structure enhances the fire resistance by creating thermal barriers while maintaining the overall structural integrity of the door during fire exposure.
Data Source
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AI summary
The present invention relates to a door, particularly a fire-resistant one (100), comprising a core, two facing sheets arranged opposite each other and on either side of the core, each facing sheet comprising a main flat (Pp) and polygonal wall, the door including a frame (Cd) formed of a plurality of profiles (Po) butted together in pairs so as to delimit the perimeter of said frame, each profile (Po) having in section a U-shaped geometry defined by an intermediate flange (Ai) extended at its two ends by two parallel lateral flanges (Al1 and Al2), which are turned outwards, the main wall (Pp) of each facing sheet (Ft) resting on the turned lateral flanges (Al) of the same edge of said frame, the main wall (Pp) of each facing sheet (Ft) being extended respectively on several of its sides by edge walls (P1, P2,P4) and which are folded almost parallel to said main wall so that said facing sheet (Ft) can be hung on said frame, the turned lateral wings (Al) of the same edge of said frame being held between the main wall (Pp) and said border walls (P1, P2, P4). According to the invention, the profiles (Po) are made of a thermosetting matrix composite material. The two lateral wings of the profile remain behind the two facing sheets and are thus not directly exposed to the effects of the flame. They retain their geometry and make it possible to maintain the flatness of the fire door in the event of a fire so that it can prevent the spread of fire.