Fire Door Strip with Intumescent Chambers and Interlocking Edges
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Solution Overview
Problem
Existing fire-resistant slats for doors suffer from preferential flame passages between slats, complex cable attachment issues leading to tension-induced degradations, limited resistance to burglary, shocks, and blasts, and inadequate heat resistance, especially during intense fires and temperature differences.
Innovation Solution
A fire-resistant slat design featuring a plastic casing with intumescent material and a metal profile that divides the casing into separate chambers, with longitudinal grooves and protuberances for secure slat connection, and hooked edges for forming a continuous wall, enhancing heat distribution, flame resistance, and mechanical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If slats are attached by steel cables passing through grooves and protuberances, then the door can be assembled, but the cables induce tension that causes degradations at the protrusions or grooves during curved movement
Solution Approach 1:
The patent removes the steel cables from the system entirely. Instead of using cables to connect slats, the invention uses direct mechanical interlocking through grooves and protuberances that are integrated into the slat structure itself, eliminating the source of tension-induced degradations
Solution Approach 2:
The connection function previously performed by separate steel cables is merged into the slat structure itself. The grooves and protuberances are built-in features of the slats, combining the structural element with its connection mechanism, thereby eliminating the need for external cables that cause tension problems
2Reliability
If the door is not lowered correctly, then passages can be formed between adjacent slats, but ensuring optimal alignment is complex and may not prevent flame passage during fire
Solution Approach 1:
The patent incorporates intumescent material within the slat structure that activates when exposed to heat. This material expands beforehand to fill any gaps or passages that may form between slats, providing a backup protection mechanism that works regardless of alignment issues
Solution Approach 2:
The invention applies different properties to different parts of the slat system. The grooves and protuberances have specific geometric properties for mechanical connection, while the intumescent material provides thermal-responsive properties. This localized differentiation allows the system to maintain fire protection through multiple mechanisms
3Strength
If metal sections are used with hooks for slat connection, then mechanical strength is improved, but the outer chamber melts and/or is consumed during fire, creating passages between metal profiles
Solution Approach 1:
The patent uses composite construction combining plastic material for the slat body with intumescent material filling. This composite structure provides both the mechanical strength needed for connection and the fire resistance required, as the intumescent material chars and expands to protect the underlying structure during fire exposure
Solution Approach 2:
The invention converts the harmful effect of heat into a beneficial protective mechanism. The intumescent material is designed to react to heat by expanding and forming a protective char layer, transforming the fire hazard into an active defense mechanism that prevents flame and heat passage
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design provides improved resistance to flame passage, heat, burglary, shocks, and blasts, maintaining temperature below 140°C, and ensuring airtightness and adhesion of slats, even when not optimally aligned, with enhanced protection against wear and corrosion.
Implementation Method 1
an intumescent material at least partially filling said chamber
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The strip (2) has a metallic section (30) provided with longitudinal edges (30bis, 30ter) and extended from a longitudinal envelope to define distinct chambers. A longitudinal edge of the strip and a longitudinal edge of another strip (2bis) are adapted with respect to one another, to limit or avoid relative displacement of a gap of the strip (2) with respect to the strip (2bis). Another longitudinal edge of the strip (2) and an edge of a third strip (2ter) are adapted with respect to one another, to limit/avoid relative displacement of a gap of the strip (2) with respect to the strip (2ter). The envelope is made of thermoplastic/thermoformable material. The chambers are completely filled with composition containing intumescent material. Independent claims are also included for the following: (1) a door or partition comprising a series of fire resistant strips (2) a method for fabricating strips.